Kerberos is an authentication system that allows clients to securely request services from servers across an insecure network. It was developed at MIT to prevent passwords from being sent in unencrypted form. This document provides an overview of Kerberos, including its goals of providing secure authentication, a history of its development from versions 1-5, and concepts like tickets, encryption, and cross-realm authentication. It also discusses Kerberos applications, security issues and solutions, and potential future developments like smart cards and better encryption standards.
Kerberos is an authentication protocol that uses symmetric cryptography to allow nodes on an insecure network to prove their identity to one another. It was developed at MIT to allow users to securely access services over the university's network. Kerberos uses tickets and authenticators encrypted with shared keys to verify users' identities without transmitting passwords over the network. It provides secure authentication through a trusted third party called the Key Distribution Center that issues tickets for authentication.
This document discusses network session security and prevention mechanisms. It proposes using stochastic fingerprints instead of SSL to securely encrypt network traffic. This approach implements intrusion prevention at the server side and is more efficient than SSL. It also uses machine learning to further improve intrusion detection by analyzing prevention strategy parameters. Session keys play an important role in authentication and secure communication between clients and servers. The proposed method provides faster authentication using tickets and more security than other approaches like ticket granting servers.
Solving Downgrade and DoS Attack Due to the Four Ways Handshake Vulnerabiliti...Dr. Amarjeet Singh
The growing volume of attacks on the Internet has
increased the demand for more robust systems and
sophisticated tools for vulnerability analysis, intrusion
detection, forensic investigations, and possible responses.
Current hacker tools and technologies warrant reengineering
to address cyber crime and homeland security. The being
aware of the flaws on a network is necessary to secure the
information infrastructure by gathering network topology,
intelligence, internal/external vulnerability analysis, and
penetration testing. This paper has as main objective to
minimize damages and preventing the attackers from
exploiting weaknesses and vulnerabilities in the 4 ways
handshake (WIFI).
We equally present a detail study on various attacks and
some solutions to avoid or prevent such attacks in WLAN.
The document summarizes a research paper that proposes a method to prevent replay attacks in the Kerberos authentication protocol using triple passwords. The key aspects of the proposed method are:
1) Three passwords are stored on the Authentication Server and two passwords are sent to the Ticket Granting Server encrypted with a shared key.
2) The Ticket Granting Server sends one password to the Application Server encrypted with a shared key and the service ticket encrypted with the password received from the Authentication Server.
3) This prevents replay attacks because the attacker would not know the passwords to decrypt messages at different stages of authentication.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
1. The document proposes a framework to improve web services security called Robust Encryption and Decryption (RED). RED includes a common set of encryption algorithms deployed in browsers and web servers.
2. The framework also defines a Standard Encryption Syntax (SES) to allow web applications to communicate with RED for encrypting and decrypting content. Developers can select algorithms from RED and reference them using SES tags.
3. The framework aims to provide stronger encryption than SSL/TLS but with less complexity, cost, and performance impact. It could help secure communication against various network attacks.
Kerberos is a network authentication protocol developed at MIT in the 1980s. It uses secret key cryptography to authenticate users and services on an open network. When a user wants to access a service, Kerberos issues the user a ticket-granting ticket after verifying their credentials with the authentication server. The user can then use this ticket to request a ticket from the ticket granting server to access the specific service. This process prevents passwords from being sent across the network in plain text. Kerberos provides strong authentication but has the weakness that compromising the central server compromises authentication for all users.
This document proposes a machine learning approach using the Naive Bayes algorithm to detect distributed denial of service (DDoS) attacks through network intrusion detection. It first discusses the issues with existing intrusion detection systems, including long training times and low accuracy. It then summarizes research on applying various machine learning techniques like neural networks, decision trees, and Naive Bayes to intrusion detection. The proposed system would build a classifier using Naive Bayes, which provides faster training than other methods, to distinguish normal and attack traffic. This approach aims to improve upon the training time and detection accuracy of existing intrusion detection systems.
10. sig free a signature free buffer overflow attack blockerakila_mano
SigFree is a signature-free method for blocking buffer overflow attacks targeting internet services. It works by detecting the presence of executable code in messages, which legitimate requests do not contain. SigFree analyzes messages using a novel "code abstraction" technique to distill possible instruction sequences and prune non-code data using data flow analysis. It then determines if instruction sequences exceed thresholds for the number of useful instructions or dependence degree to identify code. Experimental tests showed SigFree could block over 750 known attacks with few false positives and negligible latency for normal requests.
Kerberos is an authentication protocol that uses symmetric cryptography to allow nodes on an insecure network to prove their identity to one another. It was developed at MIT to allow users to securely access services over the university's network. Kerberos uses tickets and authenticators encrypted with shared keys to verify users' identities without transmitting passwords over the network. It provides secure authentication through a trusted third party called the Key Distribution Center that issues tickets for authentication.
This document discusses network session security and prevention mechanisms. It proposes using stochastic fingerprints instead of SSL to securely encrypt network traffic. This approach implements intrusion prevention at the server side and is more efficient than SSL. It also uses machine learning to further improve intrusion detection by analyzing prevention strategy parameters. Session keys play an important role in authentication and secure communication between clients and servers. The proposed method provides faster authentication using tickets and more security than other approaches like ticket granting servers.
Solving Downgrade and DoS Attack Due to the Four Ways Handshake Vulnerabiliti...Dr. Amarjeet Singh
The growing volume of attacks on the Internet has
increased the demand for more robust systems and
sophisticated tools for vulnerability analysis, intrusion
detection, forensic investigations, and possible responses.
Current hacker tools and technologies warrant reengineering
to address cyber crime and homeland security. The being
aware of the flaws on a network is necessary to secure the
information infrastructure by gathering network topology,
intelligence, internal/external vulnerability analysis, and
penetration testing. This paper has as main objective to
minimize damages and preventing the attackers from
exploiting weaknesses and vulnerabilities in the 4 ways
handshake (WIFI).
We equally present a detail study on various attacks and
some solutions to avoid or prevent such attacks in WLAN.
The document summarizes a research paper that proposes a method to prevent replay attacks in the Kerberos authentication protocol using triple passwords. The key aspects of the proposed method are:
1) Three passwords are stored on the Authentication Server and two passwords are sent to the Ticket Granting Server encrypted with a shared key.
2) The Ticket Granting Server sends one password to the Application Server encrypted with a shared key and the service ticket encrypted with the password received from the Authentication Server.
3) This prevents replay attacks because the attacker would not know the passwords to decrypt messages at different stages of authentication.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
1. The document proposes a framework to improve web services security called Robust Encryption and Decryption (RED). RED includes a common set of encryption algorithms deployed in browsers and web servers.
2. The framework also defines a Standard Encryption Syntax (SES) to allow web applications to communicate with RED for encrypting and decrypting content. Developers can select algorithms from RED and reference them using SES tags.
3. The framework aims to provide stronger encryption than SSL/TLS but with less complexity, cost, and performance impact. It could help secure communication against various network attacks.
Kerberos is a network authentication protocol developed at MIT in the 1980s. It uses secret key cryptography to authenticate users and services on an open network. When a user wants to access a service, Kerberos issues the user a ticket-granting ticket after verifying their credentials with the authentication server. The user can then use this ticket to request a ticket from the ticket granting server to access the specific service. This process prevents passwords from being sent across the network in plain text. Kerberos provides strong authentication but has the weakness that compromising the central server compromises authentication for all users.
This document proposes a machine learning approach using the Naive Bayes algorithm to detect distributed denial of service (DDoS) attacks through network intrusion detection. It first discusses the issues with existing intrusion detection systems, including long training times and low accuracy. It then summarizes research on applying various machine learning techniques like neural networks, decision trees, and Naive Bayes to intrusion detection. The proposed system would build a classifier using Naive Bayes, which provides faster training than other methods, to distinguish normal and attack traffic. This approach aims to improve upon the training time and detection accuracy of existing intrusion detection systems.
10. sig free a signature free buffer overflow attack blockerakila_mano
SigFree is a signature-free method for blocking buffer overflow attacks targeting internet services. It works by detecting the presence of executable code in messages, which legitimate requests do not contain. SigFree analyzes messages using a novel "code abstraction" technique to distill possible instruction sequences and prune non-code data using data flow analysis. It then determines if instruction sequences exceed thresholds for the number of useful instructions or dependence degree to identify code. Experimental tests showed SigFree could block over 750 known attacks with few false positives and negligible latency for normal requests.
Detecting co residency with active traffic analysis techniquesYama Haku
The document proposes and evaluates techniques for detecting whether virtual machines are co-located on the same physical host using active network traffic analysis. It introduces a method called "co-resident watermarking" that embeds signals in the network flow of a target virtual machine using small packet delays. Experimental results show this approach can accurately detect co-residency between VMs within 10 seconds by analyzing the watermarked network traffic patterns. The study also explores potential defenses and limitations of the detection techniques.
This document is the final honors project report submitted by Antony Law comparing the security of simple versus complex passwords when implemented in WLAN security frameworks WPA and WPA2. The project aims to evaluate the impact of password complexity on resistance to password cracking attacks. An experiment will be conducted using the aircrack-ng and oclHashcat password cracking tools against various simple and complex password scenarios to determine differences in success rates and cracking times. The results will help understand how password complexity affects security and provide guidance to users on creating more secure passwords.
The document discusses how unprotected Windows file shares can expose systems to exploitation. Malicious software like the Klez worm, Nimda worm, and Sircam virus spread rapidly in 2001 by accessing unprotected shares. The document outlines techniques attackers use like scanning for systems with port 445 open and exploiting weak or null passwords. Examples of malware discussed are the W32/Deloder, GT-bot, and W32/Slackor worms which use these techniques to spread. The document recommends disabling unnecessary shares, using strong unique passwords, and keeping anti-virus software up to date to prevent exploitation.
A LIGHT WEIGHT SOLUTION FOR DETECTING DE-AUTHENTICATION ATTACK IJNSA Journal
Nowadays Wireless local area networks (WLANs) are growing very rapidly. Due to the popularity of 802.11 networks, possibilities of various attacks to the wireless network have also increased. In this paper, a special type of attack De-Authentication/disassociation attack has been investigated. In a normal scenario, a wireless client or user sends a de-authentication frame when it wants to terminate the connection. These frames are in plain text and are not encrypted. These are not authenticated by the access point. Attackers take advantage of this, and spoof these packets and disable the communication between the connected client and access point. In this paper, an algorithm based on radio-tap header information is suggested to identify whether there is a De-Authentication attack on the client or not.
Ethical hacking chapter 8 - Windows Vulnerabilities - Eric VanderburgEric Vanderburg
The document discusses tools for assessing vulnerabilities on Microsoft systems, including the Microsoft Baseline Security Analyzer (MBSA), Winfingerprint, and HFNetChk. It describes vulnerabilities in Microsoft operating systems and services like NetBIOS, SMB/CIFS, IIS, and SQL Server. The document provides best practices for securing Microsoft systems such as keeping systems patched, using antivirus software, enabling logging, and disabling unused services.
DoubleGuard is an intrusion detection system that models the network behavior of user sessions across both the front-end web server and back-end database to detect attacks that independent IDS's would miss, by monitoring both web requests and subsequent database queries; it was implemented using Apache, MySQL, and virtualization, and evaluated on real-world traffic over 15 days with 100% accuracy on static web apps and 0.6% false positives on dynamic apps.
DEH-DoSv6: A defendable security model against IPv6 extension headers denial ...journalBEEI
With the rapid depletion of IPv4 protocol in these recent years, the IETF introduced IPv6 as a solution to address the exhaustion, however, as a new protocol exists, new characteristics have been introduced and new threats have been discovered. Extension Headers are the new characteristics of IPv6 that have an emerging and re-emerging security threats that is needed to be taken into consideration during the full migration to the IPv6 network. This study revealed that up to this moment, the popular vendors are still vulnerable and doesn’t have any default protection to deal with extension headers’ Denial of Service Attack (DoS). Also, this study leads to the development of new security model which creates a new solution to address the emerging threats of IPv6 extension headers’ Denial of Service Attack. Moreover, the results of this study show that our proposed security model is more effective in terms of neutralizing the unwanted traffic causing evasion attack by filtering, rate-limiting and discarding the malformed packets of prohibited extension headers’ payload versus the traditional router protection.
Access control lists (ACLs) determine which devices can access routers based on IP address. ACLs can filter packets based on port numbers and are configured for inbound or outbound traffic. Standard ACLs filter based on source IP, while extended ACLs can filter based on additional attributes like protocol, ports, and IP addresses. Virtual private networks (VPNs) use protocols like IPSec and SSL with authentication methods such as certificates to securely transmit data over unsecured networks.
The document summarizes network security at the seven layers of the OSI model. It describes attacks that can occur at each layer, from the application layer down to the physical layer. It also lists some common countermeasures that can be implemented at each layer to enhance security, such as virus scanners, encryption protocols, access control systems, and virtual private networks. Overall, implementing additional security controls and limiting unnecessary access helps strengthen defenses across all layers of the OSI model.
The document discusses a three-tier architecture for web applications with clients, application servers, and databases. It proposes a system called Double Guard that uses lightweight virtualization to assign each user session to an isolated container. This allows Double Guard to build models of normal network behavior that capture the relationship between front-end web requests and back-end database queries, enabling it to detect attacks. The document outlines limitations of existing intrusion detection systems in multi-tier environments and the objectives of the Double Guard system.
Certified Ethical Hacker quick test prep cheat sheetDavid Sweigert
The document provides a list of technical terms and concepts related to cybersecurity. Some key points include: WPA2 supports AES encryption, Nmap can perform various scan types including protocol (-sO) and half open (-sS) scans, Cain & Abel can crack Cisco VPN passwords and record VoIP calls, IKE scan is used to fingerprint VPN servers, and stream ciphers are typically faster than block ciphers though encrypt smaller amounts of data at a time.
This document provides a summary of recent cybersecurity news and announcements from August and September 2011. It covers topics like announcements for security conferences Malcon 2011 and Nullcon 2012. It also discusses the DigiNotar certificate authority breach, the Comodohacker attack, doppelganger domains collecting email, the Morto RDP worm, Android mobile phone monitoring services, the Linux kernel source code breach, and new malware like Mebromi and Spyeyetrojan. It provides an overview of security tools like OWASP GoatDroid and updates to existing tools. Finally, it lists some security reading materials.
Implementation of public key cryptography in kerberos with prevention 2IAEME Publication
This document summarizes a research paper that proposes implementing public key cryptography in Kerberos to prevent security attacks like replay attacks and password attacks. The paper describes how Kerberos currently uses symmetric key cryptography, which is vulnerable to such attacks. It then outlines a new method using both RSA and Diffie-Hellman public key algorithms. The proposed method has authentication and ticket granting servers maintain databases containing users' public keys and passwords. When a client authenticates, tickets are encrypted using the client's public key instead of a symmetric key. This integration of public key cryptography is designed to strengthen Kerberos authentication against replay and password attacks.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document is a security glossary from Razorpoint Security Technologies containing definitions of common security, hacking, and technology terms. It was last updated on January 9, 2006 and contains copyright information. The glossary contains over 150 terms spanning operating systems, networks, and technologies to help people understand the latest security terminology. If the reader has any other terms they would like defined, they can contact Razorpoint Security.
Kerberos is a network authentication protocol that provides secure authentication for client/server applications. It uses secret-key cryptography and relies on a trusted third party called the Key Distribution Center (KDC) which is aware of all systems on the network. Kerberos introduces tickets that allow a client access to a server after initial authentication with the KDC. The authentication process involves the client receiving a ticket-granting ticket from the KDC and then exchanging messages with the ticket-granting service and target server to gain access.
Utilizing Data Mining Approches in the Detection of Intrusion in IPv6 Network...IDES Editor
The development of Internet protocols are greatly
needed as the network security becomes one of the most
important issues. This brings the need to develop IPv4 into
IPv6 in order to proceed towards increasing the network
capacity.
Now Intruders are considered as one of the most serious
threats to the internet security. Data mining techniques have
been successfully utilized in many applications. Many
research projects have applied data mining techniques to
intrusion detection. Furthermore different types of data
mining algorithms are very much useful to intrusion detection
such as Classification, Link Analysis and Sequence Analysis.
Moreover, one of the major challenges in securing fast
networks is the online detection of suspicious anomalies in
network traffic pattern. Most of the current security solutions
failed to perform the security task in online mode because of
the time needed to capture the packets and making decision
about it.
Practically, this study provides alliterative survey for the
enhancement associated with IPv6 in terms of its security
related functions. It is worthy mentioned that this study is
concurred with the data mining approaches that have been
used to detect intrusions.
Kerberos is an authentication system that uses symmetric cryptography to allow nodes on an insecure network to prove their identity to one another. It was developed at MIT to allow users to securely access services over the university's open computer network. Kerberos uses tickets and timestamps to authenticate users based on a variant of the Needham-Schroeder protocol while preventing replay attacks. The protocol relies on trusted central authentication servers and assumes all computers on the network could be compromised, so it aims to authenticate users rather than individual machines.
This document discusses the Kerberos authentication protocol. It provides a high-level overview of Kerberos, including its history, terminology, working, environment, database, and administrator. Kerberos provides strong authentication for physically insecure networks using trusted third parties and time-stamped tickets. While it ensures passwords are not sent in the clear, Kerberos is vulnerable if users choose poor passwords and relies on all machines being designed for its authentication.
This document provides a high-level overview of how Kerberos authentication works. It explains that Kerberos uses a trusted third party called the Key Distribution Center (KDC) to mediate authentication between users and services. The KDC distributes session keys to allow communication and verifies users' identities through cryptographic operations. It also describes how Kerberos implements single sign-on through the use of ticket-granting tickets obtained from the KDC. Some advantages of Kerberos include strong authentication without sending passwords over the network and more convenient single sign-on for users.
This document discusses adding public key cryptography to Kerberos to address limitations. It introduces three extensions: PKINIT for initial authentication using public keys; PKCROSS for cross-realm authentication using public keys between KDCs; and PKTAPP for authenticating to application servers using public keys. It analyzes performance and security issues when using these extensions and concludes they can improve Kerberos scalability in large networks.
Detecting co residency with active traffic analysis techniquesYama Haku
The document proposes and evaluates techniques for detecting whether virtual machines are co-located on the same physical host using active network traffic analysis. It introduces a method called "co-resident watermarking" that embeds signals in the network flow of a target virtual machine using small packet delays. Experimental results show this approach can accurately detect co-residency between VMs within 10 seconds by analyzing the watermarked network traffic patterns. The study also explores potential defenses and limitations of the detection techniques.
This document is the final honors project report submitted by Antony Law comparing the security of simple versus complex passwords when implemented in WLAN security frameworks WPA and WPA2. The project aims to evaluate the impact of password complexity on resistance to password cracking attacks. An experiment will be conducted using the aircrack-ng and oclHashcat password cracking tools against various simple and complex password scenarios to determine differences in success rates and cracking times. The results will help understand how password complexity affects security and provide guidance to users on creating more secure passwords.
The document discusses how unprotected Windows file shares can expose systems to exploitation. Malicious software like the Klez worm, Nimda worm, and Sircam virus spread rapidly in 2001 by accessing unprotected shares. The document outlines techniques attackers use like scanning for systems with port 445 open and exploiting weak or null passwords. Examples of malware discussed are the W32/Deloder, GT-bot, and W32/Slackor worms which use these techniques to spread. The document recommends disabling unnecessary shares, using strong unique passwords, and keeping anti-virus software up to date to prevent exploitation.
A LIGHT WEIGHT SOLUTION FOR DETECTING DE-AUTHENTICATION ATTACK IJNSA Journal
Nowadays Wireless local area networks (WLANs) are growing very rapidly. Due to the popularity of 802.11 networks, possibilities of various attacks to the wireless network have also increased. In this paper, a special type of attack De-Authentication/disassociation attack has been investigated. In a normal scenario, a wireless client or user sends a de-authentication frame when it wants to terminate the connection. These frames are in plain text and are not encrypted. These are not authenticated by the access point. Attackers take advantage of this, and spoof these packets and disable the communication between the connected client and access point. In this paper, an algorithm based on radio-tap header information is suggested to identify whether there is a De-Authentication attack on the client or not.
Ethical hacking chapter 8 - Windows Vulnerabilities - Eric VanderburgEric Vanderburg
The document discusses tools for assessing vulnerabilities on Microsoft systems, including the Microsoft Baseline Security Analyzer (MBSA), Winfingerprint, and HFNetChk. It describes vulnerabilities in Microsoft operating systems and services like NetBIOS, SMB/CIFS, IIS, and SQL Server. The document provides best practices for securing Microsoft systems such as keeping systems patched, using antivirus software, enabling logging, and disabling unused services.
DoubleGuard is an intrusion detection system that models the network behavior of user sessions across both the front-end web server and back-end database to detect attacks that independent IDS's would miss, by monitoring both web requests and subsequent database queries; it was implemented using Apache, MySQL, and virtualization, and evaluated on real-world traffic over 15 days with 100% accuracy on static web apps and 0.6% false positives on dynamic apps.
DEH-DoSv6: A defendable security model against IPv6 extension headers denial ...journalBEEI
With the rapid depletion of IPv4 protocol in these recent years, the IETF introduced IPv6 as a solution to address the exhaustion, however, as a new protocol exists, new characteristics have been introduced and new threats have been discovered. Extension Headers are the new characteristics of IPv6 that have an emerging and re-emerging security threats that is needed to be taken into consideration during the full migration to the IPv6 network. This study revealed that up to this moment, the popular vendors are still vulnerable and doesn’t have any default protection to deal with extension headers’ Denial of Service Attack (DoS). Also, this study leads to the development of new security model which creates a new solution to address the emerging threats of IPv6 extension headers’ Denial of Service Attack. Moreover, the results of this study show that our proposed security model is more effective in terms of neutralizing the unwanted traffic causing evasion attack by filtering, rate-limiting and discarding the malformed packets of prohibited extension headers’ payload versus the traditional router protection.
Access control lists (ACLs) determine which devices can access routers based on IP address. ACLs can filter packets based on port numbers and are configured for inbound or outbound traffic. Standard ACLs filter based on source IP, while extended ACLs can filter based on additional attributes like protocol, ports, and IP addresses. Virtual private networks (VPNs) use protocols like IPSec and SSL with authentication methods such as certificates to securely transmit data over unsecured networks.
The document summarizes network security at the seven layers of the OSI model. It describes attacks that can occur at each layer, from the application layer down to the physical layer. It also lists some common countermeasures that can be implemented at each layer to enhance security, such as virus scanners, encryption protocols, access control systems, and virtual private networks. Overall, implementing additional security controls and limiting unnecessary access helps strengthen defenses across all layers of the OSI model.
The document discusses a three-tier architecture for web applications with clients, application servers, and databases. It proposes a system called Double Guard that uses lightweight virtualization to assign each user session to an isolated container. This allows Double Guard to build models of normal network behavior that capture the relationship between front-end web requests and back-end database queries, enabling it to detect attacks. The document outlines limitations of existing intrusion detection systems in multi-tier environments and the objectives of the Double Guard system.
Certified Ethical Hacker quick test prep cheat sheetDavid Sweigert
The document provides a list of technical terms and concepts related to cybersecurity. Some key points include: WPA2 supports AES encryption, Nmap can perform various scan types including protocol (-sO) and half open (-sS) scans, Cain & Abel can crack Cisco VPN passwords and record VoIP calls, IKE scan is used to fingerprint VPN servers, and stream ciphers are typically faster than block ciphers though encrypt smaller amounts of data at a time.
This document provides a summary of recent cybersecurity news and announcements from August and September 2011. It covers topics like announcements for security conferences Malcon 2011 and Nullcon 2012. It also discusses the DigiNotar certificate authority breach, the Comodohacker attack, doppelganger domains collecting email, the Morto RDP worm, Android mobile phone monitoring services, the Linux kernel source code breach, and new malware like Mebromi and Spyeyetrojan. It provides an overview of security tools like OWASP GoatDroid and updates to existing tools. Finally, it lists some security reading materials.
Implementation of public key cryptography in kerberos with prevention 2IAEME Publication
This document summarizes a research paper that proposes implementing public key cryptography in Kerberos to prevent security attacks like replay attacks and password attacks. The paper describes how Kerberos currently uses symmetric key cryptography, which is vulnerable to such attacks. It then outlines a new method using both RSA and Diffie-Hellman public key algorithms. The proposed method has authentication and ticket granting servers maintain databases containing users' public keys and passwords. When a client authenticates, tickets are encrypted using the client's public key instead of a symmetric key. This integration of public key cryptography is designed to strengthen Kerberos authentication against replay and password attacks.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document is a security glossary from Razorpoint Security Technologies containing definitions of common security, hacking, and technology terms. It was last updated on January 9, 2006 and contains copyright information. The glossary contains over 150 terms spanning operating systems, networks, and technologies to help people understand the latest security terminology. If the reader has any other terms they would like defined, they can contact Razorpoint Security.
Kerberos is a network authentication protocol that provides secure authentication for client/server applications. It uses secret-key cryptography and relies on a trusted third party called the Key Distribution Center (KDC) which is aware of all systems on the network. Kerberos introduces tickets that allow a client access to a server after initial authentication with the KDC. The authentication process involves the client receiving a ticket-granting ticket from the KDC and then exchanging messages with the ticket-granting service and target server to gain access.
Utilizing Data Mining Approches in the Detection of Intrusion in IPv6 Network...IDES Editor
The development of Internet protocols are greatly
needed as the network security becomes one of the most
important issues. This brings the need to develop IPv4 into
IPv6 in order to proceed towards increasing the network
capacity.
Now Intruders are considered as one of the most serious
threats to the internet security. Data mining techniques have
been successfully utilized in many applications. Many
research projects have applied data mining techniques to
intrusion detection. Furthermore different types of data
mining algorithms are very much useful to intrusion detection
such as Classification, Link Analysis and Sequence Analysis.
Moreover, one of the major challenges in securing fast
networks is the online detection of suspicious anomalies in
network traffic pattern. Most of the current security solutions
failed to perform the security task in online mode because of
the time needed to capture the packets and making decision
about it.
Practically, this study provides alliterative survey for the
enhancement associated with IPv6 in terms of its security
related functions. It is worthy mentioned that this study is
concurred with the data mining approaches that have been
used to detect intrusions.
Kerberos is an authentication system that uses symmetric cryptography to allow nodes on an insecure network to prove their identity to one another. It was developed at MIT to allow users to securely access services over the university's open computer network. Kerberos uses tickets and timestamps to authenticate users based on a variant of the Needham-Schroeder protocol while preventing replay attacks. The protocol relies on trusted central authentication servers and assumes all computers on the network could be compromised, so it aims to authenticate users rather than individual machines.
This document discusses the Kerberos authentication protocol. It provides a high-level overview of Kerberos, including its history, terminology, working, environment, database, and administrator. Kerberos provides strong authentication for physically insecure networks using trusted third parties and time-stamped tickets. While it ensures passwords are not sent in the clear, Kerberos is vulnerable if users choose poor passwords and relies on all machines being designed for its authentication.
This document provides a high-level overview of how Kerberos authentication works. It explains that Kerberos uses a trusted third party called the Key Distribution Center (KDC) to mediate authentication between users and services. The KDC distributes session keys to allow communication and verifies users' identities through cryptographic operations. It also describes how Kerberos implements single sign-on through the use of ticket-granting tickets obtained from the KDC. Some advantages of Kerberos include strong authentication without sending passwords over the network and more convenient single sign-on for users.
This document discusses adding public key cryptography to Kerberos to address limitations. It introduces three extensions: PKINIT for initial authentication using public keys; PKCROSS for cross-realm authentication using public keys between KDCs; and PKTAPP for authenticating to application servers using public keys. It analyzes performance and security issues when using these extensions and concludes they can improve Kerberos scalability in large networks.
Kerberos Security in Distributed SystemsIRJET Journal
Kerberos is a network authentication protocol that provides single sign-on capabilities for client-server applications by allowing nodes communicating over a non-secure network to prove their identity to one another in a secure manner. It uses tickets and secret session keys to authenticate users and services. When a client wants to access a service, Kerberos issues it a ticket-granting ticket which it can use to obtain service tickets from the ticket granting service. These tickets contain encrypted proofs of the client's identity that can be verified by the service. Kerberos supports cross-realm authentication and uses shared symmetric keys and timestamps to securely authenticate users within distributed systems. While effective, it has some limitations such as increased computation load, single point of failure if the
Providing user security guarantees in public infrastructure cloudsKamal Spring
The infrastructure cloud (IaaS) service model offers improved resource flexibility and availability, where tenants – insulated from the minutiae of hardware maintenance – rent computing resources to deploy and operate complex systems. Large-scale services running on IaaS platforms demonstrate the viability of this model; nevertheless, many organizations operating on sensitive data avoid migrating operations to IaaS platforms due to security concerns. In this paper, we describe a framework for data and operation security in IaaS, consisting of protocols for a trusted launch of virtual machines and domain-based storage protection. We continue with an extensive theoretical analysis with proofs about protocol resistance against attacks in the defined threat model. The protocols allow trust to be established by remotely attesting host platform configuration prior to launching guest virtual machines and ensure confidentiality of data in remote storage, with encryption keys maintained outside of the IaaS domain. Presented experimental results demonstrate the validity and efficiency of the proposed protocols. The framework prototype was implemented on a test bed operating a public electronic health record system, showing that the proposed protocols can be integrated into existing cloud environments.
Kerberos is a Network Protocol that uses Secret - key cryptography to authenticate client - server applications. It provides the difference between the Firewall and kerberos. And also this slides are gives the information about how does the Kerberos works in ticket granting service and in Application server. Kerberos are work Within networks and small sets of networks.
Kerberos is a computer network authentication protocol which works on the basis of 'tickets' to allow
nodes communicating over a non-secure network to prove their identity to one another in a secure
manner. Its designers aimed it primarily at a client–server model and it provides mutual
authentication—both the user and the server verify each other's identity. Kerberos protocol messages
are protected against eavesdropping and replay attacks.
The infrastructure cloud (IaaS) service model offers improved resource flexibility and availability, where tenants – insulated from the minutiae of hardware maintenance – rent computing resources to deploy and operate complex systems. Large-scale services running on IaaS platforms demonstrate the viability of this model; nevertheless, many organizations operating on sensitive data avoid migrating operations to IaaS platforms due to security concerns. In this paper, we describe a framework for data and operation security in IaaS, consisting of protocols for a trusted launch of virtual machines and domain-based storage protection. We continue with an extensive theoretical analysis with proofs about protocol resistance against attacks in the defined threat model. The protocols allow trust to be established by remotely attesting host platform configuration prior to launching guest virtual machines and ensure confidentiality of data in remote storage, with encryption keys maintained outside of the IaaS domain. Presented experimental results demonstrate the validity and efficiency of the proposed protocols. The framework prototype was implemented on a test bed operating a public electronic health record system, showing that the proposed protocols can be integrated into existing cloud environments.
Key-exposure resistance has always been an important issue for in-depth cyber defence in many security applications. Recently, how to deal with the key exposure problem in the settings of cloud storage auditing has been proposed and studied. To address the challenge, existing solutions all require the client to update his secret keys in every time period, which may inevitably bring in new local burdens to the client, especially those with limited computation resources such as mobile phones. In this paper, we focus on how to make the key updates as transparent as possible for the client and propose a new paradigm called cloud storage auditing with verifiable outsourcing of key updates. In this paradigm, key updates can be safely outsourced to some authorized party, and thus the key-update burden on the client will be kept minimal. Specifically, we leverage the third party auditor (TPA) in many existing public auditing designs, let it play the role of authorized party in our case, and make it in charge of both the storage auditing and the secure key updates for key-exposure resistance. In our design, TPA only needs to hold an encrypted version of the client’s secret key, while doing all these burdensome tasks on behalf of the client. The client only needs to download the encrypted secret key from the TPA when uploading new files to cloud. Besides, our design also equips the client with capability to further verify the validity of the encrypted secret keys provided by TPA. All these salient features are carefully designed to make the whole auditing procedure with key exposure resistance as transparent as possible for the client. We formalize the definition and the security model of this paradigm. The security proof and the performance simulation show that our detailed design instantiations are secure and efficient.
This document discusses security enhancements for IEEE 802.11i wireless networks. It proposes using physical layer information and channel-based secrets to improve authentication and key establishment. Specifically, it suggests modifying the 802.11i key derivation process to incorporate information-theoretic secure bits extracted from wireless channel measurements. This would make stolen credentials like passwords less useful, improving security. The document outlines integrating channel secrets into the pairwise transient key derivation in 802.11i to provide forward and backward secrecy.
Protecting location privacy in sensor networks against a global eavesdropperShakas Technologies
The document discusses techniques for providing location privacy in sensor networks against a global eavesdropper. It proposes four techniques - periodic collection, source simulation, sink simulation, and backbone flooding - to provide location privacy for monitored objects (source location privacy) and data sinks (sink location privacy). These techniques provide trade-offs between privacy, communication cost, and latency. Analysis and simulation demonstrate that the proposed techniques are efficient and effective for providing source and sink location privacy in sensor networks.
Welcome to the world of 'network security' which is an unavoidable term in cyber security. This white paper of Network security encompasses the most significant and predominantly used networking security concepts which are highly important for maintaining your network environment secure.
AUTHENTICATION MECHANISM ENHANCEMENT UTILISING SECURE REPOSITORY FOR PASSWORD...IJNSA Journal
In this paper the idea of an enhanced security authentication procedure is presented. This procedure prohibits the transmission of the user’s password over the network while still providing the same authentication service. To achieve that, Kerberos Protocol and a secure password repository are adopted, namely a smart card. The conditional access to a smart card system provides a secure place to keep
credentials safe. Then, by referencing to them through identifiers, an authentication system may perform its
scope without revealing the secrets at all. This elevates the trustworthiness of the mechanism while at the same time it achieves to reduce the overhead of the authentication systems due to the elaborate encryptions procedures.
The document discusses wireless network security and WPA2-PSK. It covers the need for wireless security, early security protocols like WEP and their vulnerabilities. It then describes WPA and WPA2, how they work and their advantages over WEP. WPA2 uses the strong AES encryption algorithm. The document also discusses security threats to wireless networks like eavesdropping, man-in-the-middle attacks. While WPA2 is secure, it has some vulnerabilities in management frames and attacks like deauthentication. The proposed IEEE 802.11w standard aims to provide stronger protections against these vulnerabilities.
This document summarizes various data encryption techniques for securing data in cloud computing. It discusses hybrid encryption algorithms that combine Caesar cipher, RSA, and monoalphabetic substitution. It also describes the DES algorithm and its structure. Finally, it explores identity-based encryption (IBE) where a third party generates public keys based on user identifiers like email addresses. The document concludes that data security is an important issue for cloud computing and more research is still needed to enhance security features using cryptographic techniques.
Kubernetes Ransomware Threat - How to Protect and Recover.pdfUrolime Technologies
Kubernetes is becoming increasingly popular for automating large-scale software deployment, distribution, and management in a containerized environment. However, many Kubernetes Consulting companies view the threat of ransomware attacks as a barrier to ransomware adoption.
IRJET- Cryptography Encryption and Decryption File Protection based on Mo...IRJET Journal
This document discusses encryption and decryption techniques using Bluetooth proximity on mobile devices. It begins with an abstract that outlines using an encryption algorithm to convert meaningful file information into unintelligible data that cannot be read without decrypting. The encryption key would be the Bluetooth MAC address of a registered device.
The introduction explains using AES encryption to encode files into unreadable data, with the Bluetooth MAC address as the decryption key. It also discusses how encryption provides data security for wireless communication.
The document then reviews cryptography purposes like authentication and confidentiality. It examines symmetric key cryptography using the same key for encryption and decryption, and public key cryptography using different keys. It also defines plain text, cipher text, and encryption/
This document provides a summary of 18 rulemaking projects being undertaken by the Federal Aviation Administration (FAA). The projects cover topics such as digital flight data recorder regulations for Boeing 737s, aging aircraft programs, flight rules for the Washington D.C. area, repair station regulations, security considerations for airplane design, and congestion management rules for airports like LaGuardia. Each project summary includes the popular title, regulation identification number, current stage of rulemaking, docket information, abstract of the rulemaking, potential effects, and status of completing the final rule.
This document provides an introduction and overview of 5G technology. It discusses the evolution of mobile technologies from 1G to 5G networks. Key points include:
- 5G is the next major phase of mobile telecommunications following 4G LTE networks and will provide faster speeds, lower latency, and better connectivity.
- Previous generations included 1G (analog voice-only), 2G (digital voice and basic data), 3G (broadband data and internet access), and 4G (high-speed data for mobile internet).
- 5G aims to offer significantly higher minimum speeds (20Gbps+), extreme connectivity for billions of connected devices, and cutting edge applications like autonomous vehicles, telemedicine,
This document describes a proposed mobile virtual reality service (VRS) that would allow users to access real-time sights and sounds of physical environments virtually through mobile devices and networks. It outlines the key components needed for a VRS, including actual physical environments, VRS user equipment, a VRS access system, and a VRS core system for controlling VRS episodes. Challenges to implementing a VRS include needing very high data transmission rates for streaming video and audio, sophisticated user equipment, and an efficient signaling and control network. The document proposes an architecture and entities for a VRS core network, including a VRS episode control entity, VRS episode management entity, and gateway entity to facilitate VRS episode setup and control
The document summarizes a seminar report on Brain Gates. It describes how Brain Gates were developed by Cyberkinetics in 2003 to help people with disabilities control devices using only their brain activity. The Brain Gate system consists of a sensor implanted in the motor cortex that detects brain signals, which are then translated by a computer into cursor movements or control of other devices. Currently two patients have been implanted with Brain Gates, which use 100 electrodes to monitor brain activity related to intended limb movements and allow control of a computer cursor.
This document provides a 3-page summary of a seminar report on non-contact heart rate measurement using photoplethysmography. It begins with an introduction describing the motivation and challenges of non-contact heart rate measurement. It then provides background on topics such as resting heart rate measurement, photoplethysmography, and the use of blind source separation to remove motion artifacts. The experimental setup used a basic webcam to record videos of faces that were then analyzed to compute heart rate measurements in a non-contact manner.
This document provides information about digital scent technology, including its history, principles, hardware devices, applications, and limitations. It discusses how digital scent works, with hardware devices like the iSmell connecting to computers to emit smells from cartridges containing 128 chemicals. Applications mentioned include enhancing virtual reality experiences for movies, games, and online shopping. While the technology enhances multimedia, the summary notes it also faces limitations like rapid human acclimation to scents.
This document provides information about surface computing. It discusses Microsoft Surface, a large multi-touch tabletop computer that allows multiple users to interact directly on its screen surface using hands, brushes or other objects. Key features of surface computing include multi-touch interaction, tangible user interfaces using physical objects, support for multiple simultaneous users, and object recognition capabilities. The document also outlines the hardware components of Microsoft Surface and provides examples of its applications.
Project Loon is Google's initiative to provide internet access using high-altitude balloons. Balloons travel in the stratosphere and are arranged to form a communications network between 10-60km altitude. They are carried by wind currents and can be steered to different altitudes with different wind directions. People on the ground connect to the balloon network using a special antenna. The signal bounces between balloons and then back to earth, providing internet access over a 40km diameter area comparable to 3G speeds. Each balloon is made of a polyethylene envelope that houses solar panels and communications equipment to power the balloon and connect it to the network.
The document describes a technical seminar report on a smart note taker device, including an overview of the system and its construction, current products like mobile and PC note takers as well as smart pens, the technologies used including display and handwriting recognition, advantages and disadvantages, applications, future scope, and conclusions. It provides details on the interior structure and technical requirements and includes diagrams of the smart note taker system and current products.
The document discusses security improvements for ATMs. It proposes integrating facial recognition and iris scanning technologies into the identity verification process used by ATMs. This would help protect against fraud from stolen cards and PINs. The system would match a live image to an image stored in the bank's database associated with the account. Only a match between the images and correct PIN would verify the user. The document also discusses using iris scanning instead of cards and PINs for a cardless, password-free way to withdraw money by matching a scanned iris to images in the database. It suggests this biometric authentication could improve security over current magnetic card and PIN verification methods.
This document provides an overview of optical computing. Some key points:
- Optical computing uses light instead of electrons for computations and can process data much
faster than traditional electronic computers. An optical desktop computer is capable of processing
data 100,000 times faster.
- Important optical components that enable optical computing include vertical cavity surface emitting
lasers, spatial light modulators, smart pixel technology, and wavelength division multiplexing.
- Nonlinear optical materials play a significant role by interacting with light and modulating its
properties, enabling functions like optical logic gates. However, current materials have low efficiency.
- Optical computing was researched in the 1980s but progress slowed due
Project Ara is a modular smartphone platform developed by Google that allows users to customize their phone by swapping modules. The platform includes an endoskeleton frame that holds interchangeable modules for functions like display, camera, battery. This modularity provides longer usage by allowing users to replace broken modules or upgrade individual parts. The first developer version is scheduled for late 2016 with a basic phone costing around $50. Success depends on a vibrant ecosystem of third-party developed modules.
The document summarizes Rolls-Royce's Vision Next 100 concept vehicle. Key points:
- It is a fully autonomous, electric vehicle with no steering wheel and virtual assistant named Eleanor.
- The interior is a luxurious lounge-like space with seats resembling a couch.
- The vehicle is a concept of Rolls-Royce's vision for autonomous luxury mobility in the future, embracing new technologies while retaining the brand's focus on customization and coachbuilding.
This document provides an overview of iTwin technology, which allows users to securely access and share files between two computers using paired hardware devices. It describes how to install the iTwin software, set up a private VPN to access files and networks remotely, and troubleshoot any issues. Security features like remote disabling and passwords are also summarized to prevent unauthorized access to files or networks if one of the paired devices is lost.
The document provides information on QR codes, including their history, structure, capabilities, and generation. It discusses how QR codes can store more data than traditional barcodes, in a smaller space, and how their error correction allows them to be read even if dirty or damaged. The document also describes the key components of a QR code, such as finder patterns, alignment patterns, and data areas, and explains how QR codes are encoded with different data types.
The Emo Spark is a 90mm cube that uses artificial intelligence to interact with users based on their emotions. It can detect emotions like joy, sadness, trust and more using face tracking and content analysis. Over time, it builds an emotional profile graph of each user to better understand their preferences. The cube can communicate through conversation, play music and videos tailored to the user's emotions. It has various hardware components like a CPU, memory and custom emotion processing unit. The cube can connect to other devices and share media with other cubes based on similar emotional profiles. It aims to enhance how users experience media like music by understanding their emotional responses.
The document summarizes a technical seminar report on Apple iBeacon technology presented by D. Madhavi. It discusses how Apple created iBeacons using Bluetooth low-energy technology to allow companies to interact with customers using their smart devices within close proximity. Locally placed beacons can send messages to phones if the user has the company's app installed and Bluetooth turned on. The report also covers how beacons work, their battery life, compatible devices, applications, advantages and disadvantages of using beacon technology.
Sixth Sense technology allows users to access digital information about objects and surfaces in the physical world using hand gestures. It consists of a camera, projector, and mirror connected to a mobile device. The camera recognizes hand gestures and objects, and the projector displays additional digital information onto physical surfaces based on the camera's input. Some examples of uses include getting information about books by gesturing near them, checking flight statuses by gesturing over boarding passes, and making calls or accessing maps with hand gestures in the air. The technology aims to more seamlessly integrate digital information into everyday life using natural hand motions.
Android 5.0 Lollipop introduced major changes including a redesigned user interface called "material design" and improvements to notifications, battery life, security, and device sharing. It also improved performance through the new Android Runtime replacing Dalvik, added new connectivity and media features, and supported devices like Android TV. Lollipop aimed to provide a more consistent experience across different Android devices through its visual and functional changes.
The document describes Blue Eyes technology, which aims to give computers human-like perceptual abilities such as facial recognition, speech recognition, and emotion detection. It discusses the system overview including hardware and software components. Specifically, it explains how the system uses sensors to monitor users' physiological signals and detect their emotions in order to understand how they are interacting with the computer.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
Climate Impact of Software Testing at Nordic Testing DaysKari Kakkonen
My slides at Nordic Testing Days 6.6.2024
Climate impact / sustainability of software testing discussed on the talk. ICT and testing must carry their part of global responsibility to help with the climat warming. We can minimize the carbon footprint but we can also have a carbon handprint, a positive impact on the climate. Quality characteristics can be added with sustainability, and then measured continuously. Test environments can be used less, and in smaller scale and on demand. Test techniques can be used in optimizing or minimizing number of tests. Test automation can be used to speed up testing.
“An Outlook of the Ongoing and Future Relationship between Blockchain Technologies and Process-aware Information Systems.” Invited talk at the joint workshop on Blockchain for Information Systems (BC4IS) and Blockchain for Trusted Data Sharing (B4TDS), co-located with with the 36th International Conference on Advanced Information Systems Engineering (CAiSE), 3 June 2024, Limassol, Cyprus.
Dr. Sean Tan, Head of Data Science, Changi Airport Group
Discover how Changi Airport Group (CAG) leverages graph technologies and generative AI to revolutionize their search capabilities. This session delves into the unique search needs of CAG’s diverse passengers and customers, showcasing how graph data structures enhance the accuracy and relevance of AI-generated search results, mitigating the risk of “hallucinations” and improving the overall customer journey.
UiPath Test Automation using UiPath Test Suite series, part 5DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 5. In this session, we will cover CI/CD with devops.
Topics covered:
CI/CD with in UiPath
End-to-end overview of CI/CD pipeline with Azure devops
Speaker:
Lyndsey Byblow, Test Suite Sales Engineer @ UiPath, Inc.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
Programming Foundation Models with DSPy - Meetup SlidesZilliz
Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
Unlocking Productivity: Leveraging the Potential of Copilot in Microsoft 365, a presentation by Christoforos Vlachos, Senior Solutions Manager – Modern Workplace, Uni Systems
AI 101: An Introduction to the Basics and Impact of Artificial IntelligenceIndexBug
Imagine a world where machines not only perform tasks but also learn, adapt, and make decisions. This is the promise of Artificial Intelligence (AI), a technology that's not just enhancing our lives but revolutionizing entire industries.
Why You Should Replace Windows 11 with Nitrux Linux 3.5.0 for enhanced perfor...SOFTTECHHUB
The choice of an operating system plays a pivotal role in shaping our computing experience. For decades, Microsoft's Windows has dominated the market, offering a familiar and widely adopted platform for personal and professional use. However, as technological advancements continue to push the boundaries of innovation, alternative operating systems have emerged, challenging the status quo and offering users a fresh perspective on computing.
One such alternative that has garnered significant attention and acclaim is Nitrux Linux 3.5.0, a sleek, powerful, and user-friendly Linux distribution that promises to redefine the way we interact with our devices. With its focus on performance, security, and customization, Nitrux Linux presents a compelling case for those seeking to break free from the constraints of proprietary software and embrace the freedom and flexibility of open-source computing.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
UiPath Test Automation using UiPath Test Suite series, part 6DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Infrastructure Challenges in Scaling RAG with Custom AI modelsZilliz
Building Retrieval-Augmented Generation (RAG) systems with open-source and custom AI models is a complex task. This talk explores the challenges in productionizing RAG systems, including retrieval performance, response synthesis, and evaluation. We’ll discuss how to leverage open-source models like text embeddings, language models, and custom fine-tuned models to enhance RAG performance. Additionally, we’ll cover how BentoML can help orchestrate and scale these AI components efficiently, ensuring seamless deployment and management of RAG systems in the cloud.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
Threats to mobile devices are more prevalent and increasing in scope and complexity. Users of mobile devices desire to take full advantage of the features
available on those devices, but many of the features provide convenience and capability but sacrifice security. This best practices guide outlines steps the users can take to better protect personal devices and information.
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
Building Production Ready Search Pipelines with Spark and Milvus
14 577
1. 1
A seminar report on
KERBEROS
BY
K.RAJA GANGADHAR
14A81A0577
(Under the guidance of MR.J.VIJITHANAND, M.TECH)
DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
SRI VASAVI ENGINEERING COLLEGE
Pedatadepalli, Tadepalligudem-534101,
W.G.Dist, AndhraPradesh,
2016 - 17
2. 2
ABSTRACT
The Kerberos Authentication Service, developed by the Massachusetts Institute of
Technology (MIT). It was developed to enable network applications to securely identify their
peers across an insecure network and to protect the privacy and integrity of communication
with those services. Based on Needham-Schroeder-Protocol versions 1-3 of Kerberos were
only internal releases and never made public. While version 4 was a step up from traditional
security in networked systems, although v4 has its security flaws and extensions were needed
to allow its wide applications in environments with different characteristics than that at MIT.
This paper will show our more detailed specifications taking into account encryption types,
flags and options, error messages and a few timestamps analyzing Kerberos 5(1.10.3) which
is the latest release.
3. 3
INDEX
Contents Page No.
1. Introduction 1
1.1 What is Kerberos? 1
1.2 What are the Goals? 2
1.3 Evolution 2
2. Pieces of Puzzles 5
2.1 Privacy and integrity 6
2.2 Kerberos Terminology and Concepts 6
3. Protocols 9
3.1 Kerberos 4 9
3.2 Kerberos 5 10
3.3 Kerberos 5-to-4 Ticket Translation 12
4. Troubleshooting 14
4.1 Error and Solutions 14
5. Security 15
5.1Kerberos Attacks 15
5.2 Other Attacks 16
5.3 Protocol Security Issues 17
5.4 Security Solutions 19
6. Applications 20
6.1 Services and Keytabs 20
6.2 Transparent Kerberos Login with PAM 20
6.3 Mac OS X and the login Window 21
7. Advance Topic 22
7.1 Using Kerberos 4 Services with Kerberos 5 22
8. Kerberos Future 23
8.1Smart Cards 23
8.2 Better Encryption 23
8.3Kerberos Referrals 24
8.4Web Services 25
9. References 27
4. 4
LIST OF FIGURES
Figure Name Page No.
Figure 1: AS_REQ and AS_REP exchange 9
Figure 2: Encryption types in a typical TGS reply 11
Figure 3: Kerberos replay attack 18
5. 5
1. INTRODUCTION
1.1 What is Kerberos? :
Kerberos is a secure method for authenticating a request for a service in a computer
network. Kerberos was developed in the Athena Project at the Massachusetts Institute of
Technology (MIT). The name is taken from Greek mythology; Kerberos was a three-headed
dog who guarded the gates of Hades. Kerberos lets a user request an encrypted "ticket" from
an authentication process that can then be used to request a particular service from a server.
The user's password does not have to pass through the network. A version of Kerberos (client
and server) can be downloaded from MIT or you can buy a commercial version.
1.1.1 Advantages of Kerberos:
Most conventional network services use password-based authentication schemes.
Such schemes require a user to authenticate to a given network server by supplying their
username and password. Unfortunately, the transmission of authentication information for
many services is unencrypted. For such a scheme to be secure, the network has to be
inaccessible to outsiders, and all computers and users on the network must be trusted and
trustworthy.
Even if this is the case, a network that is connected to the Internet can no longer be
assumed to be secure. Any attacker who gains access to the network can use a simple packet
analyzer, also known as a packet sniffer, to intercept usernames and passwords,
compromising user accounts and the integrity of the entire security infrastructure.
1.1.2 Disadvantages of Kerberos:
Although Kerberos removes a common and severe security threat, it may be difficult
to implement for a variety of reasons:
Migrating user passwords from a standard UNIX password database, such as
/etc/passwd or /etc/shadow, to a Kerberos password database can be tedious, as there is no
automated mechanism to perform this task. Refer to Question 2.23 in the online Kerberos.
6. 6
Kerberos has only partial compatibility with the Pluggable Authentication Modules (PAM)
system used by most Red Hat Enterprise Linux servers. Refer to Section 42.6.4, “Kerberos
and PAM” for more information about this issue.
Kerberos assumes that each user is trusted but is using an untrusted host on an
untrusted network. Its primary goal is to prevent unencrypted passwords from being
transmitted across that network. However, if anyone other than the proper user has access to
the one host that issues tickets used for authentication — called the key distribution center
(KDC) — the entire Kerberos authentication system is at risk.
For an application to use Kerberos, its source must be modified to make the
appropriate calls into the Kerberos libraries. Applications modified in this way are considered
to be Kerberos-aware, or kerberized. For some applications, this can be quite problematic due
to the size of the application or its design. For other incompatible applications, changes must
be made to the way in which the server and client communicate. Again, this may require
extensive programming. Closed-source applications that do not have Kerberos support by
default are often the most problematic.
Kerberos is an all-or-nothing solution. If Kerberos is used on the network, any
unencrypted passwords transferred to a non-Kerberos aware service is at risk. Thus, the
network gains no benefit from the use of Kerberos. To secure a network with Kerberos, one
must either use Kerberos-aware versions of all client/server applications that transmit
passwords unencrypted, or not use any such client/server applications at all.
1.2 What are the Goals? :
The primary design goal of Kerberos is to eliminate the transmission of unencrypted
passwords across the network. If used properly, Kerberos effectively eliminates the threat that
packet sniffers would otherwise pose on a network.
1.3 Evolution of Kerberos:
1.3.1 Early Kerberos (v1, v2, v3):
The early versions of Kerberos (pre-Version 4) were created and used internally at
MIT for testing purposes. These implementations contained significant limitations and were
7. 7
only useful to examine new ideas and observe the practical issues that arose during
development and testing.
1.3.2 Kerberos 4:
The first version of Kerberos distributed outside of MIT was Kerberos 4. First
released to the public on January 24, 1989, Kerberos 4 was adopted by several vendors, who
included it in their operating systems. In addition, other, large distributed software projects
such as the Andrew File System adopted the concepts behind Kerberos 4 for their own
authentication mechanisms.The basics of what was to become the Kerberos 4 protocol are
documented in the Athena Technical Plan. Ultimately, the details of the protocol were
documented through the source code in the reference implementation published by MIT.
However, due to export control restrictions on encryption software imposed by the
U.S. government, Kerberos 4 could not be exported outside of the United States. Since
Kerberos 4 uses DES encryption, organizations outside of the U.S. could not legally
download the Kerberos 4 software as-is from MIT. In response, the MIT development team
stripped all of the encryption code from Kerberos 4 to create a specialized, exportable
version. Eric Young, at Bond University of Australia, took this stripped version of Kerberos 4
and added his own implementation of DES to create "eBones.” Since eBones contained
encryption software developed outside of the United States, it was unencumbered by the U.S.
encryption export controls, and could be legally used anywhere in the world.
Today, several implementations of Kerberos 4 still exist. The original MIT Kerberos 4
implementation is now in a maintenance mode and officially considered “dead.” The kth-krb
distribution, developed in Sweden, is still actively developed but it is highly recommended
that new installations use the superior Kerberos 5 instead. In this book, coverage of Kerberos
4 is restricted to a discussion of the protocol in Chapter 3. Most of the book covers the next
version of Kerberos, Kerberos 5.
1.3.3 Kerberos 5:
Kerberos 5 was developed to add features and security enhancements that were not
present in Version 4 of the protocol. Kerberos 5 is the latest version of the Kerberos protocol
and is documented in RFC 1510.
8. 8
To correct the deficiencies in the Kerberos 4 protocol, several new features were added. They
include:
A better wire protocol, based on ASN.1
Credential forwarding and delegation
Replay cache
More flexible cross-realm authentication
Extensible encryption types
Pre-authentication
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2. PIECES OF PUZZLES
2.1 Privacy and Integrity:
Authentication is the verification of the identity of a party who generated some data,
and of the integrity of the data. A principal is the party whose identity is verified. The verifier
is the party who demands assurance of the principal's identity. Data integrity is the assurance
that the data received is the same as generated. Authentication mechanisms differ in the
assurances they provide: some indicate that data was generated by the principal at some point
in the past, a few indicate that the principal was present when the data was sent, and others
indicate that the data received was freshly generated by the principal. Mechanisms also differ
in the number of verifiers: some support a single verifier per message, while others support
multiple verifiers. A third difference is whether the mechanism supports non-repudiation, the
ability of the verifier to prove to a third party that the message originated with the principal.
Because these differences affect performance, it is important to understand the
requirements of an application when choosing a method. For example, authentication for
electronic mail may require support for multiple recipients and non-repudiation, but can
tolerate greater latency. In contrast, poor performance would cause problems for
authentication to a server responding to frequent queries.
Other security services include confidentiality and authorization. Confidentiality is the
protection of information from disclosure to those not intended to receive it. Most strong
authentication methods optionally provide confidentiality. Authorization is the process by
which one determines whether a principal is allowed to perform an operation. Authorization
is usually performed after the principal has been authenticated, and may be based on
information local to the verifier, or based on authenticated statements by others.
The remainder of this article will concentrate on authentication for real-time,
interactive services that are offered on computer networks. We use the term real-time loosely
to mean that a client process is waiting for a response to a query or command so that it can
display the results to the user, or otherwise continue performing its intended function. This
class of services includes remote login, file system reads and writes, and information retrieval
for applications like Mosaic.
10. 10
2.1 Why Kerberos:
The introduction discussed the problems associated with password based
authentication and, in particular, how passwords can be collected by eavesdropping. In
addition to the security concern, password based authentication is inconvenient; users do not
want to enter a password each time they access a network service. This has led to the use of
even weaker authentication on computer networks: authentication by assertion.
While more convenient for the user, authentication by assertion hardly qualifies as
authentication at all. Examples include the Berkeley R-command suite and the IDENT
protocol. With authentication by assertion, applications assert the identity of the user and the
server believes it. Such authentication is easily thwarted by modifying the application. This
may require privileged access to the system, which is easily obtained on PCs and personal
workstations. While most uses of authentication by assertion require that a connection
originate from a ``trusted'' network address, on many networks, addresses are themselves
simply assertions.
Stronger authentication methods base on cryptography are required. When using
authentication based on cryptography, an attacker listening to the network gains no
information that would enable it to falsely claim another's identity. Kerberos is the most
commonly used example of this type of authentication technology. Unfortunately, strong
authentication technologies are not used as often as they should be, although the situation is
gradually improving.
2.2 Kerberos Terminology and Concepts:
2.2.1 Kerberos-Specific Terminology:
You need to understand the terms in this section in order to administer KDCs. The
Key Distribution Center or KDC is the component of Kerberos that is responsible for issuing
credentials. These credentials are created by using information that is stored in the KDC
database. Each realm needs at least two KDCs, a master and at least one slave. All KDCs
generate credentials, but only the master KDC handles any changes to the KDC database.
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A stash file contains the master key for the KDC. This key is used when a server is
rebooted to automatically authenticate the KDC before starting the Kadin and krb5kdc
commands. Because this file includes the master key, the file and any backups of the file
should be kept secure. The file is created with read-only permissions for root. To keep the file
secure, do not change the permissions. If the file is compromised, then the key could be used
to access or modify the KDC database.
2.2.2. Authentication-Specific Terminology:
You need to know the terms in this section to understand the authentication process.
Programmers and system administrators should be familiar with these terms.A client is the
software that runs on a user's workstation. The Kerberos software that runs on the client
makes many requests during this process. So, differentiating the actions of this software from
the user is important.
The terms server and service are often used interchangeably. To clarify, the term
server is used to define the physical system that Kerberos software is running on. The term
service corresponds to a particular function that is being supported on a server (for example,
ftp or n’s). Documentation often mentions servers as part of a service, but this definition
clouds the meaning of the terms. Therefore, the term server refers to the physical system. The
term service refers to the software.
The Kerberos product uses two types of keys. One type of key is a password derived
key. The password derived key is given to each user principal and is known only to the user
and to the KDC. The other type of key used by the Kerberos product is a random key that is
not associated with a password and so is not suitable for use by user principals. Random keys
are typically used for service principals that have entries in a keytab and session keys
generated by the KDC. Service principals can use random keys since the service can access
the key in the keytab which allows it to run non-interactively. Session keys are generated by
the KDC (and shared between the client and service) to provide secure transactions between a
client and a service.
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A ticket is an information packet that is used to securely pass the identity of a user to
a server or service. A ticket is valid for only a single client and a particular service on a
specific server. A ticket contains:
Principal name of the service
Principal name of the user
IP address of the user's host
Timestamp
Value which defines the lifetime of the ticket
Copy of the session key
All of this data is encrypted in the server's service key. Note, the KDC issues the ticket
embedded in a credential described below. After a ticket has been issued, it can be reused
until the ticket expires.A credential is a packet of information that includes a ticket and a
matching session key. The credential is encrypted with the requesting principal's key.
Typically, the KDC generates a credential in response to a ticket request from a client.
An authenticator is information used by the server to authenticate the client user principal.
An authenticator includes the principal name of the user, a timestamp, and other data. Unlike
a ticket, an authenticator can be used once only, usually when access to a service is requested.
An authenticator is encrypted by using the session key shared by the client and server.
Typically, the client creates the authenticator and sends it with the server's or service's ticket
in order to authenticate to the server or service.
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3. PROTOCOLS
3.1 Kerberos 4:
The base of Kerberos protocol is Needham-Schroeder protocol. There are only two
differences between the two protocols. These two differences are shown below
1. The hosts present in the Kerberos 4 protocol do exchange of mapping directly that is
present in the Needham-Schroeder protocol.
2. The authentication client is a Kerberos 4 user workstation, and the authentication
server maps to a Kerberos 4 Key Distribution Center.
The following figure shows the AS_REQ and AS_REP of the protocols
Figure 1: AS_REQ and AS_REP exchange
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3.2 Kerberos 5:
Kerberos 5 is evolved from Kerberos 4. It has all the functions that Kerberos 4 has in
its functionality. But also there are few differences and extensions. The Kerberos 4 protocol
had some drawbacks in its structure that it has may be an obtuse structure and it was not
capable of expanding as many of the fields have fixed and defined sizes. These limitations
create some problems most notably the dependence on single-DES encryption keys. When
Kerberos was invented there was a brute-force attack was made on DES that was
prohibitively expensive in terms of both resources and time. So it is necessary for the
presence of such brute force as the speed of computer during its function. Hence it is needed
to have a larger encrypted algorithm with larger encryption key. It is unfortunately not
possible to increment the size of Kerberos 4 so there is no way for retrofit.
Although in Kerberos 5 protocol is still under development process. Its main features
are given below
3.2.1 New Encryption Options:
This option indicates that for a single protocol transaction there could be either one or
type of encryptions present. Even in the following messages separate encryptions can be
used.
Ticket:
The encryption associated with is used to encrypt the ticket in the TGS or AS reply.
Since the ticket can only be decrypted by the service, as it is encrypted with the service’s
encryption key, the type of encryption made on the ticket is determined by the highest
encryption that is supported by the service for particular ticket.
Reply:
The encryption type of the reply from the KDC to the client refers to the part of the
reply encrypted with the user’s encryption key. Since the ticket can only be decrypted by the
client support, as it is encrypted with the client support encryption key, the type of encryption
made on the ticket is determined by the highest encryption that is supported by the client
support for particular ticket.
15. 15
Session key:
This key is a sharing between the client and the server so here needed to have that
type of encryption key that is supported by both client support and service.
For example, if the client supports single and triple DES but the service only supports
single DES, then the KDC will issue single DES session keys for this service.
A diagram showing where each encryption key comes into play in a typical TGS
reply is shown in below.
Figure 2: Encryption types in a typical TGS reply
A fine gained control is enabled if all the three parties have at least one type of
encryption in common. When KDC is used to create a, it normally make a storage of its
encryption key using all of the different encryption types that it supports. Therefore, the most
secure encryption type that is supported by all the three parties is given out by KDC.
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3.2.2 Ticket Options:
Kerberos 5 includes advanced features that allow users more control over their
Kerberos tickets.
The following flags have been added to Kerberos 5:
Forward able tickets:
A user can request a forward able ticket. A forward able ticket can be given to another
host later. After that the ticket and the ticket name are used by the new host. A common
special case is the forward able Ticket Granting Ticket.
Proxiable tickets:
It is also possible to set the proxiable flag on a ticket.like forward able tickets they can
also be transferred to other host. However, a proxiable TGT can only be used to acquire
further service tickets; it cannot be used to acquire a new TGT on the target host.
Renewable tickets:
Kerberos 5 introduces a two-tiered life time scheme. The scheme gets the benefits of
longer lifetimes with the security of shorter lifetimes.
For example, if a user needs a renewable ticket he is issued by a ticket having a
standard lifetime and a renewable lifetime. The ticket is valid only for the duration of the
standard lifetime, but can be submitted back to the KDC for renewal any time before the
ticket expires (at the end of the standard lifetime). The KDC can refuse to validate the ticket.
Postdated tickets:
It is a special type of ticket which is not valid until some specified date in the future.
It will be refused if a postdated ticket is presented for validation before the start date
embedded in the ticket
3.3 Kerberos 5-to-4 Ticket Translation:
To show some similarity with older Kerberos 4 services, Kerberos 5 provides with a
service, knows as Kerberos 5-to-4 ticket translation service. This service is also called
17. 17
krb524. It gives you an opportunity that the clients of Kerberos version 5 can interact with the
previous Kerberos version 4 services, but it does not provide the clients of Kerberos version 4
a way to interact with Kerberos 5 services or KDCs.
When a Kerberos 5 client wants to develop a connection to service that is only
understandable by Kerberos 4 tickets, then the Kerberos protocol libraries contact a machine
that is running the krb524 daemon in order to such credentials to the present service
compatible with Kerberos 4. When the krb524 daemon receives a request from a client, it
performs following functions
1. Decryption of the service ticket with the service’s key
2. Extraction of the session key contained inside
3. Creation of a new Kerberos 4 ticket for the same service and client
4. Pasting in the session key from the original Kerberos 5 ticket.
It is important to note that during this process, the session key present inside the original
ticket of Kerberos 5 should be a single DES key. The krb524 daemon will not produce a new
session key but instead it only copies the session key from the present ticket to a new ticket of
Kerberos 4. Given that the Kerberos 4 can only manage the single types of DES key, this
session key should be a single DES key.
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4. TROUBLESHOOTING
4.1 Errors and Solutions:
Here, we’ll run through a few problem cases, starting from the initial indications of a
problem to its solution.
Errors Obtaining an Initial Ticket:
Different errors can take place while trying to achieve an initial “Ticket Granting
Ticket” (TGT) from a KDC of Kerberos. But still there are a lot of ways to obtain a TGT, for
example through integrated login with a “PAM Kerberos” module, the most best and easy
way to solve these problems is by manually implementing the UNIX knit program.
Unsynchronized Clocks:
Commonly, the error message generated when there is a mismatch in the clock which
is self-explanatory. The Network Time Protocol (NTP) fits this un-synchronization properly.
Suppose you are facing a trouble with your Kerberos installation. The very first step to solve
this issue, like solving any other problem, is to finish the main cause that is creating the
trouble. Here, we will determine as if our issue belongs to one of the three different sections
or areas, and will continue our troubleshooting from that point.
A convenient way to categorize an issue including Kerberos authentication is via what
tickets the client can achieve for a better service. It could be one of the three major categories
given below:
Client is unable to get an initial “Ticket Granting Ticket”.
Client possesses a valid TGT but faces some error prior to the achievement of a
service ticket.
Client possesses a valid TGT and has acquired service ticket, but faces error upon
connection to the Kerberized service.
All of an often, especially with some of the more obscure errors that Kerberos can
generate, administrators experience an error per day, solve the problem, then face the same
error after one week, and have to find out the root cause again, only to search out that the
solution is slightly known.
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5. SECURITY
Kerberos is the most popular cross-platform, network-wide authentication system
available, it by no means has a perfect security record. It is true that a lot of thought was put
into making Kerberos as secure as possible; however, there are still security issues that
require much more attention.
It is important that implementing Kerberos on your network does not guarantee
perfect security. While Kerberos is extremely secure in a theoretical sense, there are many
practical security issues to be considered. In addition, it is important to that Kerberos
provides only authentication service; it does not prevent compromises caused by buggy
server software, administrators granting permissions to unauthorized users, or poorly chosen
passwords.
5.1 Kerberos Attacks:
There are some electronic attacks that can compromise the security of your Kerberos system.
1. Root compromise of a Kerberos KDC machine. A root-level compromise of a KDC
machine gives the attacker full control over the entire Kerberos authentication system.
Anyhow the Kerberos database is encrypted on disk with the Kerberos master key, the
master key is also kept on the KDC’s disk so no manual intervention is required (to
enter in the master password) when the KDC service is started.
2. Compromise of a Kerberos administrator’s credentials. If an attacker obtains the
password of a Kerberos administrative principal, then the attacker can get complete
access to the entire Kerberos database. Mostly the KDC implementations allow
administrators to remotely dump the contents of the database for backup purposes,
and an attacker can use this to make a complete copy of your authentication database.
The attacker can also create and modify any Kerberos principal with full access to the
database.
3. Root compromise of a server machine. Some services, such as the AFS distributed file
system, share a single service principal across all servers. In this case, root access to
an AFS file server machine could compromise all file and database servers in the AFS
cell. Once an attacker has access to a service principal’s credentials, the attacker can
impersonate this service and also decrypt the encrypted traffic sent between clients
20. 20
and the compromised service. The security of Kerberized services running on a server
depends on the security of this individual server; for this all servers should be secured
in proportion to the value of the resources stored on that server.
4. Compromise of user credentials. There are two possible scenario: either the user’s
credential (ticket) cache is exposed, or a user’s password is compromised. If an
attacker get the user’s unencrypted credential cache, the tickets contained in that
cache are only valid for the time period specified in the tickets. Also if an attacker
acquires the user’s password, the attacker can impersonate that user until the user
changes his password.
5.2 Other Attacks:
1. Denial of service:
A denial of service attack can be against your organization’s KDCs by flooding them
with authentication requests. The large numbers of requests arriving can slow down response
times to legitimate requests, most of time in extreme cases, crashes the machines in which
KDCs reside. Kerberos cannot protect against denial of service attacks and it is recommended
that your network, including your Kerberos KDCs, be firewalled from the Internet to prevent
this type of attack. Adding additional KDCs to your network for redundancy can overcome
the effects of a DoS attack.
2. The “insider”:
Kerberos does not protect against an internal authorized user who decides to misuse
their privileges. For example, a rogue Kerberos administrator can modify or remove
information from the Kerberos database.
3. Social engineering and password exposure:
Similarly, Kerberos does not protect against individual users who divulge their
passwords to attackers, either inadvertently or as a result of a social engineering attack.
Similarly, Kerberos does not prevent users from reusing their passwords at less secure sites
that may handle passwords in the clear. Hackers who successfully attack a less secure site
where a user has recycled their Kerberos password will obtain a valid username and password
for your Kerberos realm.
21. 21
4. Security holes in the Kerberos software itself:
Unfortunately, with the current state of the art in software engineering, it is very
difficult to write secure code. Just like all other software packages available, every Kerberos
implementation has security issues at some point or another, and these issues can sometimes
lead to a compromise of your KDCs. Therefore, it is important to keep informed of your
Kerberos vendor’s patches, and apply them as soon as they become available.
5.3 Protocol Security Issues:
Kerberos was designed to protect authentication data from passing over a network in
the clear. Kerberos encrypts all authentication exchanges that occur over the network.
Encryption is the only part of the solution, however the designers of Kerberos has put much
thought into ensuring as secure a system as possible.
5.3.1 Dictionary and Brute-Force Attacks:
TGT is encrypted with the user’s secret key (derived from her password). The security
of the whole system is dependent on not being able to decrypt this message, since if an
attacker is able to retrieve the key used to encrypt the message, he can have the user’s
password and can impersonate that user at will. Therefore, if an attacker wishes to obtain a
user’s password, he will ask the KDC for a valid TGT for the victim’s username. While there
are no ways to break the encryption methods used in Kerberos tickets directly, the attacker
can continue to brute-force the decryption of the TGT by launching an offline dictionary
attack.
During a dictionary attack, an attacker use a list of commonly used passwords, or a
dictionary, to a cracking program. For each entry in the dictionary, a program attempts to
decrypt the message using the password. If a hit is made, the program reports back to the
attacker, the user’s password.
5.3.2 Replay Attacks:
All protocol exchanges are simply electronic messages that are sent over a computer
network, an attacker can listen to the network messages involved in a successful
authentication exchange, make a copy of the messages, and replay them at a later time. The
attacker no need to guess the users password or decrypt any messages in this scenario. Since
22. 22
the replay attack requires access to listen to all network messages as well as the ability to
send fake messages, a replay attack is an active attack. A theoretical replay attack is pictured
in figure.
Figure 3: Kerberos replay attack
In this figure, we see that Alice successfully obtains tickets to authenticate to her mail
server. Bob is surreptitiously listening to all network traffic between Alice, the mail server,
and the Kerberos KDC. Bob will not directly use the TGT that Alice requests in the first step,
since the TGT must be decrypted with Alice’s password, which Bob does not know (although
he can try to brute-force the password). However, when Alice sends her encrypted ticket and
authenticator, Bob can intercept that message and replay it to impersonate Alice to the mail
server.
5.3.3 Man-in-the-Middle Attacks:
A man-in-the-middle attack affects most any protocol that attempts to verify the
identity of connection endpoints. A man-in-the-middle attack is an active attack, meaning that
the attacker must be able to read all messages on the network as well as send out arbitrary
messages of his own desire .The goal of in this is to impersonate the server, resulting in the
user thinking that he connected to the desired server, which in fact he is talking to the
attacker. Once the attacker has control of the session, it can act as a simple pass-through
(passing messages between the user and the server, without modification), or can actively
inject, modify, or delete messages between the user and the server. The attacker now is part
of the conversation between the user and the server, and can modify any messages that pass
through him.
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Kerberos protocol has built-in protection against man-in-the-middle attacks. Since Kerberos
performs mutual authentication, by confirming not only the end user’s identity but also the
server’s identity, man-in-the-middle attacks are thwarted.
5.4 Security Solutions:
5.4.1 Requiring Pre-Authentication:
The Microsoft Windows KDC is the only implementation that requires clients to pre-
authenticate by default. In some implementations, a command-line option or flag can be used
to require all clients to use pre authentication. Other implementations require the
administrator to explicitly specify which principals need to pre-authenticate before granting
TGT.
5.4.2 Enforcing Secure Passwords:
The security of your entire network depends on your users choosing passwords.
However, experience shows that most users choose poor passwords. In one realm that already
has password strength-checking in place, over 2,000 passwords in a Kerberos realm
consisting of 25,000 principals were successfully brute force during a 2-week period. This
experiment was performed with a spare CPU cycles available on systems readily available in
1998
5.4.3 Enforcing Password Lifetimes and History:
Policies on password strength, many organizations also specify a maximum lifetime
for user passwords after which the user must change to a new password. Most Kerberos KDC
implementations has enforce a maximum and minimum lifetime for user passwords, as well
as a password history which ensure that users do not simply reuse previous passwords to
evade the mandatory password change.
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6. APPLICATION
Establishing a Kerberos and creating KDCs is only the beginning of creating a
Kerberos-based authentication infrastructure. To get the benefits of Kerberos, we have to
install Kerberos-enabled services and client software. Following are the some applications of
Kerberos:
6.1 Services and Keytabs:
Kerberos provides a service that verifies the identity of two connection endpoints,
which have been identified by unique names, or principals. It is obvious that each user is
associated with a principal name that is stored in the Kerberos database, so all authentication
schemes by their very nature require that all users be uniquely identified with an associated
secret. However, the concept that all services that user contact through Kerberos require a
principal and secret key.
In Windows hosts, service keys are automatically created as needed when Kerberized
services are installed. Unix-based Kerberos systems require a bit more manual configuration.
A service principal has three major components: the service name, the hostname of the
machine that provides the service, and the Kerberos to which the machine belongs A Keytab
files contain highly sensitive information, encryption keys, so it is imperative to ensure
proper access controls to these files. Each Kerberized service should run as a different,
unique username, and the keytab file for that service it should be readable only by that
username. The compromise of a service’s key allows an attacker to masquerade any
authorized principal when communicating to that service, and also allows an attacker to read
any conversation between clients and compromised service.
6.2 Transparent Kerberos Login with PAM:
When a user logs into his workstation, then the user to acquire a Kerberos Ticket
Granting Ticket when he enters his credentials. It is called as transparent Kerberos login. In
Windows 2000, XP, and 2003 automatically acquire tickets for login when the user is part of
a Windows domain. For other systems, we have to configure this step manually. In UNIX,
the simplest and most portable way to get initial credentials for a user upon login is that
through the Pluggable Authentication Modules (PAM), which is available on most operating
systems. Using PAM, you can acquire Kerberos tickets upon logins that occur on the
25. 25
system’s console (and any other network based protocol, but we want to avoid sending
passwords over the network).
If the operating system comes without source, we will not be able to replace the
program with one that performs the necessary authentication method. PAM solves this
problem by providing a standard plug-in interface that both application developers and
authentication method developers can used this to.
6.3 Mac OS X and the Login Window:
The initial console login window presented to Mac OS X users is appropriately
enough, the login window. Unfortunately, login window’s PAM support is incomplete. Apple
has provided special support in the login window for Kerberos 5 users, contained in Mac OS
X 10.2 and above to provide users with Kerberos tickets when logging into their OS X
system.
The Mac OS X Security and Authorization Services use the /etc/ authorization file,
and this is the file which we will use to enable Kerberos authentication in login window.
26. 26
7. ADVANCE TOPIC
7.1 Using Kerberos 4 Services with Kerberos 5:
Those who have Kerberos 4 services that need to be integrated into a Kerberos 5
realm need to implement the Kerberos 5-to-4 ticket translator daemon. Both MIT and
Heimdal include support for this protocol, the krb524 protocol, the only limit on where the
krb524 daemon can run is that the daemon must have access to the service keys for the
Kerberos 4-based services for which it translates tickets.The MIT Kerberos 5 distribution
includes a separate krb524 daemon, krb524d. There are two different modes of operation that
krb524d supports master and keytab. The master mode is meant to be run on a KDC in the
Kerberos realm, and reads the necessary service keys directly from the Kerberos database.
If it is not possible to run the krb524d directly on the KDC, then the second mode of
operation can be used keytab.Keytab mode requires that a Kerberos keytab be installed on the
machine running krb524d that includes the service keys for all of the Kerberos 4 services in
the realm.
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8. KERBEROS FUTURE
8.1 Smart Card:
A smart card is a small, tamperproof computer. The smart card itself contains a CPU
and some non-volatile storage. This capability makes it possible for the card to keep some
secrets, such as the private keys associated with any certificates it holds.
Contact cards require a reader to facilitate the bidirectional connection. The card must
be inserted into a device that touches the contact points on the card, which facilitate
communication with the card’s chip. Contact card readers are commonly built into
company or vendor-owned buildings and assets, cellular phones, handheld devices,
stand-alone devices that connect to a computer desktop’s serial or Universal Serial
Bus (USB) port, laptop card slots, and keyboards.
Contactless cards use proximity couplers to get information to and from the card’s
chip. An antenna is wound around the circumference of the card and activated when
the card is radiated in a specific distance from the coupler.
8.1.1 Why Smart Cards:
Smart cards are a key component of the public key infrastructure (PKI) that Microsoft
is integrating into the Windows platform because smart cards enhance software-only
solutions, such as client authentication, logon, and secure email. Smart cards are a point of
convergence for public key certificates and associated keys because they:
Provide storage for protecting private keys and other forms of personal information
Isolate security-critical computations, involving authentication, digital signatures, and
key exchange from other parts of the system that don’t have a need to know.
8.2 Better Encryption:
The art and algorithms of cryptography are always driven by the growth in computer
power and cryptographic theory. Increasing computer power provides a dual driving force for
emerging cryptographic algorithms: first, it solved older algorithms and short key lengths as
they fall to practical brute-force attacks.
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A 56-bit single DES key can be brute forced by a network of commodity computers in
less than a week, and that time is decreasing rapidly. Conversely, the increase in computing
power makes possible the complex calculations of even more sophisticated algorithms and
longer key lengths necessary to secure information.
Because Kerberos is a system that depends heavily on cryptography, it is crucial that
these new encryption methods are implemented in the Kerberos protocol. The
Kerberos 5 protocol was designed to be extendable and support multiple encryption
type’s implementations is single DES. Thankfully, the upcoming release of MIT
Kerberos 1.3 will provide wider support for the RC4-HMAC encryption type first
introduced by Microsoft for use in Windows 2000’s Kerberos service.
For further growth, there are proposed Internet Drafts that specify more, stronger
encryption options for future implementations.
8.3 Referrals:
Current implementations of the Kerberos Authentication Service (AS) and ticket-
Granting Service (TGS) protocols use names constructed from a known user or service name.
A service name is typically constructed from a name of the service and the DNS host name of
the computer that is providing the service. Many existing employments of Kerberos use a
single Kerberos realm where all users and services would be using the same realm. However,
in an environment where here are multiple Kerberos realms, the client needs to be able to
determine what realm a particular user or service is in before making an AS or TGS request.
Traditionally, this requires client configuration to make this possible. However, in many
cases, the user would like to use a more familiar name that is not directly related to the realm
of their Kerberos principal name. In practice, this would be the name that the user specifies
to obtain a TGT from a Kerberos KDC.
Once a TGT has been obtained, the user would like to be able to access services in
any Kerberos realm for which there is an authentication path from the realm of their
principal. To do this requires that the client be able to determine what realm the target
service principal is in before making the TGS request. Current implementations of Kerberos
typically have a table that maps DNS host names to corresponding Kerberos realms. This
mechanism requires that each client have very detailed configuration information about the
hosts that are providing services and their corresponding realms.
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A solution for these problems and simplifies administration by minimizing the
configuration information needed on each computer using Kerberos.
Two kinds of KDC referrals are introduced:
1. Client referrals, in which the client doesn't know which realm contains a user account.
2. Server referrals, in which the client doesn't know which realm contains a server
account.
8.4 Web Services:
Web services security encompasses a number of requirements, such as authentication,
authorization, and message protection.
Because of its nature and its use of open access SOA implemented by Web services
adds a new set of requirements to the security landscape:
Authentication— verifying that the user is who she claims to be. A user's identity is verified
based on the credentials presented by that user, such as:
Authorization (or Access Control) — Granting access to specific resources based on an
authenticated user's entitlements.
Confidentiality, privacy— keeping information secret. Accesses a message, for example a
Web service request or an email, as well as the identity of the sending and receiving parties in
a confidential manner. Confidentiality and privacy can be achieved by encrypting the content
of a message.
Integrity, non-repudiation— making sure that a message remains unaltered during transit by
having the sender digitally sign the message.
8.4.1 Web Service Security Requirements:
Use transport security to protect the communication channel between the web service
consumer and web service provider.
Use message-level security to ensure confidentiality by digitally encrypting message
parts; integrity using digital signatures; and authentication by requiring username,
X.509, or SAML tokens.
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8.4.2 Web Service Security Using Kerberos:
Standards for Web services security are required to ensure interoperability in
heterogeneous environments. The WS Security Standard and its dependents such as a WS-
Trust and WS-Security Policy are important standards in this area. WS-Security is security
token agnostic, allowing the use of a variety of security token types. One security token type
that is popular in Intranet scenarios is the Kerberos token. This is largely because Kerberos is
an integral part of the security system in Microsoft Active Directory server.
It is reasonable to expect that Web services' security interoperability should be
achievable using these standards.
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9. REFERENCES
1. http://web.mit.edu/rhel-doc/5/RHEL-5-manual/Deployment_Guide-en-US/ch-
kerberos.html
2. https://en.wikipedia.org/wiki/Kerberos_%28protocol%29
3. Research report on “The Evolution of the Kerberos Authentication Service” by John.T
and B.Clifford
4. Research report on “Verifying Confidentiality and Authentication in Kerberos 5” by
Fredrick Butler,IlianoCorvesato and Andre Scedrov.
5. https://www.drupal.org/project/kerberos_authentication
6. http://www.kerberos.org/software/tutorial.html
7. https://www.safaribooksonline.com/library/view/kerberos-the-
definitive/0596004036/ch06s06.html
8. https://tools.ietf.org/html/rfc1510