Computer Security science and enggineering
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Computer Security science and enggineering

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This talk is intended for Graduate or Under graduate students as an attempt to motivate them into this exciting field of computer security ...

This talk is intended for Graduate or Under graduate students as an attempt to motivate them into this exciting field of computer security

This talk is by no means complete although constantly evolves to be comprehensive

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Computer Security science and enggineering Computer Security science and enggineering Presentation Transcript

  • Security  Science   And   Engineering Sashank DaraThis work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 1
  • This talk is intended for Graduate or Under graduatestudents as an attempt to motivate them into thisexciting field of computer securityThis talk is by no means complete although constantlyevolves to be comprehensive This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 2
  • Science This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 3
  • Engineering This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 4
  • Flaws  can  be  Disastrous This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 5
  • Boundaries  to  breach Bumble  bee  aerodynamically  cannot  fly,  what  does  this  mean  ? This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 6
  • Symbols  and  Interpretation Engineering  application, Scientific  Theory,   Product Framework, Mathematical  Model Scope  for   A  Flaw  either  in  theory  or breaching   in  application  that  resulted theoretical  or   In  disaster practical       boundaries   This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 7
  • Foundations •  Authentication•  Authorization•  Confidentiality•  Integrity•  Non Repudiation•  Availability ( Non Denial of service)Note : Any a security application, appliance orresearch would be about achieving combination ofabove properties or their variants This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 8
  • Authentication Less  formally  ,  this  involves  confirming  the  identity  of  a  person   or  software  program.  “you  are  who  you  say  you  are” This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 9
  •  Factors  and  Identity •  Ownership Factors, something the user has, say ID Card, Security token, Phone etc.•  Knowledge Factors, something the user knows, say password, passphrase, PIN, challenge response•  Inherence Factors, something the user is or does, say finger print, DNA sequence, retinal scan, voice, facial recognition•  Two factor authentication is an approach to authentication which requires the presentation of "two or more" of the three authentication "factors" This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 10
  • Applications •  Single sign-on, a user logs in once and gains access to all systems without being prompted to log in again at each of them•  Open-Id, Users may create accounts with their preferred OpenID identity providers, and then use those accounts as the basis for signing on to any website which accepts OpenID authentication.•  Kerberos, is a computer network authentication protocol which works on the basis of "tickets" to allow nodes prove their identity to one another in a secure manner.•  BrowserID is a decentralized identity system that makes it possible for users to prove ownership of email addresses in a secure manner, without requiring per-site passwords•  Two-Factor authentication This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 11
  • Caveats •  Security experts argue that it is impossible to prove the identity of a computer user with absolute certainty. Any given test can be spoofed one way or another, with varying degrees of difficulty. – Wikipedia•  Strong Passwords are difficult to remember•  Finger printing has been successfully spoofed using glue and thumb impressions•  Facial recognition can be beaten using photographs !•  Voice can be easily mimicked !•  ID Cards, Phones, Security Tokens can be subjected to theft !•  U S Government defines strong authentication as layered authentication approach relying on two or more authenticators to establish the identity of an originator or receiver of information. This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 12
  • Authorization Function  of  specifying  access  rights  to  resources, More  formally,  "ʺto  authorize"ʺ  is  to  define  access  policy.   This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 13
  • Authorization •  For example, human resources staff are normally authorized to access employee records, and this policy is usually formalized as access control rules in a computer system.•  During operation, the system uses the access control rules to decide whether access requests from (authenticated) consumers shall be approved (granted) or disapproved (rejected) This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 14
  • Access  Control Access  Control  includes  Authentication,  Authorization,  Audit This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 15
  • Two  Steps •  Policy definition phase where access is authorized o  This step is more of Authorization phase•  Policy enforcement phase where access requests are approved or disapprovedThis work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 16
  • Access  Control  Lists •  In short a list of permissions attached to an object or a collection of objects•  File system ACLs, is a data structure (usually a table) containing entries that specify individual user or group rights to specific system objects such as programs, processes, or files.•  Network ACLs, is a list of rules specifying the services that can be accessed by inbound and outbound traffic. o  Firewalls predominantly are based on ACL’s o  Famous five tuple ( Source IP , Destination IP, Source port , Dest Port , action) This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 17
  • Security  Models •  Discretionary based access control o  Users (owners) have the ability to make policy decisions and/or assign security attributes. o  Example is Unix file mode info represented by rwx bits•  Mandatory based access control o  Decision making authorities have the ability to make policy decisions and/ or assign security attributes o  Users do not have ability to make policy decisions o  Example is SELinux framework•  Role based access control o  Combination of DAC and MAC, typically used in enterprisesThis work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 18
  • Security  Models •  Context based access control o  Deep packet and stateful inspection of firewalls•  Capability based Security o  a capability is a token, ticket, or key that gives the possessor permission to access an entity or object in a computer system o  In contrast there are no ACLs !•  There are many other modelsThis work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 19
  • Mathematical  models •  Conflicts in access control list can open up security holes ! o  Often misconfiguration of firewalls resulted in disasters !•  Can we mathematically model access control list ? o  Boolean logic o  Lattice based access control models•  Can we prove they are formally correct and complete ?This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 20
  • User  level  Access  Control •  Identity management, describes the management of individual identities, their authentication, authorization, roles , and privileges o  Password managers, LDAP, Etc.•  OAuth allows users to share their private resources (e.g. photos, videos, contact lists) stored on one site with another site without having to hand out their credentials, typically supplying username and password tokens instead o  Complimentary to OpenID•  SAML, Secure Assertion Markup Language is an XML-based open standard for exchanging authentication and authorization data between security domains. o  Primarily to solve and standardize single sign on o  Quite popular among identity based solutions This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 21
  • Network  Access  Control •  Firewalls, often touted as first layer of defense in any organization’s security design•  First generation firewalls were mere packet filters based on five tuple•  Second generation firewalls are stateful and do deep packet inspection•  Third generation firewalls are more “context-aware” This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 22
  • Confidentiality Confidentiality  is  the  concept  of  ensuring  that  data   is  not  made  available  or  disclosed  to  unauthorized   people. This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 23
  • Integrity Data  Integrity  in  broadest  meaning  refers  to  the  trustworthiness   of  information  over  its  entire  life  cycle This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 24
  • Cryptography •  Cryptography simple stated is the art of “Secret writing”•  Traditional Cryptography has been used successfully for authentication, confidentiality, integrity•  Confidentiality cannot be achieved without cryptography o  Exception a technique called chaffing and winnowing was proposed but that is not practically strong enoughThis work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 25
  • Cryptography •  Art of secret writing dates back to thousands of years•  cryptography was chiefly concerned with linguistic and lexicographic patterns until twentieth century•  Now extensive use of of mathematics, including aspects of information theory, computational complexity, statistics, combinatorics, abstract algebra, number theory, and finite mathematics generally•  And lately even quantum theory and chaos theory too ! This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 26
  • Cryptanalysis Myth:  The  Enigma  was  too  complex  to  be   broken -­‐‑  ...  as  believed  by  the  German  Military •  Fact:  The  Enigma  was  broken  almost  daily  for  years  during  WWII This particular work by Landon Curt Noll is Licensed under CC Attribution-Share Alike 3.0 Unported License 27
  • Cryptographic  Engg •  Many implementation challenges o  Key management o  Pseudo Random Number Generators o  Side channel attacks o  Tamper proof hardware o  Verification techniques o  Protocol Analysis This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 28
  • Protocols •  Secure Sockets Layer (SSL/TLS)•  IP Sec•  VPN’s•  PGP•  Many many to name a few This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 29
  • Caveats •  Myth: The larger the key, the stronger the key•  Fact: Key size is no guarantee of key strength•  An early web browser with 128-bit SSL keys o  Key was generated by the random() pseudo-random number generator o  With only 4 billion different srandom() seeds, only 4 billion different SSL keys could ever be generated o  Only 32 bits of real protection•  There are more important issues than size: o  - Generating keys that cannot be guessed o  - Securely storing keys o  - How humans use a key o  - How unattended machines use a key o  - Lost key recovery o  - Key life-cycle management This particular work by Landon Curt Noll is Licensed under CC Attribution-Share Alike 3.0 Unported License 30
  • Caveats •  Large Key but Weak Key Example, The US “nuclear football” o  Nuclear launch authorization code was long but until 1976, the code was all 0’s!!! Really !!!•  Larger keys do not necessarily mean better o  Key size cannot overcome a predictable method of generating it o  A huge compromised key is much worse than a smaller well-managed key o  The cost of discovering the key must be higher than the value of the data being protected This particular work by Landon Curt Noll is Licensed under CC Attribution-Share Alike 3.0 Unported License 31
  • Applications •  Entire Web Commerce infrastructure SETS,HTTPS•  Virtual Private Networking•  IPSEC•  Cryptography in wireless applications (mobile phone, WLANs, analysis of standards, etc.)•  Cryptography for pervasive computing (RFID, sensor networks, smart devices, etc.)•  FPGA design security•  Hardware IP protection and anti-counterfeiting•  Reconfigurable hardware for cryptography This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 32
  • Applications •  Smart card processors, systems and applications•  Security in commercial consumer applications (pay- TV, automotive, domotics, etc.)•  Secure storage devices (memories, disks, etc.•  Technologies and hardware for content protection•  Trusted computing platforms This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 33
  • Non  Repudiation This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 34
  • Non  Repudiation •  A service that provides proof of the integrity and origin of data.•  An authentication that with high assurance can be asserted to be genuine.•  Entire Public Key Infrastructure is built for this This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 35
  • Availability                                   (  Non  Denial  of  Service) This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 36
  • Denial  of  Service •  A DoS attack can be perpetrated in a number of ways. The five basic types of attack are: o  Consumption of computational resources, such as bandwidth, disk space, or processor time. o  Disruption of configuration information, such as routing information. o  Disruption of state information, such as unsolicited resetting of TCP sessions. o  Disruption of physical network components. This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 37
  • Denial  of  Service •  A DoS attack may include execution of malware intended to: o  Max out the processors usage, preventing any work from occurring. o  Trigger errors in the microcode of the machine. o  Trigger errors in the sequencing of instructions, so as to force the computer into an unstable state or lock-up. o  Exploit errors in the operating system, causing resource starvation and/or thrashing, i.e. to use up all available facilities so no real work can be accomplished. o  Crash the operating system itself.•  Few DOS Attacks o  Smurf attack , Ping flood , Ping of death, SYN FloodThis work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 38
  • Intrusion  Prevention   systems •  Are network security appliances that monitor network and/or system activities for malicious activity•  First generation were Intrusion Detection Systems•  Classification o  Network based o  Host based o  Wireless IPS o  Network Behavior Analysis•  IPS checks for malware, worm outbreaks, DDOS attacks•  An IPS can also correct Cyclic Redundancy Check (CRC) errors, un fragment packet streams, prevent TCP sequencing issues, and clean up unwanted transport and network layer options. This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 39
  • Intrusion  Prevention   systems •  Detection Methods o Signature Methods o Statistical anomaly detection o Stateful protocol Analysis Detection•  Other Recent Trends o  IP Reputation o  Global Correlation•  Popular IPS (Open Source) o SnortThis work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 40
  • Security  Principles •  Security is an afterthought , internet was built to share physics documents among researchers but not social networking, commerce and everything•  Security by obscurity is disastrous, o   Kerckhoff’s principle A cryptosystem should be secure even if everything about the system, except the key, is public knowledge.•  Security is as strong as its weakest link and often its the people.•  There is no silver bullet•  Security is a process rather than a product.•  Defense in depth•  Risk Assessment , Threat modeling , compliance can mitigate This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 41
  • Conclusions •  Few things not yet covered o  Cloud security o  Threat modeling o  Popular Attacks o  Secure Development Life cycle o  Social Engineering o  Security Management o  Many Others ..•  This talk is a work in progress, so it would be continually evolving do come back to check for latest revisions of the file This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 42
  • Contact •  I can be reached at o  Krishna.sashank@iiitb.org o  http://www.linkedin.com/in/sashankdara•  Note : Parts of the work is taken from Landon Curt Noll as mentioned in the foot notes where ever relevant. o  He can be reached at http://isthe.com/chongo/ This work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 43
  • This work is made available under CreativeCommons Attribution-Share Alike 3.0Images courtesy : Google ImagesThis work by Sashank Dara is licensed under CC Attribution-ShareAlike 3.0 Unported 44