The document provides a history of cryptography from ancient times to modern day. It describes early manual encryption techniques used by ancient Greeks and Romans. In the Middle Ages, Arabic scholar Al-Kindi developed frequency analysis to break ciphers. During the Renaissance period, the polyalphabetic cipher was introduced. In World War 1 and 2, mechanical encryption machines like the Enigma and SIGABA were widely used. Modern cryptography began with Claude Shannon's mathematical foundations and the introduction of the Data Encryption Standard (DES) in the 1970s. Public key cryptography was then introduced in the 1970s through Diffie-Hellman key exchange.
The document discusses data encryption using the Data Encryption Standard (DES) and Triple DES (TDES) functionality in Spartan-II FPGAs. It describes how DES and TDES are commonly used encryption algorithms and how a FPGA-based solution from Xilinx and Xentec provides scalability, flexibility and performance for applications requiring data encryption. It also provides technical details on how the DES algorithm works using permutations, substitutions and XOR operations over multiple rounds to encrypt data blocks.
The document summarizes the Data Encryption Standard (DES) cryptographic algorithm. It was issued in 1977 by the National Bureau of Standards as the Federal Information Processing Standard for data encryption. DES uses a 56-bit key to encrypt 64-bit blocks of plaintext into ciphertext using 16 rounds of permutations and substitutions. While the algorithm and its use of 56-bit keys were once considered secure, concerns were later raised about weaknesses in the algorithm's substitution tables and the possibility of timing attacks on implementations.
DES is a widely-used method of data encryption that uses a private key chosen from 72 quadrillion possible keys to encrypt 64-bit blocks of data using 16 rounds of operations. While DES is considered strong encryption, some use triple DES for additional security. In 1997, a cooperative effort of 14,000 computers broke a DES encrypted message by trying 18 quadrillion keys out of the 72 quadrillion possibilities. DES originated at IBM in 1977 and was adopted by the U.S. government but export was restricted due to security concerns, though free software is now widely available. NIST will not recertify DES and is accepting submissions for its AES replacement standard.
The document provides a history of cryptography from ancient times to modern day. It describes early manual encryption techniques used by ancient Greeks and Romans. In the Middle Ages, Arabic scholar Al-Kindi developed frequency analysis to break ciphers. During the Renaissance period, the polyalphabetic cipher was introduced. In World War 1 and 2, mechanical encryption machines like the Enigma and SIGABA were widely used. Modern cryptography began with Claude Shannon's mathematical foundations and the introduction of the Data Encryption Standard (DES) in the 1970s. Public key cryptography was then introduced in the 1970s through Diffie-Hellman key exchange.
The document discusses data encryption using the Data Encryption Standard (DES) and Triple DES (TDES) functionality in Spartan-II FPGAs. It describes how DES and TDES are commonly used encryption algorithms and how a FPGA-based solution from Xilinx and Xentec provides scalability, flexibility and performance for applications requiring data encryption. It also provides technical details on how the DES algorithm works using permutations, substitutions and XOR operations over multiple rounds to encrypt data blocks.
The document summarizes the Data Encryption Standard (DES) cryptographic algorithm. It was issued in 1977 by the National Bureau of Standards as the Federal Information Processing Standard for data encryption. DES uses a 56-bit key to encrypt 64-bit blocks of plaintext into ciphertext using 16 rounds of permutations and substitutions. While the algorithm and its use of 56-bit keys were once considered secure, concerns were later raised about weaknesses in the algorithm's substitution tables and the possibility of timing attacks on implementations.
DES is a widely-used method of data encryption that uses a private key chosen from 72 quadrillion possible keys to encrypt 64-bit blocks of data using 16 rounds of operations. While DES is considered strong encryption, some use triple DES for additional security. In 1997, a cooperative effort of 14,000 computers broke a DES encrypted message by trying 18 quadrillion keys out of the 72 quadrillion possibilities. DES originated at IBM in 1977 and was adopted by the U.S. government but export was restricted due to security concerns, though free software is now widely available. NIST will not recertify DES and is accepting submissions for its AES replacement standard.
The document summarizes the Data Encryption Standard (DES) algorithm in three main steps:
1. It provides background on how DES was developed by the National Bureau of Standards in response to growing needs for data encryption. DES was adopted as a standard in 1977.
2. It explains the basic mechanics of how DES works, including that it operates on 64-bit blocks of plaintext using 56-bit keys, and generates subkeys through permutations and shifts of the main key.
3. It gives an example of encrypting a sample plaintext message in hexadecimal using DES, showing how the message is padded and divided into blocks for encryption.
Cryptography is the practice of securing communications and data through encryption techniques. It aims to achieve authentication, privacy, integrity, and non-repudiation. The development of computers allowed for more complex encryption of digital data. There are different types of cryptography including secret key cryptography which uses a single key, and public key cryptography which uses different keys for encryption and decryption. Cryptography provides a secure way to transmit data and is necessary for communications over untrusted networks like the Internet.
Cryptography is the science of keeping information secret. It allows for confidentiality, authentication, integrity, and nonrepudiation. There are two main types of encryption algorithms: symmetric which uses a single shared key, and asymmetric which uses a public/private key pair. Hashing algorithms are used to verify integrity rather than keep information secret. Common symmetric algorithms include AES and DES, while RSA and DSA are examples of asymmetric algorithms. Cryptanalysis involves attempting to break or bypass cryptography. Cryptography should be used anywhere secret communication or stored data is needed such as in SSL, VPNs, and encrypted file systems.
DES was developed as a standard for communications and data protection by an IBM research team in response to a request from the National Bureau of Standards (now called NIST). DES uses the techniques of confusion and diffusion achieved through numerous permutations and the XOR operation. The basic DES process encrypts a 64-bit block using a 56-bit key over 16 complex rounds consisting of permutations and key-dependent calculations. Triple DES was developed as a more secure version of DES.
Cryptography is a method of securing communication and information by encoding messages in such a way that only authorized parties can access it. It involves encrypting plaintext using an algorithm and key to create ciphertext, which can then be decrypted using the same key. Common uses of cryptography include ensuring data privacy, authenticity, integrity, and non-repudiation. Symmetric key encryption uses the same key for encryption and decryption while asymmetric key encryption uses different public and private keys.
Encryption is used to hide information from unauthorized parties by translating plaintext files into ciphertext using secret codes. Cryptography involves mathematically scrambling data using keys so that only those with the necessary key can access the information. Technological advances both increased risks by making data more accessible but also reduced risks through strong encryption techniques.
Cryptography is the practice of hiding information by converting plain text into unreadable cipher text using encryption keys. There are two main types of encryption: symmetric encryption which uses the same key for encryption and decryption, and asymmetric encryption which uses a public key known to everyone and a private key kept secret. The document discusses the basic concepts and terminology in cryptography such as encryption, decryption, plain text, cipher text, and symmetric and asymmetric encryption key types.
Cryptography involves encrypting plaintext data into ciphertext using encryption algorithms and keys. Conventional cryptography uses a single secret key for both encryption and decryption, while public key cryptography uses separate public and private keys. The combination of these methods in hybrid cryptosystems like PGP provides both the speed of conventional encryption and the key distribution benefits of public key cryptography.
This document provides an overview of cryptography basics including its history, key terminologies, symmetric and asymmetric encryption methods, public key infrastructure (PKI), and digital certificates. It discusses how cryptography has evolved over centuries with advances made during world wars and by notable cryptographers. Symmetric and asymmetric encryption methods are defined along with associated terminologies like plaintext, ciphertext, hashes, and block ciphers. The roles of digital certificates and public key infrastructure in authentication are also summarized.
Encryption works by using algorithms and keys to secure digital information during transmission. Symmetric-key encryption uses the same secret key between two computers, while public-key encryption uses separate public and private keys. A popular implementation of public-key encryption is Secure Sockets Layer (SSL) and its successor Transport Layer Security (TLS), which allow for secure transmission of sensitive information on the internet through the use of encryption during online transactions.
Asymmetric key cryptography uses two keys: a public key and a private key. The public key can encrypt messages but only the private key can decrypt them. This allows for convenience, message authentication, detection of tampering, and non-repudiation. However, public keys need authentication, it is slower than symmetric key cryptography, uses more computer resources, a security compromise could affect many users, and loss of the private key would be irreparable.
This document provides an overview of encryption, including its history, types, methods, and uses. Encryption is the process of converting plain text into ciphertext using an algorithm and key. Historically, ancient Babylonian merchants used carved stones for encryption. There are several types of encryption, including manual, transparent, symmetric, and asymmetric encryption. Encryption methods are categorized as stream or block cipher encryption. Encryption is used to protect information on computers, in transit such as for wireless phones, and to facilitate confidential transactions and digital signatures.
Cryptography is a method of protecting information and communications through the use of codes. It involves techniques such as encrypting plaintext into ciphertext using a key, and back again through decryption. Modern cryptography aims for confidentiality, integrity, non-repudiation and authentication of digital information. It uses cryptosystems, keys and algorithms to encrypt and decrypt data between senders and receivers over secure channels.
This document provides an overview of cryptography concepts including symmetric and asymmetric key algorithms, cryptographic hashes, and tools for cryptanalysis. It defines common terminology like plaintext, ciphertext, encryption, and decryption. Symmetric algorithms discussed include the Vernam cipher, A5/1, DES, AES, and RC4. Asymmetric algorithms covered are RSA and Diffie-Hellman key exchange. Cryptographic hashes like MD5 and SHA-1 are also summarized along with resources for cryptanalysis.
WHAT IS CRYPTOGRAPHY - A COMPREHENSIVE GUIDESprintzeal
Get COUPON CODES LINKEDIN10 visit https://www.sprintzeal.com/blog/what-is-cryptography
Introduction to Cryptography
Cryptography is a technique of secure communications that allows a particular sender and intended recipient of a message to view its contents. The term is obtained from the Greek word “Kryptos”, which means “hidden, secret”. More generally, cryptography is about establishing and analyzing protocols that avert third parties or the public from reading personal messages. Moreover, it works on the various aspects of information security such as data confidentiality, data integrity, authentication, and non-repudiation.
This document discusses the design and implementation of the Blowfish encryption algorithm using Verilog HDL. Blowfish is a symmetric block cipher that uses a variable-length key from 32 to 448 bits, making it suitable for securing data. The algorithm consists of two parts - key expansion and a round structure involving 16 rounds of operations. The authors implemented Blowfish using Verilog HDL on a Xilinx FPGA for applications requiring encryption like IoT devices. Their design achieved high-speed encryption of up to 4 bits per clock cycle and operated at a maximum frequency of 50MHz.
Cryptography is a method of protecting information through codes and involves encryption and decryption processes. Encryption encodes messages into cipher text using a key, while decryption decodes cipher text back into the original plain text. There are two main types of encryption - symmetric which uses the same key for encryption and decryption, and asymmetric which uses different public and private keys. Common encryption algorithms include the Advanced Encryption Standard (AES).
The document provides an introduction to cryptography including definitions of terms and topics covered. It discusses symmetric-key cryptography and algorithms like substitution ciphers, transposition ciphers, DES, AES and their modes of operation. It also covers asymmetric-key cryptography including RSA and Diffie-Hellman key exchange with examples of encrypting and decrypting messages.
This document summarizes cryptography and cryptanalysis. It discusses:
1) Cryptography concepts like encryption, decryption, symmetric and asymmetric encryption algorithms. Symmetric algorithms include block and stream ciphers while asymmetric includes RSA.
2) Applications of cryptography in areas like the military, banking, and internet.
3) Cryptanalysis techniques like brute force attacks and chosen plaintext attacks used to break encryption. It provides an example of how the Enigma machine was broken during WWII.
The document summarizes the Data Encryption Standard (DES) algorithm in three main steps:
1. It provides background on how DES was developed by the National Bureau of Standards in response to growing needs for data encryption. DES was adopted as a standard in 1977.
2. It explains the basic mechanics of how DES works, including that it operates on 64-bit blocks of plaintext using 56-bit keys, and generates subkeys through permutations and shifts of the main key.
3. It gives an example of encrypting a sample plaintext message in hexadecimal using DES, showing how the message is padded and divided into blocks for encryption.
Cryptography is the practice of securing communications and data through encryption techniques. It aims to achieve authentication, privacy, integrity, and non-repudiation. The development of computers allowed for more complex encryption of digital data. There are different types of cryptography including secret key cryptography which uses a single key, and public key cryptography which uses different keys for encryption and decryption. Cryptography provides a secure way to transmit data and is necessary for communications over untrusted networks like the Internet.
Cryptography is the science of keeping information secret. It allows for confidentiality, authentication, integrity, and nonrepudiation. There are two main types of encryption algorithms: symmetric which uses a single shared key, and asymmetric which uses a public/private key pair. Hashing algorithms are used to verify integrity rather than keep information secret. Common symmetric algorithms include AES and DES, while RSA and DSA are examples of asymmetric algorithms. Cryptanalysis involves attempting to break or bypass cryptography. Cryptography should be used anywhere secret communication or stored data is needed such as in SSL, VPNs, and encrypted file systems.
DES was developed as a standard for communications and data protection by an IBM research team in response to a request from the National Bureau of Standards (now called NIST). DES uses the techniques of confusion and diffusion achieved through numerous permutations and the XOR operation. The basic DES process encrypts a 64-bit block using a 56-bit key over 16 complex rounds consisting of permutations and key-dependent calculations. Triple DES was developed as a more secure version of DES.
Cryptography is a method of securing communication and information by encoding messages in such a way that only authorized parties can access it. It involves encrypting plaintext using an algorithm and key to create ciphertext, which can then be decrypted using the same key. Common uses of cryptography include ensuring data privacy, authenticity, integrity, and non-repudiation. Symmetric key encryption uses the same key for encryption and decryption while asymmetric key encryption uses different public and private keys.
Encryption is used to hide information from unauthorized parties by translating plaintext files into ciphertext using secret codes. Cryptography involves mathematically scrambling data using keys so that only those with the necessary key can access the information. Technological advances both increased risks by making data more accessible but also reduced risks through strong encryption techniques.
Cryptography is the practice of hiding information by converting plain text into unreadable cipher text using encryption keys. There are two main types of encryption: symmetric encryption which uses the same key for encryption and decryption, and asymmetric encryption which uses a public key known to everyone and a private key kept secret. The document discusses the basic concepts and terminology in cryptography such as encryption, decryption, plain text, cipher text, and symmetric and asymmetric encryption key types.
Cryptography involves encrypting plaintext data into ciphertext using encryption algorithms and keys. Conventional cryptography uses a single secret key for both encryption and decryption, while public key cryptography uses separate public and private keys. The combination of these methods in hybrid cryptosystems like PGP provides both the speed of conventional encryption and the key distribution benefits of public key cryptography.
This document provides an overview of cryptography basics including its history, key terminologies, symmetric and asymmetric encryption methods, public key infrastructure (PKI), and digital certificates. It discusses how cryptography has evolved over centuries with advances made during world wars and by notable cryptographers. Symmetric and asymmetric encryption methods are defined along with associated terminologies like plaintext, ciphertext, hashes, and block ciphers. The roles of digital certificates and public key infrastructure in authentication are also summarized.
Encryption works by using algorithms and keys to secure digital information during transmission. Symmetric-key encryption uses the same secret key between two computers, while public-key encryption uses separate public and private keys. A popular implementation of public-key encryption is Secure Sockets Layer (SSL) and its successor Transport Layer Security (TLS), which allow for secure transmission of sensitive information on the internet through the use of encryption during online transactions.
Asymmetric key cryptography uses two keys: a public key and a private key. The public key can encrypt messages but only the private key can decrypt them. This allows for convenience, message authentication, detection of tampering, and non-repudiation. However, public keys need authentication, it is slower than symmetric key cryptography, uses more computer resources, a security compromise could affect many users, and loss of the private key would be irreparable.
This document provides an overview of encryption, including its history, types, methods, and uses. Encryption is the process of converting plain text into ciphertext using an algorithm and key. Historically, ancient Babylonian merchants used carved stones for encryption. There are several types of encryption, including manual, transparent, symmetric, and asymmetric encryption. Encryption methods are categorized as stream or block cipher encryption. Encryption is used to protect information on computers, in transit such as for wireless phones, and to facilitate confidential transactions and digital signatures.
Cryptography is a method of protecting information and communications through the use of codes. It involves techniques such as encrypting plaintext into ciphertext using a key, and back again through decryption. Modern cryptography aims for confidentiality, integrity, non-repudiation and authentication of digital information. It uses cryptosystems, keys and algorithms to encrypt and decrypt data between senders and receivers over secure channels.
This document provides an overview of cryptography concepts including symmetric and asymmetric key algorithms, cryptographic hashes, and tools for cryptanalysis. It defines common terminology like plaintext, ciphertext, encryption, and decryption. Symmetric algorithms discussed include the Vernam cipher, A5/1, DES, AES, and RC4. Asymmetric algorithms covered are RSA and Diffie-Hellman key exchange. Cryptographic hashes like MD5 and SHA-1 are also summarized along with resources for cryptanalysis.
WHAT IS CRYPTOGRAPHY - A COMPREHENSIVE GUIDESprintzeal
Get COUPON CODES LINKEDIN10 visit https://www.sprintzeal.com/blog/what-is-cryptography
Introduction to Cryptography
Cryptography is a technique of secure communications that allows a particular sender and intended recipient of a message to view its contents. The term is obtained from the Greek word “Kryptos”, which means “hidden, secret”. More generally, cryptography is about establishing and analyzing protocols that avert third parties or the public from reading personal messages. Moreover, it works on the various aspects of information security such as data confidentiality, data integrity, authentication, and non-repudiation.
This document discusses the design and implementation of the Blowfish encryption algorithm using Verilog HDL. Blowfish is a symmetric block cipher that uses a variable-length key from 32 to 448 bits, making it suitable for securing data. The algorithm consists of two parts - key expansion and a round structure involving 16 rounds of operations. The authors implemented Blowfish using Verilog HDL on a Xilinx FPGA for applications requiring encryption like IoT devices. Their design achieved high-speed encryption of up to 4 bits per clock cycle and operated at a maximum frequency of 50MHz.
Cryptography is a method of protecting information through codes and involves encryption and decryption processes. Encryption encodes messages into cipher text using a key, while decryption decodes cipher text back into the original plain text. There are two main types of encryption - symmetric which uses the same key for encryption and decryption, and asymmetric which uses different public and private keys. Common encryption algorithms include the Advanced Encryption Standard (AES).
The document provides an introduction to cryptography including definitions of terms and topics covered. It discusses symmetric-key cryptography and algorithms like substitution ciphers, transposition ciphers, DES, AES and their modes of operation. It also covers asymmetric-key cryptography including RSA and Diffie-Hellman key exchange with examples of encrypting and decrypting messages.
This document summarizes cryptography and cryptanalysis. It discusses:
1) Cryptography concepts like encryption, decryption, symmetric and asymmetric encryption algorithms. Symmetric algorithms include block and stream ciphers while asymmetric includes RSA.
2) Applications of cryptography in areas like the military, banking, and internet.
3) Cryptanalysis techniques like brute force attacks and chosen plaintext attacks used to break encryption. It provides an example of how the Enigma machine was broken during WWII.
A digital signature is an electronic signature that can authenticate the identity of the sender of a message and ensure that the message has not been altered. Digital signatures are easily transportable, cannot be imitated, and are automatically time-stamped. A digital signature can be used with any message, whether encrypted or not, to verify the sender's identity and that the message was not changed. Digital certificates contain the digital signature of the certificate authority to verify that the certificate is authentic.
Secret writing refers to cryptography and steganography. Cryptography involves encrypting messages so only authorized users can read them, while steganography hides information within other files or mediums. Common cryptographic techniques include symmetric and asymmetric encryption methods. Symmetric encryption uses a shared key between sender and receiver, while asymmetric encryption uses public and private key pairs. Steganography hides information by embedding it within images or other files.
1. The document discusses the science of cryptology, which includes cryptography and cryptanalysis. Cryptography is the science of secure communications through encryption and decryption techniques.
2. Cryptography includes symmetric and asymmetric encryption methods. Symmetric methods like block and stream ciphers encrypt fixed blocks or individual bits using a shared key. Asymmetric methods like RSA use public/private key pairs to encrypt and decrypt messages.
3. Cryptanalysis involves techniques to decrypt encrypted messages without access to the key, such as brute force attacks. The document discusses how the Allies were able to break Germany's Enigma cipher during World War II through cryptanalysis.
The document provides an introduction to cryptography including definitions of terms and topics covered. It discusses symmetric-key cryptography and algorithms like substitution ciphers, transposition ciphers, DES, AES and their modes of operation. It also covers asymmetric-key cryptography including RSA and Diffie-Hellman key exchange with examples of encrypting and decrypting messages.
Cryptography involves secret writing and encrypting messages so that only authorized parties can read them. It uses algorithms and keys to encrypt plaintext into ciphertext. Cryptanalysis involves breaking ciphers, while cryptography is designing ciphers. Cryptology encompasses both cryptography and cryptanalysis. Common encryption models involve plaintext being encrypted into ciphertext using a key, which is then transmitted and decrypted by the intended receiver using the same key.
The document discusses the history and concepts of cryptography. It covers:
1) Cryptography is the science of secret codes and involves both encrypting messages and trying to break codes.
2) Modern cryptography uses both symmetric encryption, which uses the same key to encrypt and decrypt, and asymmetric encryption, which uses different public and private keys.
3) Key challenges include securely distributing keys and making encryption algorithms that are easy to use but difficult to break without the key.
CRYPTOLOGY AND INFORMATION SECURITY - PAST, PRESENT, AND FUTURE ROLE IN SOCIETYijcisjournal
This article provides a general introduction to the subject of Cryptology, Crytography and Crytoanalysis and explains the terminology and the practical application of security techniques… In recorded History , technological innovations have revolutionized societies. The printing press is an often-cited example of the great impact one humble person’s invention can have on ruling dynasties, world religions, and personal life.. Quantum encryption could rival Guttenberg’s printing press in its impact. Cryptology has a fascinating History., In Warfare Cryptography is a broad, sticky, and mathematically complex, but interesting subject and an integral part of the evolution of warfare. So let’s get some definitions out of the way first. Cryptology is the study of codes, both creating and solving them. Cryptography is the art of creating codes. Cryptanalysis is the art of surreptitiously revealing the contents of coded messages, breaking codes, that were not intended for you as a recipient.. Secondly, there are nomenclators and enciphers. Nomenclators are letters or numbers that represent words or phrases, like 103A means “meet me at 4PM”. Ciphers are alphabetical letters or numbers that are encrypted using some sequential coding process and a key. For this essay, we will refer to both as codes. Also, enciphered, encrypted and encoded mean the same thing….Additionally, there is plain text. This is the original message that is readable and understandable, uncoded or unencrypted. Once it goes through the coding process and is encrypted, the output is readable but not understandable. There are a bunch of other terms like steganography, homophones, polyphones, digraphs, bigrams, and polygrams, but they are just variations of coding and decoding techniques.
The document discusses the history and evolution of cryptography. It describes early cryptography techniques like the Caesar cipher and transposition ciphers. The development of frequency analysis allowed cryptanalysis of these classical ciphers. The polyalphabetic cipher was developed in the 15th century in response and provided more security until modern times. The document outlines the progression of cryptography from ancient times to its importance today in ensuring privacy, security and integrity.
BEGINS FROM SCRATCH TO FUTURE METHODS OF CRYPTOGRAPHY. PROVIDES A DEEP INSIGHT INTO HISTORY,USES,APPLICATION,DIFFERENT TYPES AND METHODS OF CRYPTOGRAPHY. THANK YOU
Encryption has a long history dating back to ancient times. Various methods were used throughout history including cipher wheels, the Enigma machine, and public/private key cryptography. Modern encryption uses algorithms to scramble data into an unreadable format called ciphertext that can only be decrypted by someone with the proper decryption key. Encryption provides critical security benefits like protecting data privacy and integrity and ensuring compliance with regulations. As technology advances, new encryption methods like elliptic curve cryptography and homomorphic encryption aim to make encryption even stronger and more versatile.
Cryptography is the practice of securing communication and information by converting plaintext into ciphertext. The document provides an introduction to cryptography including its history from ancient times to the present. It discusses terminology like plaintext, encryption, ciphertext, decryption, and keys. Symmetric key cryptography uses a single key for encryption and decryption while asymmetric key cryptography uses two different keys. Examples of symmetric methods are DES, 3DES, AES, and RC4, while RSA is a common asymmetric method. Applications of cryptography include ATMs, email passwords, e-payments, e-commerce, electronic voting, defense services, securing data, and access control.
This document provides an overview of cryptography and encryption techniques. It discusses the basic cryptographic terms and historical background of cryptography. It then describes different cipher techniques including transposition cipher and substitution cipher. It also discusses conventional encryption algorithms such as DES, AES, and RSA. Symmetric key cryptography and public key cryptography are explained. The document also covers digital signatures, cryptanalysis, and cryptographic systems in general.
Encryption is a process of encoding information in a way that only authorized parties can read it. It was first used over 2000 years ago by Julius Caesar and ancient Greeks to hide military communications. There are two main types of encryption - symmetric encryption which uses the same key to encrypt and decrypt, and public-key encryption which uses a public key to encrypt and a private key to decrypt. Encryption is now widely used to protect data on computers and transmitted over networks by individuals, companies and governments.
Cryptography is the practice of protecting information by converting it into an unreadable format. Only using a secret key can the information be converted back to a readable format. Throughout history, different encryption techniques have been developed including the Caesar cipher, the Vigenere cipher, and public key cryptography developed by Diffie and Hellman. Modern cryptography is used for purposes such as authentication, electronic money, secure network communication, anonymous remailers, and disk encryption. However, widespread use of unbreakable encryption could enable criminal activity and threaten national security and business interests.
Cryptography is the science of using mathematics to encrypt and decrypt data. This presentation explains about the cryptography, its history, types i.e. symmetric and asymmetric cryptography.
Sri Hari Uppalapati gave a presentation on the One Time Pad (OTP) encryption method. OTP uses a randomly generated key that is as long as the plaintext message. The key is used to encrypt the message one time and then discarded, making it impossible to decrypt the ciphertext without the key. OTP is information theoretically secure if implemented correctly, but it is not practical for most uses due to the key management issues. The presentation received average to good peer reviews, with comments noting the clear explanations but room for improvement. Reviewers suggested providing more examples or comparisons to other methods.
Symmetric key encryption uses a secret key that is shared between two computers to encrypt and decrypt messages sent between them. Public key encryption addresses the weakness of needing to securely share a key beforehand by using a hashing algorithm to generate keys from input values, making it nearly impossible to derive the original input without knowing the data used to create the hash. A popular implementation of public key encryption is Secure Sockets Layer (SSL) and its successor Transport Layer Security (TLS), which are Internet security protocols used by browsers and servers to transmit sensitive information securely.
Advanced cryptography and implementationAkash Jadhav
The document discusses a technical presentation on advanced cryptography and its implementation. It provides an overview of cryptography, including its history and basic concepts such as encryption, decryption, and cryptanalysis. Examples of cryptography applications discussed include ATM cards, credit cards, e-mail, and lottery tickets.
This document contains a summary of an introductory chapter from the Handbook of Applied Cryptography. It provides an overview of cryptography and discusses its purpose in ensuring information security. The key goals of cryptography are described as confidentiality, data integrity, authentication, and non-repudiation. Various cryptographic primitives and techniques are introduced that can provide these security properties, such as encryption schemes, hash functions, and digital signatures. The chapter also discusses criteria for evaluating cryptographic primitives like security level, functionality, performance, and ease of implementation.
This document contains a summary of cryptography and cryptographic techniques. It discusses how cryptography can be used to provide information security by ensuring confidentiality, integrity, authentication, and non-repudiation. It defines cryptography and outlines some of its main goals. It also introduces common cryptographic primitives like encryption schemes, hash functions, and digital signatures, and how they relate to each other and can be combined to meet security objectives.
This document provides a literature review of cryptography and its role in network security. It begins with an abstract and then discusses early versus modern cryptography. It identifies overall trends in the research, including that cryptography serves as the foundation for most IT security solutions. It reviews both scholarly and non-scholarly literature on the topic. The scholarly literature section discusses research studies on topics like identity management, group key establishment protocols, wireless security, software vulnerability analysis, and chosen ciphertext attacks. The review concludes that continuing research into cryptography is important for preserving electronic data security and privacy.
This document provides an introduction and table of contents to cryptography. It discusses the main goals of cryptography which are confidentiality, data integrity, authentication, and non-repudiation. It then defines key vocabulary terms used in cryptography such as plaintext, ciphertext, encryption, decryption, stream ciphers, block ciphers, and cryptosystems. Finally, it provides a brief high-level history of cryptography mentioning examples from 400 BC Spartan sky tale cipher to Julius Caesar's substitution cipher.
This document provides an overview of RSA encryption. It discusses the history of cryptography from early ciphers like the Caesar cipher to the development of public-key cryptography. Researchers Ron Rivest, Adi Shamir, and Leonard Adleman developed the RSA algorithm in 1977, which introduced the first practical public-key encryption. The document then explains how the RSA algorithm works by generating a public and private key pair based on large prime numbers, and how encryption and decryption utilize these keys along with exponentiation and modulo arithmetic. Number theory concepts like Fermat's Little Theorem and Euler's Theorem are also discussed to explain why RSA provides a one-way function and ensures only the private key holder can decrypt messages.
This document is a project report submitted by Gaurav Shukla for his internship at IIT Kanpur under the guidance of Mr. B.M. Shukla. The report compares secured message delivery using SSL and GPG. It provides background on cryptography, describes how SSL and GPG work to securely transmit messages, and analyzes parts of the GPG source code to observe cryptographic flaws. The document contains sections on certificate, acknowledgements, introduction to cryptography concepts, descriptions of SSL and GPG, results and analysis of comparing the two methods, conclusions, and bibliography.
Similar to Security Systems for Digital Data - Paper (20)
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
A Mix Chart displays historical data of numbers in a graphical or tabular form. The Kalyan Rajdhani Mix Chart specifically shows the results of a sequence of numbers over different periods.
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
Project Management Semester Long Project - Acuityjpupo2018
Acuity is an innovative learning app designed to transform the way you engage with knowledge. Powered by AI technology, Acuity takes complex topics and distills them into concise, interactive summaries that are easy to read & understand. Whether you're exploring the depths of quantum mechanics or seeking insight into historical events, Acuity provides the key information you need without the burden of lengthy texts.
Your One-Stop Shop for Python Success: Top 10 US Python Development Providersakankshawande
Simplify your search for a reliable Python development partner! This list presents the top 10 trusted US providers offering comprehensive Python development services, ensuring your project's success from conception to completion.
Webinar: Designing a schema for a Data WarehouseFederico Razzoli
Are you new to data warehouses (DWH)? Do you need to check whether your data warehouse follows the best practices for a good design? In both cases, this webinar is for you.
A data warehouse is a central relational database that contains all measurements about a business or an organisation. This data comes from a variety of heterogeneous data sources, which includes databases of any type that back the applications used by the company, data files exported by some applications, or APIs provided by internal or external services.
But designing a data warehouse correctly is a hard task, which requires gathering information about the business processes that need to be analysed in the first place. These processes must be translated into so-called star schemas, which means, denormalised databases where each table represents a dimension or facts.
We will discuss these topics:
- How to gather information about a business;
- Understanding dictionaries and how to identify business entities;
- Dimensions and facts;
- Setting a table granularity;
- Types of facts;
- Types of dimensions;
- Snowflakes and how to avoid them;
- Expanding existing dimensions and facts.
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
Discover how MongoDB Atlas and vector search technology can revolutionize your application's search capabilities. This comprehensive presentation covers:
* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
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
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!
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
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
Skybuffer SAM4U tool for SAP license adoptionTatiana Kojar
Manage and optimize your license adoption and consumption with SAM4U, an SAP free customer software asset management tool.
SAM4U, an SAP complimentary software asset management tool for customers, delivers a detailed and well-structured overview of license inventory and usage with a user-friendly interface. We offer a hosted, cost-effective, and performance-optimized SAM4U setup in the Skybuffer Cloud environment. You retain ownership of the system and data, while we manage the ABAP 7.58 infrastructure, ensuring fixed Total Cost of Ownership (TCO) and exceptional services through the SAP Fiori interface.
Salesforce Integration for Bonterra Impact Management (fka Social Solutions A...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on integration of Salesforce with Bonterra Impact Management.
Interested in deploying an integration with Salesforce for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Digital Marketing Trends in 2024 | Guide for Staying AheadWask
https://www.wask.co/ebooks/digital-marketing-trends-in-2024
Feeling lost in the digital marketing whirlwind of 2024? Technology is changing, consumer habits are evolving, and staying ahead of the curve feels like a never-ending pursuit. This e-book is your compass. Dive into actionable insights to handle the complexities of modern marketing. From hyper-personalization to the power of user-generated content, learn how to build long-term relationships with your audience and unlock the secrets to success in the ever-shifting digital landscape.
Digital Marketing Trends in 2024 | Guide for Staying Ahead
Security Systems for Digital Data - Paper
1. Bernhard Hofer CIST 3100 03/10/08
University of Nebraska at Omaha
Management Information Systems
Spring 2008
Bernhard Hofer
Individual Presentation – Security Systems for Digital Data
CIST 3100 – Organizations, Applications & Technology
Instructor: Victoria Badura
Date: 03/10/08
Presentation Assignment Page 1 of 17
2. Bernhard Hofer CIST 3100 03/10/08
Table of Contents
Introduction .................................................................................................................... 3
A Brief history about cryptography ................................................................................. 4
Terminology of cryptography.......................................................................................... 6
Encrypting Digital Data................................................................................................... 7
General Information .................................................................................................... 7
Symmetric key system (private key)............................................................................ 8
Block ciphers........................................................................................................... 8
Stream cipher .......................................................................................................... 9
Asymmetric key system (public key)......................................................................... 10
Problems with one way asymmetric encryption ..................................................... 11
The solution .......................................................................................................... 11
The Internet – Big Brother is watching YOU................................................................. 13
Requirements for secure interaction........................................................................... 14
Useful applications.................................................................................................... 15
Protect Your Password .............................................................................................. 16
The Future: Quantum Cryptography.............................................................................. 16
Presentation Assignment Page 2 of 17
3. Bernhard Hofer CIST 3100 03/10/08
Introduction
Nowadays, nobody would send important information over the Internet without securing
them properly. Nobody? That is the big question of this paper. The Internet is grown to
the largest information network in the world and that nearly over night, in the last
century. A lot of people use it and don’t think about the consequences it has to send
important and/or confidential information over the public network Internet. This paper
and the corresponding slides should give an insight into how data could be secured, in
particular, how data could be encrypted to use the Internet as an information channel for
important data.
This document is a combination of the slides and a description of the mentioned topics in
more detail. Every information provided in this document is related to a slide of the
presentation to show the connection. Furthermore, this presentation is not held for IT
specialists and contains no detailed information about the algorithms and background
knowledge about ciphering systems. Again, the main purpose of this document is to give
an overview of the bandwidth of the field cryptography and how everybody, even for
private purposes, could use technology to secure data. To take a single example, the goal
is to tell people how to send an encrypted email to other people. By this way, I hope I
could galvanize the audience and give some basic information about the most common
cipher methods used in the modern information world, the Internet.
Presentation Assignment Page 3 of 17
4. Bernhard Hofer CIST 3100 03/10/08
A Brief history about cryptography
From the beginning people always want to share information private. Ronald Rivest, the
founder of RSA, describes it that way “Encryption is the standard means of rendering a
communication private” (R. Rivest, A. Shamir, L. Adleman. A Method for Obtaining
Digital Signatures and Public-Key Cryptosystems. Communications of the ACM, Vol. 21
(2), pp.120–126. 1978). This matter of fact has not changed over the times. One of the
first documented use of a form of cryptography was in Egypt’s Old Kingdom over 4.500
years ago. It was a very easy system, but definitely efficient. They used non-standard
hieroglyphs to communicate in privacy with each other. As nearly every technological
development was made by the military, also this method was used for military purposes.
The Greeks of Classical times enhanced cryptography and were the first people, who
used a key to encrypt and decrypt messages also known as transcription cipher
(Wikipedia, http://en.wikipedia.org/wiki/Transposition_cipher, 03/10/08 9:45am). They
Presentation Assignment Page 4 of 17
5. Bernhard Hofer CIST 3100 03/10/08
had a wood stock and wrapped a piece of paper around it. Then a message was written on
this piece of paper and after unwrapping it, the message was delivered to the receiver.
The receiver had the same wood stick and by wrapping the piece of paper on his stick, the
receiver could decrypt the message.
The important thing is the usage of a key, which produces a message, which is not
readable for anybody without the key. The key in this case is the diameter of the wood
stick.
Another common technique was to replace a text letter by letter with some fixed number
of positions further down the alphabet. This method was called Caesar cipher, because
the emperor used it so sent encrypted messages to his generals on the battlefield. For
instance, if there is the world “hello”, Caesar replaced each letter with three further down
the alphabet. “hello” becomes “khoor” (regarding David Kahn, The Codebreakers — The
Story of Secret Writing, 1967).
After this early development the next big steps were done during World War I and World
War II. Cryptography became a hard science and a lot of new technologies got
developed. For example the Enigma machine of the Germans, which was an elaborate
system to encrypt and decrypt messages. But the big problem with all these developments
was that if the adversary gets the wood stick, knows the number of shifts in the alphabet
or has an Enigma machine every message could be decrypted and, of course, wrong
messages can be encrypted to confuse the other party.
It was not until 1976, however, that in a groundbreaking paper, Whitfield Diffie and
Martin Hellman proposed the notion of public-key (also, more generally, called
asymmetric key) cryptography in which two different but mathematically related keys are
used — a public key and a private key. From this time on, the world of cryptography
changed a lot from it’s beginnings and opened the door for a whole bunch of new
technologies (Whitfield Diffie and Martin Hellman, “Multi-user cryptographic
techniques", AFIPS Proceedings 45, pp109–112, 1976).
Presentation Assignment Page 5 of 17
6. Bernhard Hofer CIST 3100 03/10/08
Terminology of cryptography
The word cryptography or cryptology derived from Greek κρύπτω kryptó "hidden" and
the verb γράφω gráfo "to write" or λέγειν legein "to speak". Which has a combined
meaning of “secret writing” (Liddell and Scott's Greek-English Lexicon, Oxford
University Press, 1984).
There are some other important terms provided on this slide above. “Until modern times,
cryptography referred almost exclusively to encryption, the process of converting
ordinary information (plaintext) into unintelligible gibberish (ciphertext)” (David Kahn,
The Codebreakers — The Story of Secret Writing, 1967). Decryption is the reverse,
moving from unintelligible ciphertext to plaintext. A cipher is a pair of algorithms, which
creates the encryption and the reversing decryption. The detailed operation of a cipher is
controlled both by the algorithm and, in each instance, by a key. This is a secret
parameter (ideally, known only to the communicants) for a specific message exchange
Presentation Assignment Page 6 of 17
7. Bernhard Hofer CIST 3100 03/10/08
context. Keys are important, as ciphers without variable keys are trivially breakable and
therefore less than useful for most purposes. Historically, ciphers were often used directly
for encryption or decryption, without additional procedures such as authentication or
integrity checks (regarding Wikipedia, http://en.wikipedia.org/wiki/Cryptography,
03/10/08 10:23am).
Encrypting Digital Data
General Information
Again I would like to cite Ronald Rivest, who said that “Cryptography is about
communication in the presence of adversaries” (Ronald Rivest, "Cryptography" From the
Handbook of Theoretical Computer Science, edited by J. van Leeuwen, Elsevier Science
Publishers B.V., 1990).
Modern cryptography is spliced into two big parts of how to encrypt data. At the one
hand there are symmetric methods. By this method both, the sender and the receiver,
share the same key to encrypt and decrypt a message. “This was the only kind of
encryption publicly known until June 1976” (Whitfield Diffie and Martin Hellman, "New
Directions in Cryptography", IEEE Transactions on Information Theory, vol. IT-22, Nov.
1976, pp: 644–654). On the other hand there are the asymmetric methods, which consists
of two different keys. These two different keys are mathematically related to each other,
but you can’t encrypt and decrypt a message with only one of them. On the following
pages, these two methods are described in more detail.
Presentation Assignment Page 7 of 17
8. Bernhard Hofer CIST 3100 03/10/08
Symmetric key system (private key)
As mentioned before, the sender and the receiver share the same key. The big advantage
of this method is that it is very fast and don’t need a lot of hardware resources. On the
other side the really big disadvantage is that if the key get lost or fall into the wrong
hands, this method is not secure any more.
There are two methods how to encrypt/decrypt a message with symmetric key systems, in
particular block and stream ciphers.
Block ciphers
A block cipher is a symmetric key cipher, which operates on fixed-length groups of bits,
with an unvarying transformation. When encrypting, a block cipher might take a (for
instance) 128-bit block of plaintext as input, and output a corresponding 128-bit block of
Presentation Assignment Page 8 of 17
9. Bernhard Hofer CIST 3100 03/10/08
cipher text. The exact transformation is controlled using a second input — the secret key.
The decryption process is similar, the decryption algorithm takes, in this example, a 128-
bit block of cipher text together with the secret key, and yields the original 128-bit block
of plaintext. To encrypt messages longer than the block size (128 bits in the above
example), a mode of operation is used (regarding Wikipedia,
http://en.wikipedia.org/wiki/Block_ciphers, 03/10/08 11:43am).
The most common block cipher systems are DES, AES, IDEA, Camellia and Twofish.
Stream cipher
A stream cipher is a symmetric cipher where plaintext bits are combined with a
pseudorandom cipher bit stream (keystream), typically by an exclusive-or (xor)
operation. In a stream cipher the plaintext digits are encrypted one at a time, and the
transformation of successive digits varies during the encryption. An alternative name is a
state cipher, as the encryption of each digit is dependent on the current state. In practice,
the digits are typically single bits or bytes (regarding Wikipedia,
http://en.wikipedia.org/wiki/Stream_cipher, 03/10/08 11:43am).
An example is the following:
Plaintext: Hello
Cipher: cist
Cipher text: Kne fr
The really big problem with stream cipher is that if you have the plaintext and the cipher
text it is very easy to find out the cipher algorithm and/or the key, which is used. This
problem is very relevant on WEP encryption standard for Wireless LAN.
The most common stream cipher systems are RC4, SEAL, A5 and Bluetooth-Standard
E0.
Presentation Assignment Page 9 of 17
10. Bernhard Hofer CIST 3100 03/10/08
Asymmetric key system (public key)
As mentioned before, the Asymmetric key system was founded by Diffie and Hellman in
1976 an opened a completely knew understanding how to encrypt data. This system uses
two different keys, which are mathematically related to each other. There is the so-called
public key and the private key. This method is deeply based on mathematic and needs a
lot of more hardware resources than the symmetric key system. By this matter of fact,
asymmetric key systems are very slow in comparison to symmetric key systems.
There are two ways how a message could be encrypted. On the one hand the sender could
encrypt the message with his private key and the receiver decrypt the message with the
public key of the sender. Or on the other hand, the sender encrypt the message with the
public key of the receiver and the receiver decrypt the message with his private key.
Presentation Assignment Page 10 of 17
11. Bernhard Hofer CIST 3100 03/10/08
Problems with one way asymmetric encryption
There is one big problem for each of the mentioned methods how to encrypt data with an
asymmetric system above. Firstly there is a confidentiality problem, because everybody
with the public key of the sender could encrypt the message. The receiver knows who
sent the message, because just the sender could have the private key. But for the sender it
is not really secure. Secondly there is an authentication problem, because the sender
encrypts the message with the public key of the receiver and so the receiver doesn’t
exactly know, from whom the message is. It is guaranteed that the message could just
read by the receiver, but the problem here lies in the hands of the receiver, because there
is no authentication of the sender possible.
The solution
Presentation Assignment Page 11 of 17
12. Bernhard Hofer CIST 3100 03/10/08
If the process is repeated twice, every disadvantage of each run could be suspended by
the other run. Which means that the sender and the receiver use a double handshake
process to verify their authentications and, of course, the confidentiality of their
messages.
In practical use now message is encrypted by asymmetric systems, because it takes too
long and the process needs too much hardware resources as well. The logical solution is
that the asymmetric system is used to share a symmetric key between the sender and the
receiver. If both know the key, they could communicate secure with a symmetric system.
The big problem of symmetric key methods is to share the key, which is eliminated by
using the asymmetric key system to share just the symmetric key.
A really good example for this combination of the two methods is the Secure Socket
Layer (or SSL) protocol, which is used over the Internet to guarantee secure data
exchange. The browser and the server, for example of a on-line banking system,
exchange a symmetric key by using an asymmetric key system. This happens every day
in hour life in the background and works very well.
Presentation Assignment Page 12 of 17
13. Bernhard Hofer CIST 3100 03/10/08
The Internet – Big Brother is watching YOU
Know the only question is, why are this encryption technologies so important for
everybody? The answer is very easy, because the Internet is a big public and local
structure. With other words, the Internet is a none secure and open information system for
everybody like private people, the public authorities and, of course, economic player.
Cryptography is the only way for privacy and protection of personal data over the World
Wide Web. This matter of fact makes the whole encryption topic so important for
everybody of us.
Presentation Assignment Page 13 of 17
14. Bernhard Hofer CIST 3100 03/10/08
Requirements for secure interaction
This slide shows the five big points of the prerequisites, which must be accomplished for
a secure interaction (Andreas Pfitzmann, “Security in IT Networks: Multilateral Security
in Distributed and by Distributed Systems”, 2001).
Presentation Assignment Page 14 of 17
15. Bernhard Hofer CIST 3100 03/10/08
Useful applications
This is just a short overview of technologies, which enables us to communicate secure
over the Internet. One of the most common applications is PGP, which was founded by
Phil Zimmermann in 1991. PGP stands for Pretty Good Privacy (Zimmerman, Phil,
“Why I Wrote PGP”, 1991). One of the advantages of PGP is that it encrypts emails
automatically and shares a key with the receiver of the message. It uses an asymmetric
key system (RSA and IDEA) and is also very common for the usage of Digital Signature.
Digital Signature is nothing else than a certificate, which guarantees the receiver of a
message that the message was sent from the person he expects. It is also part of an
asymmetric system. The Secure Socket Layer (SSL) protocol mentioned before one of
the big applications, which helps us to communicate in a secure way over unsecured
networks as well.
Presentation Assignment Page 15 of 17
16. Bernhard Hofer CIST 3100 03/10/08
Protect Your Password
The biggest problem is not to hack an encryption method; it is that people use very easy
passwords, which are wide opened for Brute-Force-Attacks. There is a whole bunch of
other methods to steal passwords from people, which would break the mold of this paper.
Just to mention a few of them like Fishing, Sniffing, Cross Side Attacks, etc.
The Future: Quantum Cryptography
I would like to give a short overview about the upcoming technologies in this area. One
of the biggest developments was the use of quantum physics to encrypt data. Basically
Quantum cryptography, or quantum key distribution (QKD), uses quantum mechanics to
guarantee secure communication. It enables two parties to produce a shared random bit
string known only to them, which can be used as a key to encrypt and decrypt messages
(H. Chau, Physical Review A 66, 60302, 2002).
Presentation Assignment Page 16 of 17
17. Bernhard Hofer CIST 3100 03/10/08
The really cool thing is that if somebody interferes or tries to wiretap the encrypted
message, the message itself get destroyed or modified so that the receiver of a message
knows, if somebody tried to read it.
The Austrian researcher Anton Zeilinger first implemented this technology between BA
CA bank and the Vienna City-Hall over a 1,500m FDDA cable in April 2004. This
experiment first showed the versatility of this technology in the daily business life and
was a forecast for future developments (Will Knight, “Entangled photons secure money
transfer”, NewScientist, April 2004).
Presentation Assignment Page 17 of 17