Fundamentals of Computer Security. one-time pad A cipher invented by Vernam in which the key is a random sequence of symbols having the same length as the plaintext. cipher suite In SSL and TLS, the combination of key exchange, hash, and encryption algorithms. MixRows In Whirlpool, an operation similar to MixColumns in AES except that rows, instead of columns, are mixed. Cryptography & Network Security By: Dr. Kapil Gupta 2. security attacks Attacks threatening the security goals of a system. data expansion function In TLS, a function that uses a predeﬁned HMAC to expand a secret into a longer one. irreducible polynomial A polynomial of degree n with no divisor polynomial of degree less than n. An irreducible polynomial cannot be factored into a polynomial with degree of less than n. iterated cryptographic hash function A hashing function in which a function with ﬁxedsize input is created and is used a necessary number of times. message transfer agent (MTA) An e-mail component that transfers messages across the Internet. We have a dedicated category for articles on user demand. --Publisher's website. Digital Signature Algorithm (DSA) The digital signature algorithm used by the Digital Signature Standard (DSS). 702 GLOSSARY Security Policy Database (SPD) A database of security policies (SPs). Cyber Security is the practice of defending the servers, networks, data, and other things related to network and computing from the attackers. Kerckhoff’s principle A principle in cryptography that one should always assume that the adversary knows the encryption/decryption algorithm. Each block is then divided into four 6-bit section. Share this article to make people aware. [Sti06] Stinson, D. Cryptography: Theory and Practice. The position of the single 1 deﬁnes the value of the integer. All the Cyber Security Service providing companies try to provide the best security to their clients. Hypertext Transfer Protocol (HTTP) An application-layer service for retrieving a Web document. congruence If n is a positive integer, two integers a and b are said to be congruent modulo n, a ≡ b (mod n), if a − b = kn, for some integer k. congruence operator The operator (≡) used in a congruence relation. In this new first edition, well-known author Behrouz Forouzan uses his accessible writing style and visual approach to simplify the difficult concepts of cryptography and network security. New York: Chapman & Hall / CRC, 2006. false acceptance rate (FAR) The parameter measuring how often the system recognizes a person who should not be recognized. We do not charge for this service. hashing A cryptographic technique in which a ﬁxed-length message digest is created from a variable-length message. ElGamal cryptosystem An asymmetric-key cryptosystem, devised by ElGamal, which is based on the discrete logarithm problem. She then analyzes the plaintext/ciphertext pairs to ﬁnd the cipher key. claimant In entity authentication, the entity whose identity needs to be proved. Internet Protocol Security (IPSec) A collection of protocols designed by the IETF to provide security for a packet at the network level. distributivity In an algebraic structure with two operations divisibility If a and b are integers and a ≠ 0, we say that a divides b if there is an integer k such that b = k × a. divisibility test The most elementary deterministic method for a primality test in which the number is declared a prime if all numbers less than n cannot divide it. determinant A scalar value deﬁned for a square matrix. info@dokumen.pub square matrix A matrix with the same number of rows and columns. In this article, we will see the role of Cryptography in the field of Cyber Security. modulus The divisor in modular arithmetic. Cryptographic Message Syntax (CMS) The syntax used in S/MIME that deﬁnes the exact encoding scheme for each content type. key-distribution center (KDC) A trusted third party that establishes a shared secret key between two parties. denial of service The only attack on the availability goal that may slow down or interrupt the system. Fermat factorization method A factorization method in which an integer n is divided into two positive integers a and b so that n = a × b. n Fermat number A set of integers in the form Fn = 22 + 1, where n is an integer. It will help you in understanding the role of Cryptography in this field. Without Cryptography, Cyber Security will become weak. R Rabin cryptosystem A variation of the RSA cryptosystem, devised by M. Rabin, in which the value of e and d are ﬁxed to 2. second preimage resistance A desired property in a cryptographic hash function in which given M and h(M) the intruder cannot ﬁnd another message M′ such that h(M′) = h(M). [PHS03] Pieprzyk, J., Hardjono, T., and Seberry, J. Chinese remainder theorem (CRT) A theorem that proves that there exists a unique solution for a set of congruent equations with one variable if the moduli are relatively prime. private key In an asymmetric-key cryptosystem, the key used for decryption. The method is similar to the cipher block chaining (CBC) mode. round Each iterated section in an iterative block cipher. superincreasing tuple A tuple in which each element is greater than or equal to the sum of all previous elements. encoding The term has many deﬁnitions. Secure Hash Algorithm (SHA) A series of hash function standards developed by NIST and published as FIPS 180. web of trust In PGP, the key rings shared by a group of people. public-key infrastructure (PKI) A model for creating and distributing certiﬁcates based on X.509. It deals with developing and analyzing protocols which prevents malicious third parties from retrieving information being shared between two entities thereby following the various aspects of information security. What Can Malicious Code Do – Types and Prevention, What Is Human Firewall – Protect your companies from Data Breaches and Cyber Attacks, What Is Trojan Horse Virus Example, Types, Working, Netflix Phishing Email Attack 2020- Cyber Threat. Natick, MA: A. K. Peters, 1999. This Cyphertext is considered as encrypted and secured text. Upper Saddle River, NJ: Prentice Hall, 2002. public key In an asymmetric-key cryptosystem, the key used for encryption. false rejection rate (FRR) The parameter measuring how often the system fails to recognize a person who should be recognized. It is mostly based on MD5. The ﬁrst and the third stages use K1; the second stage uses K2. word In AES, a group of 32 bits that can be treated as a single entity, a row matrix of four bytes, or a column matrix of four bytes. Norwell, MA: Kluver Academic, 1999. You can check our dedicated article on Cryptography on our site. D data confidentiality A security service designed to protect data from disclosure attacks, snooping, and trafﬁc analysis. 9781259029882, 1259029883 entity authentication A technique designed to let one party prove the identity of another party. An Introduction to Security Information and Event Management (SIEM), Cyber Attack Prevention Plans You Need To Know, What is SQL Injection Attack? Michael Browner output feedback (OFB) mode A mode of operation similar to CFB but the shift register is updated by the previous r-bit key. undeniable signatures A signature scheme invented by Chaum and van Antwerpen with three components: a signing algorithm, a veriﬁcation protocol, and a disavowal protocol. Digital Signature Standard (DSS) The digital signature standard adopted by NIST under FIPS 186. digram A two-letter string. 687 688 GLOSSARY authentication exchange A security mechanism in which two entities exchange a set of messages to prove their identity to each other. Cryptography in Cyber Security increase the confidence of users. differential cryptanalysis A type of chosen-plaintext attack introduced by Biham and Shamir that uses the differential proﬁle of S-boxes to attack a product cipher. elliptic curves digital signature scheme (ECDSA) A digital signature algorithm based on DSA but using elliptic curves. Secure Sockets Layer (SSL) A protocol designed to provide security and compression services to data generated from the application layer. [Bis05] Bishop, M. Computer Security. Now, we will see the role of Cryptography in Cyber Security in detail. Index 2DES See double DES 3DES See triple DES A A5/1 242–244 abelian group 98, 322 access control 7, 8 active attack 5 additive cipher 62–63 Caesar cipher 62–63 cryptanalysis 63 shift cipher 62–63 additive inverse 35 elliptic curve 324 addressing 604–605 Address Resolution Protocol (ARP) 603 AddRoundKey 206, 382 Adobe Post Script 495 Advanced Encryption Standard (AES) 191 AddRoundKey 206 alternative design 214 bits 193 brute-force attack 219 bytes 193 cipher 213 differential and linear attacks 219 implementation 219 InvAddRoundKey 215 inverse cipher 213 InvSubBytes 198 key expansion 207 key-adding 206 MixColumns 204 mixing 203 number of rounds 192 original design 213 permutation 202 round constants 209 security 219 state 193 statistical attacks 219 structure of each round 195 SubBytes 196 substitution 196 words 193 AES See Advanced Encryption Standard afﬁne cipher 66–67 AH See Authentication Header Alert Protocol 526 algebraic structures 19, 97 American National Standards Institute (ANSI) 600 American Standard Code for Information Interchange (ASCII) 593 anonymous DifﬁeHellman 510 AND operation 106 ANSI X9.17 PRNG 636 application layer 602 AS See authentication server ASK Algorithm 261 ASN.1 456 associativity 98 asymmetric-key ciphers 57 asymmetric-key cryptography 293 asymmetric-key encipherment 9 asymptotic complexity 641 asynchronous stream cipher 154 Atbash cipher 96 attack 3 chosen-ciphertext 60 chosen-plaintext 60 ciphertext-only 58 discrete logarithm 449 known-plaintext 59 man-in-the-middle 449 masquerading 4 modiﬁcation 4 on digital signature 395 on implementation 309 on random Oracle Model 347 709 710 INDEX attack—Cont.