UNIT-I Overview of cryptography : Need of security, cryptographic goals, security approaches, basic terminology and concepts, symmetric key encryption - block cipher and stream cipher, substitution cipher and transposition ciphers, key space, public key cryptography, symmetric key v/s public key cryptography. Protocols and mechanisms, key management through symmetric key and public key techniques, attacks on encryption schemes, attacks on protocols, models for evaluating security, perspective for computational security. UNIT-II Pseudorandom bits and sequences : Random bit generation – hardware based generator and software based generator, tests for measuring randomness – frequency, serial, poker, runs and autocorrelation test. Blum-Blum-Shub pseudorandom bit generator. Stream ciphers: Classification, one time pad, properties of synchronous and self-synchronizing stream cipher, linear and nonlinear feedback shift registers, stream ciphers based on LFSRs and its property, SEAL. UNIT-III Block ciphers : Modes of operation – ECB, CBC, CFB and OFB mode, exhaustive key search and multiple encryption, classical ciphers – transposition and substitution based ciphers, Vigenere ciphers, cryptanalysis of classical ciphers, Data Encryption Standard algorithm, double and triple DES, IDEA, Advance encryption standard, comparison of block ciphers, differential and linear cryptanalysis. Public key encryption : Overview of symmetric key cryptography, RSA algorithm, EIGmal encryption, Knapsack encryption algorithm. public key cryptography standard (PKCS), PKI and security. UNIT-IV Message and Users authentication : One way hash functions, message digest, MD5 algorithm, secure hash algorithm (SHA1), comparison between different message digest algorithm, message authentication code. Users authentication : authentication basics, password, authentication tokens, certificate based authentication, biometric authentication, Kerberos, Single sign on approach. UNIT-V Digital signature: digital envelope, classification of digital signature schemes – appendix and message recovery, attacks on signature. Key management techniques: simple key establishment models, tradeoffs among key establishing protocols, techniques for distributing confidential key, techniques for distributing public keys, comparison of techniques for distributing public keys, key management involving multiple domains, key management life cycle. Text/Reference Books 1. Applied cryptography – Menezes, Oorschot and Vanstone 2. Network Security Essentials - William Stallings
