Course

Unit 1

Introduction and Classic Encryption Techniques: OSI security architecture, Security attacks – Passive attacks, Active attacks, Security services- Authentication, Access Control, Data Confidentiality, Data integrity, Nonrepudiation, Availability service. Model for network security. Symmetric cipher model, Cryptography, Cryptoanalysis, Substitution techniques- Hill Cipher, One time pad, Transposition Techniques. Finite Fields: Groups, Rings and Fields, Modular arithmetic, Euclidian algorithm, Finite Fields of the form GF(p), Polynomial arithmetic.

Unit 2

Block Ciphers. Data Encryption Standard, AES Cipher: Block Cipher Principles – Stream Ciphers and Block Ciphers, Feistel Cipher, Feistel Decryption algorithm, The Data encryption standard, DES Decryption – Avalanche effect, The AES Cipher, substitute bytes transformation, Shift row transformation, Mix Column transformation.

Unit 3

Public Key Cryptography, RSA and Key Management: Principles of public key cryptosystems-Public key cryptosystems, Application for Public key cryptosystem requirements, Fermat’s theorem, Euler’s Totient Function, Euler’s theorem, RSA algorithm, Key management, Distribution of public keys, Publicly available directory, Public key authority, public key certificates, Distribution of secret keys using public key cryptography. Message Authentication and Hash Function: Authentication requirements, Authentication functions- Message Encryption, Public Key, Encryption, Message Authentication Code, Hash function.

Pre Requisite(s): Nil

Course Objectives

• To provide foundation in network security and defense mechanisms.
• To provide modeling skill on encryption and decryption of data.
• To provide mathematical bases on encryption of data and with its applications.

Course Outcomes

• CO1: Able to understand network security services and mechanisms and the types of attacks they are designed for
• CO2: Able to Model the symmetric encryption process and different encryption techniques
• CO3: Able to apply the concepts of group, ring, field, modular arithmetic, Euclidean algorithm, Finite fields and polynomial arithmetic
• CO4: Illustrate the principles of modern symmetric ciphers like the Data Encryption Standard and Advanced Encryption Standard.

CO – PO Mapping

Text Book(s)

1. William Stallings, Cryptography and Network security: principles and practice”, 4th Edition, Prentice Hall of India, New Delhi, 2006

Reference(s)

1. Behrouz A. Forouzan, Cryptography and Network security Tata McGraw-Hill, 2008
2. David S. Dummit& Richard M Foote, Abstract Algebra, 2nd Edition, Wiley India Pvt. Ltd.,2008.
3. Douglas A. Stinson, Cryptography, Theory and Practice, 2/e, Chapman & Hall, CRC PressCompany, Washington, 2005.
4. Lawrence C. Wahington, Elliptic Curves: Theory and Cryptography, Chapman & Hall, CRCPress Company, Washington, 2008.
5. N. Koeblitz: A course in Number theory and Cryptography, 2008
6. Thomas Koshy: Elementary Number Theory with Applications, 2/e, Academic Press, 2007
7. Tyagi and Yadav, Cryptography and network security, Dhanpatrai, 2012