CSL 863: Spl Topics in TCS (Cryptography) Semester II 2008-2009 Instructor : Sandeep Sen Co-Instructor: Prof Palash Sarkar (ISI, Kolkata)

Lectures:

Even Week (starting Jan 12) Mon 2:15pm , Fri 2-3p

Venue : CSE Seminar Room IIA 501

Course Outline

Introduction and information theoretic background: (3 hrs)
	cryptography and cryptanalysis, 
	historical examples;
	notions of entropy, equivocation, perfect secrecy, unicity distance.

Symmetric key cryptography: (12 hrs)
	block cipher design -- Feistel network, advanced encryption standard
(AES);
	modes of operations; 
	stream cipher design techniques;
	methods of cryptanalysis -- linear and differential attacks;
	collision resistant hash functions;

Complexity theoretic notions: (6 hrs)
	one-way functions;
	trapdoor one-way functions;
	pseudorandom generators;
	pseudorandom functions and permutations.

Brief introduction to number theory: (9 hrs) 
	number theory -- Euclidean algorithm, Euler's totient, Chinese
remainder theorem, 
			 primitive roots, quadratic residues;
	elliptic curves over finite fields;
	methods for exponentiation and scalar multiplication.

Public key cryptography: (12 hrs)
	Diffie-Hellman key agreement;
	ElGamal and RSA public key cryptosystem;
	digital signatures;
	formal security definitions.
	primality testing and factoring;
	algorithms for discrete log problem;

Organization:

Reference books

Handouts given in class
Online Notes (modular arithmetic and primality)

Slides on Public key encryption

Slides on Identity based encryption

Slides on cyclic group based discrete log

Assignment 1

 (from Stinson) Chapter 2: 2.2, 2.5, 2.6, 2.18, 2.19, 2.20.
Chapter 3: 3.2, 3.4, 3.9.

(relevant pages describing the problems are kept with the notes)

Marks

Provisional Grades