(Created 2008-07-17.)
 CRYPTOGRAPHY EDI051

Higher education credits: 7,5. Grading scale: TH. Level: G2 (First level). Language of instruction: The course will be given in Swedish. Optional for: C4, C4ks, C4sd, D4, D4ks, E4, E4ks, F4, MWIR2, Pi4, RH4. Course coordinator: Professor Thomas Johansson, thomas@it.lth.se, Inst för elektro- och informationsteknik. Recommended prerequisits: A first course in programming, (e.g. EDA011 or EDA016 ). Assessment: Written exam and four mandatory small projects. Home page: http://www.eit.lth.se/course/edi051.

Aim
This course is intended to be an introduction to the fascinating subject of cryptography. It provides both a firm ground in the fundamentals and a feel for the subject for anyone interested either in carrying out cryptographic research or employing cryptographic security.

Knowledge and understanding
For a passing grade the student must

• be able to describe different building blocks used in cryptology,

• be able to describe the general problems that are addressed by cryptology,

• be able to explain the principles behind different cryptographic primitives.

Skills and abilities
For a passing grade the student must

• be able to provide descriptions of how cryptographic primitives can be used in security systems.

• be able to show that you are capable to choose suitable parameters to cryptographic primitives as well as analyze various constructions from a security perspective.

During the course you have to present and discuss your knowledge through exercises and several smaller mandatory projects.

Contents
Classical cryptography: Introduction and basic notation, The Caesar cipher, simple substitution, polyalphabetic ciphers (Vigenére, Kasiskis method, Vernam), transposition ciphers, rotor machines (Enigma).

Shannons theory of secrecy: entropy, key and message equivocation, redundancy, unicity distance, perfect secrecy.

Shift register theory and stream ciphers: Finite fields, linear feedback shift register sequences, periods and cycle sets, shift register synthesis, nonlinear combinations of sequences, attacks on stream ciphers.

Block ciphers: Data Encryption Standard (DES), Advanced Encryption Standard (AES).

Public key cryptography: Basic number theory, RSA, Diffie-Hellman key exchange, factoring, primality, digital signatures.

Authentication codes: Impersonation and substitution attacks.

Secret sharing: Shamirs threshold scheme, general secret sharing, perfect and ideal schemes.

Projects: 1. Factoring. 2. Correlation attacks. 3. Shift register sequences. 4. Block ciphers.

Literature
Lecture notes in cryptology (distributed through the department).
Alternative literature: Stinson, D., Cryptography, Theory and Practice, CRC Press, ISBN 1-58488-206-9 or Smart, N., Cryptography: An Introduction, McGraw-Hill, ISBN 0077099877.