Department of Computer Science, Unit Catalogue 2011/12 

Credits:  6 
Level:  Honours (FHEQ level 6) 
Period: 
Semester 2 
Assessment:  EX 100% 
Supplementary Assessment:  CM30173 Mandatory Extra Work (where allowed by programme regulations) 
Requisites:  Before taking this unit you must take CM10196 and take CM20217 and take CM20218 or have an elementary knowledge of number theory, as in chapters 12 of Davenport The Higher Arithmetic, or CM10139 Computation 1: numbers & structures and 20144, or MA10001 Numbers (and for transitional arrangements an elementary knowledge of number theory, as in chapters 12 of Davenport The Higher Arithmetic, or CM10139 Computation 1: numbers & structures and 20144, or MA10001 Numbers). 
Description:  Aims: To introduce students to the techniques, tools and pitfalls of cryptography (including authentication etc.). Learning Outcomes: 1. Students will understand the basic mathematics behind privatekey and publickey cryptography; 2. Students will be able to describe several wellknown techniques for cryptographic security and authentication. Skills: Application of Number (T/F, A), Problem Solving (T/F). Content: Introduction to the problem: security, privacy, authentication, repudiation, revocation. The key distribution problem: public vs private keys. The mathematics of cryptography: FermatEuler Theorem, structure of finite fields and elliptic curves. Cryptographic algorithms: DiffieHellman, RSA, ElGamal. Cryptanalysis: discrete logarithms, factoring. The Coppersmith attack. Elliptic Curve analogues. Privatekey algorithms: DES, 3DES and AES. Common hashing algorithms: MD5, SHA1. Characteristics of safe keys. Using cryptography: digital signatures: how to find the public key.Repudiation and revocation, examples in practice: PGP, digital certificates. 
Programme availability: 
CM30173 is Optional on the following programmes:Department of Computer Science
