## CM30173: Cryptography

[Page last updated: 27 September 2022]

Owning Department/School: Department of Computer Science
Credits: 6 [equivalent to 12 CATS credits]
Notional Study Hours: 120
Level: Honours (FHEQ level 6)
Period:
Semester 2
Assessment Summary: EX 100%
Assessment Detail:
• Examination (EX 100%)
Supplementary Assessment:
Like-for-like reassessment (where allowed by programme regulations)
Requisites: An elementary knowledge of number theory, as in chapters 1-2 of Davenport The Higher Arithmetic, is required to take this unit.
Before taking this module you must ( take CM10227 OR take XX10190 OR take MA10265 OR take MA10275 OR take MA10276 ) AND ( take CM20217 OR take MA10209 )
Learning Outcomes: 1. Students will understand the basic mathematics behind private-key and public-key cryptography;
2. Students will be able to describe several well-known techniques for cryptographic security and authentication.

Aims: To introduce students to the techniques, tools and pitfalls of cryptography (including authentication etc.).

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: Fermat-Euler Theorem, structure of finite fields and elliptic curves. Cryptographic algorithms: Diffie-Hellman, RSA, El-Gamal. Cryptanalysis: discrete logarithms, factoring. The Coppersmith attack. Elliptic Curve analogues. Private-key algorithms: DES, 3DES and AES. Common hashing algorithms: MD5, SHA-1. 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
• USCM-AFB06 : BSc(Hons) Computer Science (Year 3)
• USCM-AAB07 : BSc(Hons) Computer Science with Study year abroad (Year 4)
• USCM-AKB07 : BSc(Hons) Computer Science with Year long work placement (Year 4)
• USCM-AFB27 : BSc(Hons) Computer Science and Artificial Intelligence (Year 3)
• USCM-AFB20 : BSc(Hons) Computer Science and Mathematics (Year 3)
• USCM-AAB20 : BSc(Hons) Computer Science and Mathematics with Study year abroad (Year 4)
• USCM-AKB20 : BSc(Hons) Computer Science and Mathematics with Year long work placement (Year 4)
• USCM-AFM01 : MComp(Hons) Computer Science (Year 3)
• USCM-AAM02 : MComp(Hons) Computer Science with Study year abroad (Year 3)
• USCM-AKM02 : MComp(Hons) Computer Science with Year long work placement (Year 3)
• USCM-AFM27 : MComp(Hons) Computer Science and Artificial Intelligence (Year 3)
• USCM-AAM27 : MComp(Hons) Computer Science and Artificial Intelligence with Study year abroad (Year 3)
• USCM-AKM27 : MComp(Hons) Computer Science and Artificial Intelligence with Year long work placement (Year 3)
• USCM-AFM14 : MComp(Hons) Computer Science and Mathematics (Year 3)
• USCM-AAM14 : MComp(Hons) Computer Science and Mathematics with Study year abroad (Year 3)
• USCM-AKM14 : MComp(Hons) Computer Science and Mathematics with Year long work placement (Year 3)
Department of Mathematical Sciences
• USMA-AFB15 : BSc(Hons) Mathematical Sciences (Year 3)
• USMA-AAB16 : BSc(Hons) Mathematical Sciences with Study year abroad (Year 4)
• USMA-AKB16 : BSc(Hons) Mathematical Sciences with Year long work placement (Year 4)
• USMA-AFB13 : BSc(Hons) Mathematics (Year 3)
• USMA-AAB14 : BSc(Hons) Mathematics with Study year abroad (Year 4)
• USMA-AKB14 : BSc(Hons) Mathematics with Year long work placement (Year 4)
• USMA-AFB01 : BSc(Hons) Mathematics and Statistics (Year 3)
• USMA-AAB02 : BSc(Hons) Mathematics and Statistics with Study year abroad (Year 4)
• USMA-AKB02 : BSc(Hons) Mathematics and Statistics with Year long work placement (Year 4)
• USMA-AFB05 : BSc(Hons) Statistics (Year 3)
• USMA-AAB06 : BSc(Hons) Statistics with Study year abroad (Year 4)
• USMA-AKB06 : BSc(Hons) Statistics with Year long work placement (Year 4)
• USMA-AFM14 : MMath(Hons) Mathematics (Year 3)
• USMA-AFM14 : MMath(Hons) Mathematics (Year 4)
• USMA-AAM15 : MMath(Hons) Mathematics with Study year abroad (Year 4)
• USMA-AKM15 : MMath(Hons) Mathematics with Year long work placement (Year 4)
• USMA-AKM15 : MMath(Hons) Mathematics with Year long work placement (Year 5)

 Notes: This unit catalogue is applicable for the 2022/23 academic year only. Students continuing their studies into 2023/24 and beyond should not assume that this unit will be available in future years in the format displayed here for 2022/23. Programmes and units are subject to change in accordance with normal University procedures. Availability of units will be subject to constraints such as staff availability, minimum and maximum group sizes, and timetabling factors as well as a student's ability to meet any pre-requisite rules. Find out more about these and other important University terms and conditions here.