Module manager: Prof Steven Noble
Email: S.D.Noble@leeds.ac.uk
Taught: Semester 1 (Sep to Jan) View Timetable
Year running 2026/27
COMP3223, COMP3911
This module is not approved as a discovery module
Cryptography is a science that ensures the secure exchange of information in the modern world. It focuses on protecting information from unauthorised access, ensuring confidentiality, integrity, and authenticity in communication. You will explore the mathematics behind cryptosystems, from early ciphers and Enigma machines to modern symmetric and public-key cryptosystems. Through the lens of real-world secure systems—covering hardware and software platforms where cryptography is applied—you will see how these principles are implemented to protect data in practice. Practical components will include case studies of common exploits, security & risk analysis allowing you to analyse vulnerabilities and understand how cryptography can be used to provide a defence. You will also gain hands-on experience implementing cryptographic solutions using appropriate programming languages, for applications such as secure elections and digital currencies. The module also considers privacy, addressing legislative frameworks, ethical considerations, and human factors that affect secure practice. You will examine how legal requirements and user behaviour intersect with cryptographic protections in real-world systems, highlighting the broader societal and organisational context of information security.
The main aim of the module is to provide a broad introduction to modern techniques used to ensure the security of information and platforms. Students will develop sufficient proficiency in the underlying mathematics to calculate confidently within the relevant mathematical structures and to understand how their properties underpin the correct operation of cryptosystems. The module also addresses the practical challenges involved in implementing these systems and explores how they are overcome in real-world applications. Through the use of appropriate software libraries, students will experiment with both the foundational mathematics and concrete examples of cryptosystems.
On successful completion of the module students will be able to:
apply a comprehensive knowledge of mathematics, statistics, natural science and engineering principles to the solution relating to cryptography and secure systems. (C1)
select and critically evaluate technical literature and other sources of information to solve complex problems. (C4)
design solutions for complex problems that evidence some originality and meet a combination of societal, user, business and customer need as appropriate. (C5)
apply an integrated or systems approach to the solution of complex problems. (C6)
evaluate the environmental and societal impact of solutions to complex problems and minimise adverse impacts. (C7)
identify and analyse ethical concerns and make reasoned ethical choices informed by professional codes of conduct. (C8)
adopt a holistic and proportionate approach to the mitigation of security risks. (C10)
select and use practical laboratory and workshop skills to investigate complex problems and be able to comment on their limitations. (C12, C13)
communicate effectively on complex engineering matters with technical and non-technical audiences, evaluating the effectiveness of the methods used. (C17)
reflect on their level of mastery of subject knowledge and skills and plan for personal development. (C18)
On successful completion of the module students will be able to:
Accurately communicate mathematical and computational ideas in written form. (WR1, ES1, AS3, AS4)
Apply critical thinking to assess the strengths and weaknesses of cryptosystems and codes. (WR2, SS2, AS2)
Creatively combine computational techniques to, for example, attack historic cryptosystems. (WR4, WR10, SS9, ES4)
Describe the requirements of cryptographic and coding tools within a variety of IT domains. (DS1, DS2)
Successfully complete a small project, producing a coherent piece of work. (WR8, WR9, WR13, SS7, ES6, ES8, ES9, AS5, AS6, AS8, AS9)
Historical cryptosystems and cryptanalysis attacks: Single-character substitution ciphers, frequency analysis, Hill cipher, Vigenère cipher
Kasiski test, index of coincidence -test, Enigma.
Current cryptosystems: symmetric systems, asymmetric systems.
Digital signatures: algorithms, hash functions, collisions.
Future challenges in cryptography & security: post quantum cryptography, AI powered cyberattacks, supply chain attacks, cloud security.
Hardware enabling cryptography, architectural patterns for secure systems, Programming libraries for working with cryptosystems.
Ethical, social and legal topics relating to cryptography and security.
| Delivery type | Number | Length hours | Student hours |
|---|---|---|---|
| Lectures | 22 | 2 | 44 |
| seminars | 16 | 1 | 16 |
| Practicals | 3 | 2 | 6 |
| Private study hours | 134 | ||
| Total Contact hours | 66 | ||
| Total hours (100hr per 10 credits) | 200 | ||
Check the module area in Minerva for your reading list
Last updated: 30/04/2026
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