Introductory description

Secure systems aim to create a trusted environment that protects sensitive data, maintains system functionality, and mitigates risks associated with unauthorized access, data breaches, and other security threats. The goal of a secure system is twofold: to ensure the protection and integrity of information and resources by enabling authorized and desired actions while preventing unauthorized access, malicious activities, and undesirable incidents. However, achieving this goal poses significant challenges. These challenges include defining which events are acceptable and which are not, predicting future possibilities, and determining the system's boundaries. Notwithstanding these challenges, there exist established approaches to constructing secure systems that provide robust protection and maintain system functionality while minimising the occurrence of unwanted incidents. Cryptography plays a crucial role in achieving these goals. It is an essential tool that allows us to protect information and ensure confidentiality, integrity, and authentication. It provides mechanisms to protect sensitive information, verify the identity of users and devices, and enable secure communication over unsecured networks. Cryptographic techniques, such as symmetric-key and public-key cryptography, are used in various contexts including secure messaging, online transaction protection, and virtual private networks (VPNs). This module introduces concepts of cryptography and explores how they are practically applied to ensure strong security measures in secure systems.

Module aims

Outline syllabus

This is an indicative module outline only to give an indication of the sort of topics that may be covered. Actual sessions held may differ.

Outline content
The content of this module will be taught from a cyber security perspective.

Symmetric Key Cryptography:

• Block ciphers (e.g., DES, AES)
• Stream ciphers (e.g., RC4)
• Modes of operation (e.g., ECB, CBC, CTR)
• Key management and distribution
• Message authentication codes
• Key derivation functions

Public-Key Cryptography:

• RSA algorithm
• Diffie-Hellman key exchange
• Elliptic Curve Cryptography
• Digital signatures (e.g., RSA, DSA)
• Key exchange protocols (e.g., SSL/TLS, SSH)

Hash Functions and Message Digests:

• Cryptographic hash functions (e.g., SHA-256, MD5)
• Applications of hash functions (e.g., password storage, data integrity)
• Message Digest algorithms (e.g., HMAC)

Cryptographic Protocols and Applications:

• Secure communication protocols (e.g., SSL/TLS, IPsec)
• Secure email (e.g., PGP)
• Virtual Private Networks
• Secure File Transfer (e.g., SSH, SCP)

Cryptographic Attacks and Countermeasures:

• Cryptanalysis techniques, Side-channel attacks etc.
• Key management and secure key storage
• Random number generation
• Cryptographic standards and certifications

Applied Cryptography in Real-World Systems:

• Encryption in storage systems
• Access control
• Blockchain technology
• Privacy-enhancing technologies (e.g., homomorphic encryption)

Cryptographic Tools:

• Introduction to cryptographic libraries (e.g., OpenSSL)
• Practical implementation of cryptographic algorithms

Legal and Ethical Aspects:

• Cryptography policies and regulations
• Ethical considerations in cryptography
• Cryptography and privacy laws

Design and development of cryptosystems

The future of cryptography

Learning outcomes

By the end of the module, students should be able to:

• Design a security architecture that satisfies the security needs of a given scenario.
• Configure systems, applying cryptographic techniques as needed, to achieve desired security objectives.
• Develop secure cryptosystems by effectively utilizing programming languages and cryptographic tools to implement cryptographic operations.
• Analyse the suitability of cryptographic algorithms to meet specific security requirements, evaluating their security properties, strengths, and limitations.

Indicative reading list

Wong, D. (2021). Real-World Cryptography. Manning Publications.
Schneier, B., Kohno, T., & Ferguson, N. (2013). Cryptography Engineering: Design Principles and Practical Applications. Wiley.
Stallings, W. (2016). Cryptography and Network Security: Principles and Practice (7th ed.). Pearson.
Bray, S. W. (2020). implementing cryptography using Python. John Wiley & Sons.

Interdisciplinary

Cryptography is an inherently interdisciplinary subject. It combines ideas from mathematics and computer science together with social studies on the usability of secure systems, and these will be demonstrated throughout the module.

Subject specific skills

This module enables students to develop an understanding of the fundamentals of cryptography, knowledge of cryptographic algorithms and when to use them, as well as an ability to use cryptography to build secure systems.

Transferable skills

Critical thinking, problem solving, written communication, and presentation skills