An introduction to cryptography and security mechanisms


This module is intended to be both relevant and relatively timeless. It is easy to present a module on cryptography that is quickly out of date.

Topics covered

  • Fundamental principles: This module is intended to be just as relevant in ten years time as it would have been relevant ten years ago. This is because it is primarily concerned with the fundamental principles rather than technical details of current technology.
  • Application-focussed:This module is primarily concerned with the cryptography that a user or practitioner of information security needs to know. While there is a great deal of contemporary theoretical research on cryptography, few of these ideas make it through to real-world applications, which tend to deploy only well-tested and understood techniques. This module focuses on cryptography for everyday applications.
  • Widely accessible: This module is intended to be suitable as a first introduction to cryptography. It focuses on core issues and provides an exposition of the fundamentals of cryptography. This module is intended to be introductory, self-contained and widely accessible. Students completing this module should not expect to be able to design algorithms

Learning outcomes

If you complete the module successfully, you should be able to:

  • understand of the use of, and services provided by, the main types of cryptographic scheme.
  • appreciate of the need for good key management. This will include an appreciation of the general nature of: encryption techniques for providing confidentiality services (including stream ciphers, block ciphers and public key techniques), mechanisms for providing data integrity and origin authentication, including MACs and digital signatures, message exchanges to provide entity authentication and/or key establishment, and the use of Trusted Third Parties, such as Certification Authorities (CAs), to provide and support Public Key infrastructures.


This module is assessed by a two-hour unseen written examination (75%) and a written assignment (25%).

Essential reading

  • Everyday Cryptography (Martin.)