PhD/Doctoral Studentships

Start Date: September/October 2014

End Date: March/April 2018

The Government Communications Headquarters (GCHQ) in Cheltenham has agreed in principle to sponsor two PhD/Doctoral Studentships at Bristol University in the area of Cryptography.

The studentships are only open to UK nationals and the successful candidate will be required to spend in the region of 2 - 4 weeks per year at GCHQ headquarters in Cheltenham. To be considered for this studentship, candidates must therefore be prepared to undergo GCHQ's security clearance procedures.

The studentships will be funded for a period of 3.5 years. GCHQ will cover the costs of university fees (currently £ 3828 per annum) and will provide an annual stipend to the student corresponding to the National Minimum Stipend (currently £ 13,590 per annum) plus an additional stipend of £ 7,000 per annum. Making a total tax-free stipend of £ 20,590 per annum. A generous travel budget is also provided to enable attendance at international conferences and workshops.

The two studentships will be in the following areas:

Title: Secure Application Programming Interfaces for Key

Supervisor: Bogdan Warinschi

Cryptographic key management is pervasive in real-life use of cryptography where it is often used to implement various security policies. Unfortunately, the relation between key-management and policy enforcement is not well-understood, especially when modern cryptographic primitives like attribute-based encryption are employed. This project aims to produce rigorous foundations for the study of the relation and integration between key-management and security policy enforcement with a particular focus on key-management APIs.

We expect a candidate to have at least a strong 2:1 degree in Mathematics or Computer Science, be able to program proficiently, and be comfortable with mathematical proofs. Prior knowledge of cryptology or a security-related field is not essential.

For further details contact Bogdan Warinschi (bogdan (at)

Title: Game Theory of Cryptographic Threat Mitigation

Supervisors: Nigel Smart and David Leslie

Rivest and others have recently introduced the game of FlipIt to model the case of persistent attacks against a single server or service. The game, whilst surprisingly simple, turns out to be surprisingly hard to mathematically model via game theory. In this project we aim to extend and analyse the FlipIt game in the case of multiple servers working together in a threshold (or other) manner to defend a multi-server application. The project will use a game-theoretical approach to investigate and analyse various attack and defence strategies in this extension.

We expect a candidate to have at least a strong 2:1 degree in Mathematics or Computer Science. Prior knowledge of cryptology or a security-related field is not essential, but prior exposure to game theory and/or stochastic processes is desirable.

For further details contact Nigel Smart (nigel (at) or David Leslie (david.leslie (at)

Due to the additional requirement of security clearance, applicants to either position are advised to send in their application as soon as possible.

To apply please visit the web page

Your application should state which project you are interested in.