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Details of Grant 

EPSRC Reference: EP/E001556/1
Title: Reassessing Processor Design Assumptions in Cryptography
Principal Investigator: May, Professor D
Other Investigators:
Eder, Professor K Page, Dr D
Researcher Co-Investigators:
Project Partners:
Department: Computer Science
Organisation: University of Bristol
Scheme: Standard Research
Starts: 21 December 2006 Ends: 20 June 2010 Value (£): 386,437
EPSRC Research Topic Classifications:
Fundamentals of Computing System on Chip
EPSRC Industrial Sector Classifications:
Related Grants:
Panel History:  
Summary on Grant Application Form
The design of computer processors is based on many years of research andunderpins the performance of most other areas of Computer Science. One canroughly split processor designs into two groups: general purpose, which arecapable of being programmed for any task, and special purpose, which arelimited to one task only. The trade-off between the two approaches is thatspecial purpose processors generally deliver higher performance or smallersize and power budgets because they can focus on one particular task and notworry about needing to execute the others.Special purpose processors are attractive in cryptography. Cryptographicalgorithms are representative of a domain which uses specialist data typesand operations and demands high performance. However, cryptography is a fastmoving field and if a cryptographic algorithm is found to be weak, it needsreplacing quickly to avoid breaches in security. This need for algorithmagility negates the benefit of special purpose processors. Therefore, if ageneral purpose processor were able to deliver the required performance itwould be a better choice since it could simply be reprogrammed to run a newalgorithm rather than simply discarded.Like most aspects of computer architecture, successful general purposeprocessor designs rely heavily on selecting an effective trade-off betweenmany competing factors. Such decisions are typically resolved by performinga workload characterisation of the sorts of algorithm that the processor willexecute. By considering an average program, the architecture is designed sothat the average case is optimised while non-typical cases are marginalisedor omitted. A quarter century after many design decisions and assumptionswere made by the pioneers of the field, we are still using largely similardesigns. One expects that such decisions were initially made using a mix ofresearch and common sense based on prevailing technologies of the time.Despite the success of these assumptions, the technology landscape has nowchanged radically: the types of algorithm we execute today are differentand many of the constraints which guided initial thinking have disappeared.We claim that current general purpose processor design is based on entrenchedassumptions that are limiting their flexibility and long term viability forexecuting a wide range of algorithms. The crux of our proposed research isthe reassessment of such assumptions and investigation of alternativeapproaches using cryptography algorithms as an example domain. We aim, throughrelatively minor and non-disruptive alterations in design which lie outsidecurrent thinking, to deliver a high performance platform for cryptographicalgorithms while allowing algorithm agility: essentially delivering the bestof both world from general and special purpose processor design.
Key Findings
Potential use in non-academic contexts
Date Materialised
Sectors submitted by the Researcher
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Organisation Website: http://www.bris.ac.uk