Instruction Stream Mutation for Non-Deterministic ProcessorsJ. Irwin, D. Page, N. P. Smart, Instruction Stream Mutation for Non-Deterministic Processors. CSTR-01-008, Department of Computer Science, University of Bristol. December 2001. PDF, 120 Kbytes.
Differential power analysis (DPA) has become a real-world threat to the security of cryptographic hardware devices such as smart-cards. By using cheap and readily available equipment, attacks can easily compromise algorithms running on these devices in a non-invasive manner. Adding non-determinism to the execution of cryptographic algorithms has been proposed as a defence against these attacks. One way of achieving this non-determinism is to introduce random additional operations to the algorithm which produce noise in the power profile of the device. We describe the addition of a specialised processor pipeline stage which increases the level of potential non-determinism and hence guards against the revelation of secret information.