Abstract: As microprocessors and other electronic devices become faster and employ higher component densities, the noise generated by the transitions between data states has an increasing influence on the performance and security of these devices. Calculations and processes performed with the method of the invention will have a constant number of bit transitions, so ground bounce and similar effects are minimized. In the preferred embodiment, this is done by replacing leaky software processes with lookup tables filled with output data corresponding to outputs of a software process indexed with corresponding operand values. The invention is particularly useful in smart card implementations using DES (data encryption standard) protection, which may be cracked by monitoring the power signature while data is being processed.

Abstract: New techniques for cracking sealed platforms have recently been discovered which observe power modulation during execution of a software encryption program on a computer processor. Particularly vulnerable to such simple power analysis and differential power analysis attacks are smart cards which employ Data Encryption Standard (DES) protection. The invention protects against such attacks by substantively altering the observable operation of the cryptographic algorithm while it is processing input data. The alterations are generated in a random way and may include average neutral execution, permuted execution or code padding of the cryptographic algorithm.