Dorian L Snell

US Patent:

20030223580, Dec 4, 2003

Filed:

May 23, 2003

Appl. No.:

10/445110

Inventors:

Dorian Snell - Colorado Springs CO, US

International Classification:

H04L009/00

US Classification:

380/028000

Abstract:

A cryptographic method and related implements the Rijndael—AES encryption standard. In one improvement, the decryption round keys are generated on a round by round basis from the final Nk round keys saved from a previous encryption key scheduling operation. Latency and memory requirements are thereby minimized. S-boxes for the AES key generation and cipher operation itself, may be implemented multiple times in different ways with different power signatures, with a pseudo-random selection of the pathway for the different bytes to be substituted. The premix operation occurs simultaneously with the generation of first round keys, and a dummy circuit with substantially identical timing as the real premix circuitry adds power consumption noise to the premix.