SCRAMBLED TWEAK MODE OF BLOCKCIPHERS FOR DIFFERENTIAL POWER ANALYSIS RESISTANT ENCRYPTION

摘要

A system and method for providing a scrambled tweak mode of block cipher encryption for a device that mitigates the effect of side channel attacks based on differential power analysis (DPA). The scrambled tweak mode encryption engine creates noise at the start of the encryption process by obfuscating the counter value with the use of the very fast mixing function, such as a mixing function based on a XOR tree, substitution-permutation networks, or double-mix Feistel networks. The mixing function uses some secret key material, which diversifies its behavior between different instantiations. Because the counter values are scrambled and the mixing functions operate very fast in parallel hardware, the input of the block cipher is pseudorandom and groups of blocks can't be correlated.

主权项

1. A system for improving security of a device comprising:
a first mixing unit that scrambles a first initial value for a first segment of data; and a first block cipher operating in a tweak mode that encrypts the first segment of data to produce a first ciphertext message from a first plaintext message; wherein the scrambled first initial value is XORed to the input and output of the first block cipher.