Complete SCARE of AES-Like Block Ciphers by Chosen Plaintext Collision Power Analysis
Résumé
Despite Kerckhoffs's principle, proprietary or otherwise secret cryptographic algorithms are still used in real life. For security and efficiency reasons a common design practice simply modifies some parameters of widely used and well studied encryption standards. In this paper, we investigate the feasibility of reverse engineering the secret specifications of an AES-like block cipher by SCARE techniques based on collision power analysis. In the considered observational model, we demonstrate that an adversary who does not know the secret key can recover the full set of secret parameters of an AES-like software implementation even if it is protected by common first-order Boolean masking and shuffling of independent operations. We study possible countermeasures and recall some simple guidelines to mitigate the side-channel information with the aim to thwart our attacks.