On the Correctness of an Approach against Side-Channel Attacks

摘要

Side-channel attacks are a very powerful cryptanalytic technique. Li and Gu [ProvSec'07] proposed an approach against side-channel attacks, which states that a symmetric encryption scheme is IND-secure in side-channel model, if it is IND-secure in black-box model and there is no adversary who can recover the whole key of the scheme computationally in side-channel model, i.e. WKR-SCA ∧ IND → IND-SCA. Our researches show that it is not the case. We analyze notions of security against key recovery attacks and security against distinguishing attacks, and then construct a scheme which is WKR-SCA-secure and IND-secure, but not IND-SCA-secure in the same side-channel environment. Furthermore, even if the scheme is secure again partial key recovery attacks in side-channel model, this approach still does not hold true.