An Implementation of DES and AES, Secure against Some Attacks

Abstract

Abstract. Since Power Analysis on smart cards was introduced by Paul Kocher [7], many countermeasures have been proposed to protect implementations of cryptographic algorithms. In this paper we propose a new protection principle: the transformed masking method. We apply this method to protect two of the most popular block ciphers: DES and the AES Rijndael. To this end we introduce some transformed S-boxes for DES and a new masking method and its applications to the non-linear part of Rijndael.

A Vector Approach to Cryptography Implementation

“…Another big advantage with our approach is that robust software countermeasures (like those described in [2]) can be implemented to compensate for any side-channel information leakage.…”

“…For security, counter-measures have been proposed, most of which are software-based leading to bulkier codes and slower programs. A hardware-software co-design approach is being undertaken by other researchers [2,3,4] in order to have a hardware that would reduce the cost of those software counter-measures.…”

Provably Secure S-Box Implementation Based on Fourier Transform

“…The first attack consists in directly interpreting power consumption measurements and the second attack also involves statistical tests. From then on, many papers describing either countermeasures or attack improvements have been published (see [1,4,6,21] for example).…”

“…the calls to the S-Boxes). Indeed, all the other operations are more or less linear and can be protected in a straightforward manner (see [1] for instance). To protect the calculus of the output of an S-Box against DPA, three main kinds of methods have been proposed in the literature.…”

“…Then, the computation can be securely carried out by performing calculations with these random blocks. The second method, called the re-computation method [1,2,29], involves a recomputation of the lookup tables corresponding to the S-Box with one or several random value(s) which must be changed each time the algorithm is executed. The third generic method, that we call here S-Box secure calculation, has been essentially applied to protect AES implementations [5,15,28,32] due to the strong algebraic structure of the AES S-Box.…”