Address-Bit Differential Power Analysis of Cryptographic Schemes OK-ECDH and OK-ECDSA

The differential power analysis (DPA) is a powerful attack against the implementation of cryptographic schemes on mobile devices. This paper proposes an alternative DPA using the addresses of registers of elliptic curve based cryptosystems (ECC) implemented on smart cards. We call the analysis the address-bit DPA in this paper. The analysis was originally investigated by Messerges, Dabbish and Sloan, however it was thought to be of no effect if the intermediate data are randomized. We extend the analysis and show how the extended analysis works against scalar exponentiations even if the implementation is resistant against the data-based DPA. We show experimental results of our analysis of cryptographic schemes OK-ECDH and OK-ECDSA, which are candidates of the CRYPTREC project in Japan, and evidence of their weakness.