Side channel analysis attacks using AM demodulation on commercial smart cards with SEED

We investigate statistical side channel analysis attacks on the SEED block cipher implemented in two commercial smart cards used in a real-world electronic payment system. The first one is a contact-only card and the second one is a combination card. Both cards have no masking scheme at algorithm level and the combination card supports only hiding techniques in hardware level. Our results show that an unprotected implementation of SEED allows one to recover the secret key with low number of power or electromagnetic traces. Moreover, this paper clearly confirms that, although hiding countermeasures such as random current and random noise may increase the number of power traces needed for a successful attack, it is difficult to provide sufficient resistance to side channel attacks for itself. We believe that our results in this research will also be beneficial to the analysis and protection of other algorithms and commercial smart cards.

► We investigate statistical side channel analysis attacks on the SEED block cipher implemented in commercial smart cards used in a real-world electronic payment system.
► Our results show that an unprotected implementation of SEED allows one to recover the secret key with low number of power or electromagnetic traces.
► This paper shows that, although hiding countermeasures such as random current and random noise may increase the number of power traces needed for a successful attack, it is difficult to provide sufficient resistance to side channel attacks for itself.