Improved Differential Fault Analysis on Block Cipher SEED-128

SEED is a 128-bit block cipher supporting 128, 192 and 256-bit secret keys. It has been adopted as a national industrial association standard (TTAS KO-12.0004) at 1999 and ISO/IEC 18033-3 and IETF RFC 4269 at 2005. The first cryptanalytic result on DFA is proposed in 2004. After that Jeong et al. proposed DFAs on SEED-128/192/256. In these attacks, an attacker can induce 1-bit random fault to input registers of the last G function in the target round. In this assumption, he can recover the secret key by using 48, 72 and 96 fault injections for SEED-128/192/256, respectively. In this paper, we propose improved differential fault attack on SEED-128. In our attack, it is assume that an attacker can induce 1-byte random fault to input registers of the second G function in the target round. By using only 4 fault injections, the proposed attack can recover the secret key of SEED-128 on average 1 minute.