Fault Analysis of the KTANTAN Family Block Ciphers: A Revisited Work of Fault Analysis of the KATAN Family Block Ciphers

Abstract

This paper investigates the security of the KTANTAN block cipher against differential fault analysis. This attack is considered to be first side channel analysis of KTANTAN in the literature. KTANTAN is a relative to the KATAN block cipher. Therefore, the previous fault analysis on KATAN family of block cipher is revisited. Similar to KATAN, KTANTAN has three variants namely KTANTAN32, KTANTAN48 and KTANTAN64. The inner structure of KTANTAN is similar to KATAN except the key schedule algorithms. KATAN has been practically broken by using fault analysis, employing a transient single-bit fault model, with the assumption is that the attacker is able to inject faults randomly into the internal state of the cipher. The attack is empowerd by extended cube method similarly as applied on KATAN. The complexity of this attack is 274 for KTANTAN32 and 276 for both KTANTAN48 and KTANTAN64. Furthermore, based on the obtained results, this paper concludes that KTANTAN is more robust against fault analysis compared to KATAN.