Biblio
In 2013, researchers from the National Security Agency of the USA (NSA) proposed two lightweight block ciphers SIMON and SPECK [3]. While SIMON is tuned for optimal performance in hardware, SPECK is tuned for optimal performance in software. At CHES 2015, Yang et al. [6] combined the "good" design components from both SIMON and SPECK and proposed a new lightweight block cipher SIMECK that is even more compact and efficient. In this paper we show that SIMECK is vulnerable to fault attacks and demonstrate two fault attacks on SIMECK. The first is a random bit-flip fault attack which recovers the n-bit last round key of Simeck using on average about n/2 faults and the second is a more practical, random byte fault attack which recovers the n-bit last round key of SIMECK using on average about n/6.5 faults.