Improved Linear Cryptanalysis of Reduced-Round SIMON-32 and SIMON-48 [chapter]

Mohamed Ahmed Abdelraheem, Javad Alizadeh, Hoda A. Alkhzaimi, Mohammad Reza Aref, Nasour Bagheri, Praveen Gauravaram
2015 Lecture Notes in Computer Science  
In this paper we analyse two variants of SIMON family of light-weight block ciphers against linear cryptanalysis and present the best linear cryptanalytic results on these variants of reduced-round SIMON to date. We propose a time-memory trade-off method that finds differential/linear trails for any permutation allowing low Hamming weight differential/linear trails. Our method combines low Hamming weight trails found by the correlation matrix representing the target permutation with heavy
more » ... g weight trails found using a Mixed Integer Programming model representing the target differential/linear trail. Our method enables us to find a 17-round linear approximation for SIMON-48 which is the best current linear approximation for SIMON-48. Using only the correlation matrix method, we are able to find a 14-round linear approximation for SIMON-32 which is also the current best linear approximation for SIMON-32. The presented linear approximations allow us to mount a 23-round key recovery attack on SIMON-32 and a 24-round Key recovery attack on SIMON-48/96 which are the current best results on SIMON-32 and SIMON-48. In addition we have an attack on 24 rounds of SIMON-32 with marginal complexity.
doi:10.1007/978-3-319-26617-6_9 fatcat:wnwcuux7ajb3rnv5xejmhgt4zq