SHipher: Families of Block Ciphers based on SubSet-Sum Problem.
Xiali Hei, Binheng Song · 2014
In this paper, we describe the families of block ciphers named SHipher. We show a symmetric encryption framework based on the SubSet-Sum problem. This framework can provide families of secure, flexible, and any-size block ci-phers. We have extensively cryptanalyzed our encryption framework. We can easily control the computational cost by a key selection. Also, this framework offers excellent performance and it is flexible and general enough to admit a variety of implementations on different non-Abelian groups. In this paper, we provide one implementation using a group of matrices whose determinants are 1. This implementation accepts any block size satisfying 3l − 1. If l = 21, the block size is 62 bits, which suits for full spectrum of lightweight applications. While if l = 341, the block size is 1022, which provides high security level up to resistant 2684 differential-attack effort and 21022 brute-force attack effort.