Cryptanalysis of Full PRIDE Block Cipher.
Dai Yibin, Shaozhen Chen · 2014
Abstract. PRIDE is a lightweight block ciphers designed by Albrecht et al., appears in CRYPTO 2014. The designers claim that the construction of linear layers is nicely in line with a bit-sliced implementation of the Sbox layer and security. In this paper, we find 8 2-round iterative related-key differential characteristics, which can be used to construc-t 18-round related-key differentials. Then, by discussing the function g (1) r, we also find 4 2-round iterative related-key differential characteristics with ∆g (1) r (k1,2) = 0x80 and 4 2-round iterative characteristics with ∆g (1) r (k1,2) = 0x20 which cause three weak-key classes. Based on the related-key differentials, we launch related-key differential attack on full PRIDE. The data and time complexity are 239 chosen plaintexts and 260 encryptions, respectively. Moreover, by using multi related-key differentials, we improve the cryptanal-ysis, which requires 241.4 chosen plaintexts and 244 encryptions, respectively. Finally, by using 17-round related-key differentials, the cryptanalysis requires 234 plaintexts and 253.7 encryptions. These are the first results on full PRIDE.