Accelerating the Best Trail Search on AES-Like Ciphers

New Insights on AES-Like SPN Ciphers

It has been proved in Eurocrypt 2016 by Sun et al. that if the details of the S-boxes are not exploited, an impossible differential and a zero-correlation linear hull can extend over at most 4 rounds of the AES. This paper concentrates on distinguishing properties of AES-like SPN ciphers by investigating the details of both the underlying S-boxes and the MDS matrices, and illustrates some new i...

Differential Trail Weights in AES-like Ciphers Using New Permutation Layers

Differential cryptanalysis is about finding trails which involve a low amount of active S-box operations. Such patterns simplify the difference propagation and thus the computations of the secret round keys. The weight of a trail expresses the total number of non-zero Sbox input differences within the cipher for a certain execution and is highly dependent on the specified permutation layers. Th...

On algebraic and statistical properties of AES-like ciphers

Looting the LUTs : FPGA Optimization of AES and AES-like Ciphers for Authenticated Encryption

In this paper, we investigate the efficiency of FPGA implementations of AES and AES-like ciphers, specially in the context of authenticated encryption. We consider the encryption/decryption and the authentication/verification structures of OCB-like modes (like OTR or SCT modes). Their main advantage is that they are fully parallelisable. While this feature has already been used to increase the ...

Analyzing Permutations for AES-like Ciphers: Understanding ShiftRows

Designing block ciphers and hash functions in a manner that resemble the AES in many aspects has been very popular since Rijndael was adopted as the Advanced Encryption Standard. However, in sharp contrast to the MixColumns operation, the security implications of the way the state is permuted by the operation resembling ShiftRows has never been studied in depth. Here, we provide the first struc...