In this paper, the impossible differential cryptanalysis is extended to MAC algorithms Pelican, MT-MAC and PC-MAC based on AES and 4-round AES. First, we collect message pairs that produce the inner near-collision with some specific differences by the birthday attack. Then the impossible differential attack on 4-round AES is implemented using a 3-round impossible differential property. For Peli...

In this paper we apply impossible differential attacks to reduced round AES. Using various techniques, including the early abort approach and key schedule considerations, we significantly improve previously known attacks due to Bahrak-Aref and Phan. The improvement of these attacks leads to the best known impossible differential attacks on 7-round AES-128 and AES-192, as well as to the best kno...

As an international standard adopted by ISO/IEC, the block cipher Camellia has been used in various cryptographic applications. In this paper, we reevaluate the security of Camellia against impossible differential cryptanalysis. Specifically, we propose several 7-round impossible differentials with the FL/FL layers. Based on them, we mount impossible differential attacks on 11-round Camellia192...

Impossible differential cryptanalysis is an important tool for evaluating the security level of a block cipher, and the key step of this cryptanalysis is to find the longest impossible differential. This paper focuses on retrieving impossible differentials for m-cell Skipjack-like structure with SP/SPS round function (named SkipjackSP and SkipjackSPS resp.). Up to now, known longest impossible ...

Some new near 5 rounds impossible differential properties of AES are first presented in this paper, in which active bytes of 1 round or 5 round are in different columns and in favor of extension. Additionally, we first propose the complexities expressions of an universal impossible differential attack, which can help us to rapidly search appropriate impossible differential paths. More important...

Many attacks on iterated block ciphers rely on statistical considerations using plaintext/ciphertext pairs to distinguish some part of the cipher from a random permutation. We provide here a simple formula for estimating the amount of plaintext/ciphertext pairs which is needed for such distinguishers and which applies to a lot of different scenarios (linear cryptanalysis, differentiallinear cry...

In this paper, we present several new related-key impossible differential attacks on 7and 8-round AES-192, following the work of Eli Biham and Orr Dunkelman et al. [1]. We choose another relation of the two related keys, start attacks from the very beginning(instead of the third round in [1]) so as to improve the data and time complexities of their attacks. Furthermore, we point out and correct...

MISTY1 is a Feistel block cipher that received a great deal of cryptographic attention. Its recursive structure, as well as the added FL layers, have been successful in thwarting various cryptanalytic techniques. The best known attacks on reduced variants of the cipher are on either a 4-round variant with the FL functions, or a 6-round variant without the FL functions (out of the 8 rounds of th...

In this paper we examine the strength of AES-256 against the related-key impossible differential attack, following the work in [1] and [2]. Firstly, we present a carefully chosen relation between the related keys, which can be extended to 8-round(even more rounds) subkey differences. Then, we construct a 5.5-round related-key impossible differential. Using the differential, we present an attack...