SMS4 is a 128-bit block cipher used in WAPI (the Chinese national standard for wireless networks). Up until recently, the best attacks on SMS4 known, in terms of the number of rounds, were the rectangle attack on 14 rounds and the impossible differential attack on 16 rounds (out of 32 rounds) presented by Lu. While analyzing them, we noticed that these attacks have flaws and that their complexi...

Tracking bits through block ciphers and optimizing attacks at hand is one of the tedious task symmetric cryptanalysts have to deal with. It would be nice if a program will automatically handle them at least for well-known attack techniques, so that cryptanalysts will only focus on nding new attacks. However, current automatic tools cannot be used as is, either because they are tailored for spec...

This paper develops several new techniques of cryptanalyzing MACs based on block ciphers, and is divided into two parts. The first part presents new distinguishers of the MAC construction Alred and its specific instance Alpha-MAC based on AES. For the Alred construction, we first describe a general distinguishing attack which leads to a forgery attack directly with the complexity of the birthda...

While recent publications have shown strong relations between impossible differential and zero-correlation distinguishers as well as between zero-correlation and integral distinguishers, we analyze in this paper some relations between the underlying key-recovery attacks against Type-II Feistel networks. The results of this paper are build on the relation presented at ACNS 2013. In particular, u...

ICEPOLE is a CAESAR candidate with the intermediate level of robustness under nonce misuse circumstances in the original document. In particular, it was claimed that key recovery attack against ICEPOLE is impossible in the case of nonce misuse. ICEPOLE is strong against the differential cryptanalysis and linear cryptanalysis. In this paper, we developed the differential-linear attacks against I...

block ciphers have wide applications for hardware and software implementations. in this paper, a new block cipher algorithm with provable security is proposed. the whole structure of the algorithm is novel and has a good encryption and decryption performance. additionally, it has good security with few number of rounds. the structure of the proposed algorithm consists of 4-rounds feistel-like w...

This thesis focuses on cryptanalysis techniques and design of block ciphers. In particular, modern analysis methods such as square, boomerang, impossible differential and linear attacks are described and applied to real block ciphers. The first part of this thesis concentrates on the two most relevant modern cryptanalysis techniques: linear and differential cryptanalysis. These and related tech...

We describe two new techniques of side-channel cryptanalysis which we call the impossible collision attack and the multiset collision attack. These are inspired by the state-of-the-art cryptanalytic techniques of impossible differential attacks [BBS99] and partial-function collision attacks [GM00] respectively. Using these techniques on an example of the AES we show that one has to mask all the...

The block ciphers MISTY1 and MISTY2 proposed by Matsui are based on the principle of provable security against differential and linear cryptanalysis. This paper presents attacks on reduced-round variants of both ciphers, without as well as with the key-dependent linear functions FL. The attacks employ collision-searching techniques and impossible differentials. KASUMI, a MISTY variant to be use...