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...]. Due to its much more complicated structure, especially of the message expansion, attacking it seems quite a difficult task. The progress of cryptanalysis of SHA-256 has been steady but rather slow =-=[5,27,13,14,7,18,17]-=-. The best publicly known collision attack [7,17] covers 24 steps out of the total 64. At the rump session of CRYPTO 2008 Sasaki announced a 36-step preimage attack [20], but the details have not been...

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...ollisions for Reduced SHA-256 271 as ‘relying on the same design principle as SHA-1 and MD5’, the best attack to date on SHA-256 is a collision attack for 24 out of 64 steps with practical complexity =-=[13,33]-=- and a preimage attack on 45 steps [18] having a complexity of 2255.5. Higher-order differentials have been introduced by Lai in [21] and first applied to block ciphers by Knudsen in [20]. The applica...

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...ttention. Apart from being marked as ‘relying on the same design principle as SHA-1 and MD5’, the best attack to date on SHA-256 is a collision attack for 24 out of 64 steps with practical complexity =-=[10,26]-=- and a preimage attack on 43 steps [1] having a complexity of 2 254.9 . In this work, we present an attack for the SHA-256 compression function reduced to 46 out of 64 steps with practical complexity....

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...f very intensive cryptanalysis in the world of hash functions. In contrast to its predecessors, collision attacks are no longer the major threat with the best attack on 24 rounds of the hash function =-=[12, 23]-=-. So far the best attacks on the SHA2 family are preimage attacks on the hash function in the splice-and-cut framework [1] and a boomerang distinguisher that is only applicable for the compression fun...

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...with respect to collision attacks. They found a differential characteristic resulting in a collision attack for 23 steps of SHA-256. Later this approach was extended to a collision attack on 24 steps =-=[4, 16]-=-. All these results use rather simple local collisions spanning over 9 steps, which are constructed mostly manually or using basic cryptanalytic tools. However, as pointed out in [4] it is unlikely th...

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...Following the attacks on SHA-0 [1] and SHA-1 [20], the attention of the cryptanalysis community has been directed to the SHA-2 family. Recent attacks against SHA-2 starting with [12], and followed by =-=[18, 16, 7,17]-=- have utilized certain previously unknown properties in the round function of SHA-2. These have led to upto 24-step attacks against both SHA-256 and SHA-512. A unified combinatorial description of the...

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...attack on SHA-2 reduced to 19 steps. Afterthat, several researches have improved the result. To the best of our knowledge, the best collision attacks so far are the one proposed by Indesteege et al. =-=[3]-=- and the one proposed by Sanadhya and Sarkar [10], which present collision attacks on 24 steps. Apart from the collision attack, the only analysis we know is the one proposed by Isobe and Shibutani [4...

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... functions SHA (Standard Hash Algorithm) [FIPS 2008], was standardized by the NIST (National Institute of Standards and Technology) and currently is used in many applications and protocols. Recently, several attacks on hash algorithms of SHA family were found. In 2005, [Biham et al. 2005] and [Rijmen and Oswald 2005] showed collision attacks of reduced versions of SHA-1. In the same year, [Wang et al. 2005] showed an attack that theoretically breaks the resistance to collision. The second version of SHA, SHA-2, is based on SHA-1 and already had attacks in its reduced versions, as is shown in [Indesteege et al. 2009]. In 2007, NIST started a new competition to select the new version of SHA algorithm, called SHA-3 [NIST 2007]. After two rounds of competition, five finalists were chosen: BLAKE, Grøstl , JH, Keccak and Skein. In 2012, Keccak [Bertoni et al. 2008] was announced as the winner. This work shows how to take advantage of the new vector instructions (AVX/AVX2) introduced on Intel R© Architecture Processors to implement the SHA-3 family. We developed a sequential and a parallel versions of the SHA-3 hash function for the four security levels 112, 128, 192 and 256 bits; in addition, the extendable-o...