Hash functions are inseparable part of modern computer world. Fast associative arrays so popular among computer programmers for their robustness and simplicity, are based on them. Their performance greatly depends on their design and although their roots are deep in the past, the topic of designing a well performing hash function is still often discussed today. There is currently a plenty of ex...

In recent years there have been a series of serious and alarming cryptanalytic attacks on several commonly-used hash functions, such as MD4, MD5, SHA-0, and SHA1 [13, 38]. These culminated with the celebrated work of Wang, Yin, and Yu from 2005, which demonstrated relatively efficient methods for finding collisions in the SHA-1 hash function [37]. Although there are several cryptographic hash f...

This paper describes a new software-efficient 256-bit hash function, FORK-256. Recently proposed attacks on MD5 and SHA-1 motivate a new hash function design. It is designed not only to have higher security but also to be faster than SHA-256. The performance of the new hash function is at least 30% better than that of SHA-256 in software. And it is secure against any known cryptographic attacks...

In a recent paper, Lucks espoused a “failure-friendly” approach to hash function design [12]. We expand on this idea in two main ways. First of all, we consider the notion of a weak ideal compression function, which is vulnerable to strong forms of attack, but is otherwise random. We show that such weak ideal compression functions can be used to create secure hash functions, thereby giving a de...

In this paper, the author studies the fast cryptographic hash function. This work suggests a different notion with respect to the traditional hash functions, MD5, SHA-1, and Whirlpool. The notion of block cipher based hash function is abandoned. According to the flexibility of attack, it shows how this hash function is no longer vulnerable to the known collision attacks. Finally, the author pro...

In a recent paper in crypto-04, A. Joux [6] showed a multicollision attacks on the classical iterated hash function. He also showed how the multicollision attack can be used to get a collision attack on the concatenated hash function. In this paper we have shown that the multicollision attacks exist in a general class of sequential or tree based hash functions even if message blocks are used tw...

In this article, we present an improved collision attack on the hash function proposed by Shin et al. at PKC’98. The attack has a complexity of about 2 hash computations, while the previous attack of Chang et al. presented at SAC 2002 has a complexity of about 2 hash computations. In the analysis of the hash function we combined existing approaches with recent results in cryptanalysis of hash f...

RC4-Hash is a variable digest length cryptographic hash function based on the design of the RC4 stream cipher. In this paper, we show that RC4-Hash is not collision resistant. Collisions for any digest length can be found with an expected effort of less than 2 compression function evaluations. This is extended to multicollisions for RC4-Hash. Finding a set of 2 colliding messages has an expecte...

1 This paper presents a new hash function design, which is different from the popular designs of the MD4-family. Seen in the light of recent attacks on MD4, MD5, SHA-0, SHA-1, and on RIPEMD, there is a need to consider other hash function design strategies. The paper presents also a concrete hash function design named SMASH. One version has a hash code of 256 bits and appears to be at least as ...