Collision attack

About: Collision attack is a research topic. Over the lifetime, 1093 publications have been published within this topic receiving 28389 citations.

Mitigation and Improving SHA-1 Standard Using Collision Detection Approach

Abstract: This paper introduces a collision detection methodology and an improved version of Secure Hash Algorithm (SHA-1) standard. The proposed work helps to protect weak primitives from any possible collision attack. Two designs are implemented to help protect and improve SHA-1 standard. The first design employs near collision detection approach that was proposed by Marc Stevens. The second design is the proposed work that employs two block calculation schemes. Both designs are tested and verified for examples of collided messages. The designs can detect the collision probability and produce a different hash for weak messages that are susceptible to collision attack.

Collision Attacks against the Knudsen-Preneel Compression Functions ∗

Abstract: Knudsen and Preneel (Asiacrypt’96 and Crypto’97) introduced a hash function design in which a linear error-correcting code is used to build a wide-pipe compression function from underlying blockciphers operating in Davies-Meyer mode. Their main design goal was to deliver compression functions with collision resistance up to, and even beyond, the block size of the underlying blockciphers. In this paper, we present new collision-finding attacks against these compression functions using the ideas of an unpublished work of Watanabe and the preimage attack of Ozen, Shrimpton, and Stam (FSE’10). In brief, our best attack has a time complexity strictly smaller than the block-size for all but two of the parameter sets. Consequently, the time complexity lower bound proven by Knudsen and Preneel is incorrect and the compression functions do not achieve the security level they were designed for.

A Dynamic Perfect Hash Function Defined by an Extended Hash Indicator Table

Abstract: This paper presents a new dynamic file organization scheme based on hashing. The hash functions used here, being defined by extended hash indicator tables (EHITs), are both dynamic and perfect. The allocated storage space can be enlarged and shrunk without reorganizing the data file. Simulation results show'that the storage utilization is approximately equal to 70% in an experiment where the number of rehash functions s=7, the size of a segment r=lO, and the size of the key set n varies from 1 to 1000. Since the hash functions are perfect, the retrieval operation needs only one disk access.

How to find many collisions of 3-pass HAVAL

Abstract: The hash function HAVAL is a well known Merkle-Damgard hash function such as MD4 and MD5. It has three variants, 3-, 4- and 5-pass HAVAL. On 3-pass HAVAL, the best known attack finds a collision pair with 27 computations of the compression function. To find k collision pairs, it requires 27k computations. In this paper, we present a better collision attack on 3-pass HAVAL, which can find k collision pairs with only 2k+33 computations. Further, our message differential is different from the previous ones. It is important to find collisions for different message differentials.

An improvement of chaos-based hash function in cryptanalysis approach: An experience with chaotic neural networks and semi-collision attack

Abstract: In this paper, the chaos-based hash function is analyzed, then an improved version of chaos-based hash function is presented and discussed using chaotic neural networks. It is based on the piecewise linear chaotic map that is used as a transfer function in the input and output of the neural network layer. The security of the improved hash function is also discussed and a novel type of collision resistant hash function called semi-collision attack is proposed, which is based on the collision percentage between the two hash values. In the proposed attack particle swarm optimization algorithm is used to define the fitness function parameters. Finally, numerical and simulation results provides strong collision resistance and high performance efficiency.