Collision attack

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

New observation on camellia

Abstract: In this paper, some observations on Camellia are presented, by which the Square attack and the Collision attack are improved. 11-round 256-bit Camellia without FL function is breakable with complexity of 2 250 encryptions. 9-round 128-bit Camellia without FL function is breakable with the complexity of 2 90 encryptions. And 10-round 256-bit Camellia with FL function is breakable with the complexity of 2 210 encryptions and 9-round 128-bit Camellia with FL function is breakable with the complexity of 2 122 encryptions. These results are better than any other known results. It concludes that the most efficient attack on Camellia is Square attack.

How To Find Weak Input Differences For MD5 Collision Attacks.

Abstract: Since the first feasible collision differential was given for MD5 in 2004 by Wang et al, a lot of work has been concentrated on how to improve it, but the researches on how to select weak input differences for MD5 collision attack are only sporadically scattered in literature. This paper focuses on a reasonable selection of weak input differences for MD5 collision attack, tries to answer some questions such as, what techniques can be use to satisfy bit conditions? which step in the second round can be the latest to apply a search on free bits without violating previously satisfied conditions? what is the optimal characterization of feasible collision differential propagation for MD5, by which we can find more weak input differences? is there any collision differentials better than Wang et al’s by some practical criteria? In this paper, a divide-and-conquer strategy is introduced with an optimal scheme of grouping the 64 steps of operation into five stages of independent condition fulfillment, and a feasible collision differential propagation is optimally characterized as a guide to select those 1-3-bit weak input differences, with their computational costs estimated. As a result, hundreds of thousands of weak input differences have been found, quite a number of which are superior to Wang et al’s. For example, a new differential collision attack with only 1-MSB input difference is developed with a time complexity of 2 MD5 compressions, two weak input differences are able to find a collision within 2 MD5 compressions. In particular, a 2-bit weak input difference is found to be able to construct a practical 1-block collision attack on MD5. This paper will provide a rich resource of colliding messages with different weak input differences, therefore much greatly increase the probability of finding a second MD5 pre-image for an arbitrarily given message.

An attack on hash function HAVAL-128

Abstract: In this paper, we give a fast attack against hash function—HAVAL-128. HAVAL was presented by Y. L. Zheng et al. at Auscrypto’92. It can be processed in 3, 4 or 5 passes, and produces 128, 160, 192, or 224-bit fingerprint. We break the HAVAL with 128-bit fingerprint. The conclusion is that, given any 1024-bit message m, we just make some modifications about m, and the modified message m can collide with another message m′ only with probability 1/27, where m′=m+Δm, in which Δm is a fixed difference selected in advance. In addition, two collision examples for HAVAL-128 are given in this paper.

Rotational Cryptanalysis of Round-Reduced Keccak

Abstract: In this paper we attack round-reduced Keccak hash function with a technique called rotational cryptanalysis. We focus on Keccak variants proposed as SHA-3 candidates in the NIST’s contest for a new standard of cryptographic hash function. Our main result is a preimage attack on 4-round Keccak and a 5-round distinguisher on Keccak-\(f\)[1600] permutation — the main building block of Keccak hash function.

A Collision-Resistant Rate-1 Double-Block-Length Hash Function

Abstract: This paper proposes a construction for collision resistant $2n$-bit hash functions, based on $n$-bit block ciphers with $2n$-bit keys. The construction is analysed in the ideal cipher model; for $n=128$ an adversary would need roughly $2^{122}$ units of time to find a collision. The construction employs ``combinatorial'' hashing as an underlying building block (like Universal Hashing for cryptographic message authentication by Wegman and Carter). The construction runs at rate~1, thus improving on a similar rate~1/2 approach by Hirose (FSE 2006).