A global competition is currently taking place to select a hash function which will become a new standard in the field of cryptography. The competition was announced in 2007 by the National Institute of Standards and Technology (NIST) to find a successor to its previous Secure Hash Algorithm (SHA) standards, SHA-1 and SHA-2. The submissions have been narrowed down to a set of five, judged by th...

So far, the complex characteristics needed for the recent collision attacks on members of the SHA family have been constructed manually by Wang et al. In this report, we describe a method to search for them automatically. It succeeds for many message differences and also for multi-block attacks. This answers open questions posed by many researchers in the field. As a proof of concept, we give a...

In 2007, the U.S. National Institute of Standards and Technology (NIST) announced a public contest aiming at the selection of a new standard for a cryptographic hash function. In this paper, the security margin of five SHA-3 finalists is evaluated with an assumption that attacks launched on finalists should be practically verified. A method of attacks is called logical cryptanalysis where the o...

In this work, we introduce a new non-random property for hash/compression functions using the theory of higher order differentials. Based on this, we show a second-order differential collision for the compression function of SHA-256 reduced to 47 out of 64 steps with practical complexity. We have implemented the attack and provide an example. Our results suggest that the security margin of SHA-...

In 1992, NIST announced a proposed standard for a collision-free hash function. The algorithm for producing the hash value is known as the Secure Hash Algorithm (SHA), and the standard using the algorithm in known as the Secure Hash Standard (SHS). Later, an announcement was made that a scientist at NSA had discovered a weakness in the original algorithm. A revision to this standard was then an...

At Crypto 2007, Joux and Peyrin showed that the boomerang attack, a classical tool in block cipher cryptanalysis, can also be very useful when analyzing hash functions. They applied their new theoretical results to SHA-1 and provided new improvements for the cryptanalysis of this algorithm. In this paper, we concentrate on the case of SHA-0. First, we show that the previous perturbation vectors...

Most of recent collision attacks on SHA-0 are based on the differential path given by Xiaoyun Wang et al. Their disturbance vector was thought to be the best one. We noticed that the way they calculate number of sufficient conditions is not accurate, and we also found some new properties of the third Boolean function MAJ (b ∧ c) ∨ (c ∧ d) ∨ (d ∧ b). In this paper we present a new disturbance ve...

This paper analyses the cryptographic hash function SHA1 in encryption mode. A detailed analysis is given of the resistance of SHA-1 against the most powerful known attacks today. It is concluded that none of these attacks can be applied successfully in practice to SHA-1. Breaking SHA-1 in encryption mode requires either an unrealistic amount of computation time and known/chosen texts, or a maj...

A Streptococcus sanguis 133-79 adhesin identified by the monoclonal antibody 1.1 (MAb 1.1) binds both saliva-coated hydroxylapatite (sHA) and platelets. The complementary binding site(s) for the adhesin was identified by the anti-idiotypical MAb 2.1. To learn if this adhesion system, marked by the antiadhesin MAb 1.1 and anti-binding site MAb 2.1, is commonly used by strains within the sanguis ...

This paper describes our Skein-512 hardware implementation. Skein is a semi-finalist in the NIST hash competition to create SHA-3, with Skein-512 being the primary submission. We compare our implementation of Skein-512 with other published hardware implementations of Skein, and with similar implementations for SHA-1 and SHA-2. We discuss four variations of our critical path to explore the throu...