Group: Hash Functions - library 6 articles

Abstract

The security challenges posed by RFID-tag deployments are well-known. In response there is a rich literature on new cryptographic protocols and an on-tag hash function is often assumed by protocol designers. Yet cheap tags pose severe implementation challenges and it is far from clear that a suitable hash function even exists. In this paper we consider the options available, including constructions based around compact block ciphers. While we describe the most compact hash functions available today, our work serves to highlight ...

Abstract

This paper describes a new compression function, MAME designed for hardware-oriented hash functions which can be used in applications with reduced hardware requirements. MAME takes a 256-bit message block and a 256-bit chaining variable as input and produces a 256-bit output. In the light of recent attacks on MD5 and SHA-1, our design strategy is very conservative, and we show that our compression function is secure against various kinds of widely known attacks with very large security margins. The simple logical ...

Abstract

Lane is a cryptographic hash function that has been entered as a candidate in the NIST SHA-3 competition by the COSIC research group of the Katholieke Universiteit Leuven, Belgium. The aims of Lane are to be secure, easy to understand, elegant and flexible in implementation. It reuses components from the AES block cipher. Lane can take advantage of the parallelism offered by modern high-performance CPUs, but also scales down to embedded systems. Another advantages of Lane is the fact that its ...

Abstract

Many of the popular Merkle-Damgård hash functions have turned out to be not collision-resistant (CR). The problem is that we no longer know if these hash functions are even second-preimage-resistant (SPR) or one-way (OW), without the underlying compression functions being CR. We remedy this situation by introducing the “split padding” into a current Merkle-Damgård hash function H. The patched hash function resolves the problem in the following ways: (i)  is SPR if the underlying compression function h satisfies an “SPR-like” property, and (ii)  is ...

Abstract

The Random Oracle Model and the Ideal Cipher Model are two well known idealised models of computation for proving the security of cryptosystems. At Crypto 2005, Coron et al. showed that security in the random oracle model implies security in the ideal cipher model; namely they showed that a random oracle can be replaced by a block cipher-based construction, and the resulting scheme remains secure in the ideal cipher model. The other direction was left as an open problem, i.e. constructing ...

Abstract

We describe a new function called SQUASH (which is short for SQUare-hASH), which is ideally suited to challenge-response MAC applications in highly constrained devices such as RFID tags. It is exceptionally simple, requires no source of random bits, and can be efficiently implemented on processors with arbitrary word sizes. Unlike other ad-hoc proposals which have no security analysis, SQUASH is provably at least as secure as Rabin’s public key encryption scheme in this application. ...