Textbooks tell us that a birthday attack on a hash function h with range size r requires r trials (hash computations) to find a collision. But this is quite misleading, being true only if h is regular, meaning all points in the range have the same number of pre-images under h; if h is not regular, fewer trials may be required. But how much fewer? This paper addresses this question by introducin...

Intramolecular hydroxyl attack upon iron-coordinated nitriles in a {closo-2,1,10-FeC2B7} system forms imidates that allow construction of a tetra-cluster {FeC2B7}-{C2Co2}-{C2Co2}-{FeC2B7} molecule.

Recently multi-block collision attacks (MBCA) were found on the Merkle-Damg̊ard (MD)-structure based hash functions MD5, SHA-0 and SHA-1. In this paper, we introduce a new cryptographic construction called 3C devised by enhancing the MD construction. We show that the 3C construction is at least as secure as the MD construction against single-block and multi-block collision attacks. This is the f...

This paper deals with definitional aspects of the herding attack of Kelsey and Kohno, and investigates the provable security of several hash functions against herding attacks. Firstly, we define the notion of chosen-target-forced-midfix (CTFM) as a generalization of the classical herding (chosen-target-forced-prefix) attack to the cases where the challenge message is not only a prefix but may a...

Almost all current block-cipher-based MACs reduce their security to the pseudorandomness of their underlying block ciphers, except for a few of them to the unpredictability, a strictly weaker security notion than pseudorandomness. However, the latter MACs offer relatively low efficiency. In this paper, we investigate the feasibility of constructing rate-1 MACs from related-key unpredictable blo...

The hash function HAVAL is an Australian extension of well known Merkle-Damg̊ard hash functions such as MD4 and MD5. It has three variants, 3-, 4and 5-pass HAVAL. On 3-pass HAVAL, the best known attack finds a collision pair with 2 computations of the compression function. To find k collision pairs, it requires 2k computations. In this paper, we present a better collision attack on 3-pass HAVAL,...

Certificateless cryptography involves a Key Generation Center (KGC) which issues a partial key to a user and the user also independently generates an additional public/secret key pair in such a way that the KGC who knows only the partial key but not the additional secret key is not able to do any cryptographic operation on behalf of the user; and a third party who replaces the public/secret key...

The paper suggests an approach to network attack modeling and security evaluation which is realized in advanced Security Information and Event Management (SIEM) systems. It is based on modeling of computer network and malefactors’ behaviors, building attack graphs, processing current alerts for real-time adjusting of particular attack graphs, calculating different security metrics and providing...