This paper presents the Generalized Randomized Iterate of a (regular) one-way function f and show that it can be used to build Universal One-Way Hash Function (UOWHF) families with O(n) key length. We then show that Shoup’s technique for UOWHF domain extension can be used to improve the efficiency of the previous construction. We present the Reusable Generalized Randomized Iterate which consist...

This paper reveals a duality between constructions of two basic cryptographic primitives pseudo random string generators and one way hash functions Applying the duality we present a construction for universal one way hash functions assuming the existence of one way permutations Under a stronger assumption the existence of distinction intractable permutations we prove that the construction const...

We answer the question of Reyhanitabar et al. from FSE’09 of constructing a domain extension scheme for enhanced target collisionresistant (eTCR) hash functions with sublinear key expansion. The eTCR property, introduced by Halevi and Krawczyk [1], is a natural fit for hashand-sign signature schemes, offering an attractive alternative to collisionresistant hash functions. We prove a new composi...

Many of the popular Merkle-Damg̊ard 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-Damg̊ard hash function H. The patched h...

MD2 is an early hash function developed by Ron Rivest for RSA Security, that produces message digests of 128 bits. In this paper, we show that MD2 does not reach the ideal security level of 2. We describe preimage attacks against the underlying compression function, the best of which has complexity of 2. As a result, the full MD2 hash can be attacked in preimage with complexity of 2.

In the era of Internet Things (IoT), security is a very important issue. Recently, some studies have been proposed based on applications Cellular Automata (CA). These works simplicity and high speed computation CA, are suitable for resource-constrained IoT. this paper, we make use CA propose sliding-window (SWCA)-based one-way hash function. The captures input data randomly operation promotes c...

Naor and Yung ((NY89]) show that a one-bit-compressing universal one-way hash function (UOWHF) can be constructed based on a one-way permutation. This construction can be iterated to build a UOWHF which compresses by "n bits, at the cost of "n invocations of the one-way permutation. We show that this construction is not far from optimal, in the following sense: there exists an oracle relative t...

We present a new framework for proving fully black-box separations and lower bounds. We prove a general theorem that facilitates the proofs of fully black-box lower bounds from a one-way function (OWF). Loosely speaking, our theorem says that in order to prove that a fully black-box construction does not securely construct a cryptographic primitive Q (e.g., a pseudo-random generator or a univer...

An one-way hash chain generated by the iterative use of a one-way hash function on a secret value has recently been widely employed to develop many practical cryptographic solutions, especially electronic micropayment schemes. In this paper, we propose a new concept called a weighted one-way hash chain. We then proceed to use the new concept to improve in a significant way the performance of mi...