A one-way hashing algorithm is a deterministic algorithm that compresses an arbitrary long message into a value of specified length. The output value represents the fingerprint or digest of the message. A cryptographically useful property of a one-way hashing algorithm is that it is infeasible to find two distinct messages that have the same fingerprint. This paper proposes a one-way hashing algorithm called HAVAL. HAVAL compresses a message of arbitrary length into a fingerprint of 128, 160, 192, 224 or 256 bits. In addition, HAVAL has a parameter that controls the number of passes a message block (of 1024 bits) is processed. A message block can be processed in 3, 4 or 5 passes. By combining output length with pass, we can provide fifteen (15) choices for practical applications where different levels of security are required. The algorithm is very efficient and particularly suited for 32-bit computers which predominate the current workstation market. Experiments show that HAVAL is 60%...

In this paper we study two possible approaches to improving existing schemes for constructing hash functions that hash arbitrary long messages. First, we introduce a continuum of function classes that lie between universal one-way hash functions and collision-resistant functions. For some of these classes efficient (yielding short keys) composite schemes exist. Second, we prove that the schedule of the Shoup construction, which is the most efficient composition scheme for universal one-way hash functions known so far, is optimal.

This paper determines an exact relationship between collision-free hash functions and other cryptographic primitives. Namely, it introduces a new concept, the pseudopermutation, and shows that the existence of collision-free hash functions is equivalent to the existence of claw-free pairs of pseudo-permutations. We also give a simple construction of collision-free hash functions from everywhere-defined claw-free (pseudo-) permutations. 1 Introduction Hash functions with various cryptographic properties have been studied extensively, especially with respect to signing algorithms (see [2, 3, 4, 10, 12, 14, 15]). We focus on the most natural of these functions, the collision-free hash functions. A function h is a collision-free hash function if jh(x)j jxj \Gamma 1 and it is infeasible, given h and 1 k , to find a pair (x; y) so that jxj = jyj = k and h(x) = h(y). These functions were first carefully studied by Damgard [2] and have found several applications. In particular, they have b...

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 constitutes a collision-intractable hash function. Using ideas behind the construction, we propose practical one-way hash functions, the fastest of which compress nearly 2n-bit long input into n-bit long output strings by applying only twice a one-way function. 1

We discuss the security of Message Authentication Code (MAC) schemes from the viewpoint of differential attack, and propose an attack that is effective against DES-MAC and FEAL-MAC. The attack derives the secret authentication key in the chosen plaintext scenario. For example, DES(8-round)-MAC can be broken with 2 34 pairs of plain text, while FEAL8-MAC can be broken with 2 22 pairs. The proposed attack is applicable to any MAC scheme, even if the 32-bits are randomly selected from among the 64-bits of ciphertext generated by a cryptosystem vulnerable to differential attack in the chosen plaintext scenario.

Abstract. One-way hash functions are an important toolinachieving authentication and data integrity. The aim of this paper is to propose anovel one-way hash function based on cellular automata whose cryptographic properties have been extensivelystudiedover the past decade or so. Furthermore, security of the proposed one-way hash function is analyzed by the use of very recently published results on applications of cellular automata in cryptography. The analysis indicates that the one-way hash function is secure against all known attacks. An important feature of the proposed one-way hash function is that it is especially suitable for compact and fast implementation in hardware, which is particularly attractive to emerging security applications that employ smart cards, such asdigital identi cation cards and electronic cash payment protocols, 1

This paper proposes a novel one-way hash function that can serve as a tool in achieving authenticity and data integrity. The one-way hash function can be viewed as a representative of a family of fast dedicated one-way hash functions whose construction is based on linear cellular automata over GF(q). The design and analysis of security of the function is accomplished by the use of very recently published results on cellular automata and their applications in cryptography. The analysis indicates that the one-way hash function is secure against all known attacks. A promising property of the proposed one-way hash function is that it is especially suitable for compact and fast implementation.

operated in hostile unattended environment so authentication is one of the important security requirements. Because of the resource constrained characteristics of WSN, the authentication scheme should sustain a lesser amount of computational as well as communication overhead. Some schemes proposed in literature are vulnerable to node compromised attack. Some schemes do not provide session-key agreement. In this paper, we concentrate on improvement of authentication schemes to withstand against the node compromise attack. Additionally, our scheme also provides mutual authentication, session key agreement and protection against replay attack.