In this article, the RIPEMD-160 hash function is studied in detail. To analyze the hash function, we have extended existing approaches and used recent results in cryptanalysis. While RIPEMD and RIPEMD-128 reduced to 3 rounds are vulnerable to the attack, it is not feasible for RIPEMD-160. Furthermore, we present an analytical attack on a round-reduced variant of the RIPEMD-160 hash function. To...

Bandwidth demands of communication networks are rising permanently. Thus, the requirements to modern routers regarding packet classification are rising accordingly. Conventional algorithms for packet classification use either a huge amount of memory or have high computational demands to perform the task. Using a hash function in order to classify packets is promising regarding both memory and c...

A new way of constructing (minimal) perfect hash functions is described. The technique considerably reduces the overhead associated with resolving buckets in two-level hashing schemes. Evaluating a hash function requires just one multiplication and a few additions apart from primitive bit operations. The number of accesses to memory is two, one of which is to a fixed location. This improves the...

Although hashing techniques are widely used for indexing moving objects, they cannot handle the dynamic workload, e.g. the traffic at peak hour vs. that in the night. This paper proposes an adaptive hashing technique to support the dynamic workload efficiently. The proposed technique maintains two levels of the hashes, one for fast moving objects and the other for quasi-static objects. A moving...

We consider the problem of covering the complete r-uniform hypergraphs on n vertices using complete r-partite graphs. We obtain lower bounds on the size of such a covering. For small values of r our result implies a lower bound of Ω( e r r √ r n log n) on the size of any such covering. This improves the previous bound of Ω(rn log n) due to Snir [5]. We also obtain good lower bounds on the size ...

Investigating how to construct a secure hash algorithm needs in-depth study, as various existing hash functions like the MD5 algorithm have recently exposed their security flaws. At the same time, hash function based on chaotic theory has become an emerging research in the field of nonlinear information security. As an extension of our previous research works, a new chaotic iterations keyed has...

The concept of truly independent hash functions is extremely useful in the design of randomized algorithms. We have a large universe U of keys, e.g., 64-bit numbers, that we wish to map randomly to a range [m] = {0, ...,m− 1} of hash values. A truly random hash function h : U → [m] assigns an independent uniformly random variable h(x) to each key in x. The function h is thus a |U |-dimensional ...

Super-simple designs are useful in constructing codes and designs such as superimposed codes and perfect hash families. Recently, Gronau et al determined the existence of super-simple (v, 5, 2)-BIBDs with possible exceptions of v ∈ {75, 95, 115, 135, 195, 215, 231, 285, 365, 385, 515}. In this article, we investigate the existence of a super-simple (v, 5, 4)-BIBD and show that such a design exi...

A robust hash function allows different parties to extract a consistent key from a common fuzzy source (e.g., an image gone through noisy channels), which can then be used to establish a cryptographic session key among the parties without the need for interactions. These functions are useful in various communication scenarios, where the security notions are different. We study these different s...