Recently G. Jakimoski and L. Kocarev cryptanalzed two chaotic cryptosystems without using chaotic synchronization – Baptista cryptosystem and Alvarez cryptosystem. As a result, they pointed out that neither of the two cryptosystems are secure to known-plaintext attacks. In this letter, we re-study the performance of Jakimoski-Kocarev attack on Baptista cryptosystem and find that it is not effic...

Recently, a VoIP (voice over Internet protocol) technique with a new hierarchical data security protection (HDSP) scheme was proposed by using a secret chaotic bit sequence. This paper points out some insecure properties of the HDSP scheme, and then uses them to develop known/chosen-plaintext attacks. The following main findings are: 1) given n known plaintexts, about (100− 50 2n ) percent of s...

The well known binary and decimal representations of the integers, and other similar number systems, admit many generalisations. Here, we investigate whether still every integer could have a finite expansion on a given integer base b, when we choose a digit set that does not contain 0. We prove that such digit sets exist and we provide infinitely many examples for every base b with |b| ≥ 4, and...

We propose a cryptanalysis of the original Domingo-Ferrer’s algebraic privacy homomorphism. We show that the scheme over Zn can be broken by d + 1 known plaintexts in O(d3 log n) time when it has d times expansion through the encryption. Furthermore even when the public modulus n is kept secret, it can be broken by d + 2 known plaintexts in time at most O(d5 log(dn)).

Optimistic fair exchange (OFE) is a protocol for solving the problem of exchanging items or services in a fair manner between two parties, a signer and a verifier, with the help of an arbitrator which is called in only when a dispute happens between the two parties. In almost all the previous work on OFE, after obtaining a partial signature from the signer, the verifier can present it to others...

The choice of an operator in evolutionary computation is generally based on comparative runs of the algorithms. However, some statistical a priori measures, based on samples of (parents-oospring), have been proposed to avoid such brute comparisons. This paper surveys some of these works in the context of binary crossover operators. We rst extend these measures to overcome some of their limitati...

This paper proposes new factorizations for computing the Neumann series. The factorizations are based on fast algorithms for small prime sizes series and the splitting of large sizes into several smaller ones. We propose a different basis for factorizations other than the well-known binary and ternary basis. We show that is possible to reduce the overall complexity for the usual binary decompos...

T HIS provocative remark has been attributed to the famous industrial statistician, Cuthbert Daniel, by Box et al. (2005) in their well-known text on the design of experiments. Split-Plot experiments were invented by Fisher (1925) and their importance in industrial experimentation has been long recognized (Yates (1936)). It is also well known that many industrial experiments are fielded as spli...

We explore scalability issues of the text classification problem where using (multi)labeled training documents we try to build classifiers that assign documents into classes permitting classification in multiple classes. A new class of classification problems, called ‘scalable’ is introduced that models many problems from the area of Web mining. The property of scalability is defined as the abi...

We present a coalescent process where three particles merge at each coagulation step. Using a random walk representation, we prove duality with a fragmentation process, whose fragmentation law we specify explicitly. Furthermore, we give a second construction of the coalescent in terms of random binary forests and study asymptotic properties. Starting from N particles of unit mass, we obtain und...