BACKGROUND Standardised measures of behaviour have failed to detect short term improvement in children with autism following treatment with secretin. However, it is possible that standardised measures are insensitive to dimensions of child behaviour that are nonetheless detectable by parents. AIM To determine the ability of parents of children with autism to guess, under double blind conditio...

At Eurocrypt’98, Okamoto and Uchiyama presented a new trapdoor (one-way) function based on factoring [5], while Fujisaki and Okamoto, at CRYPTO’99, showed a generic conversion from just oneway encryption to chosen-ciphertext secure encryption in the random oracle model [3]. We point out here that the result of combining both schemes, called EPOC-2, has a better efficiency in security reduction,...

In this work, a simple semi-empirical model is proposed, based on Response Surface Model, RSM, to determine the shape of an attached oblique shock wave emanating from a pointed axisymmetric nose at zero angle of attack. Extensive supersonic visualization images have been compiled from various nose shapes at different Mach numbers, along with some others performed by the author for the present p...

This paper proposes a speed-up of a known-plaintext attack on some stream ciphers based on Linear Feedback Shift Registers (LFSRs). The algorithm consists of two basic steps: first, to guess the initial seed value of one of the LFSRs, and then to use the resulting binary sequence in order to deduce useful information about the cipher parameters. In particular, the proposed divide-and-conquer at...

In this work, we refine a partitioning technique recently proposed by Biham and Carmeli to improve the linear cryptanalysis of addition operations, and we propose an analogue improvement of differential cryptanalysis of addition operations. These two technique can reduce the data complexity of linear and differential attacks, at the cost of more processing time. Our technique can be seen of the...

This paper provides the Shannon theoretic coding theorems on the success probabilities of the impersonation attack and the substitution attack against secret-key authentication systems. Though there are many studies that develop lower bounds on the success probabilities, their tight upper bounds are rarely discussed. This paper characterizes the tight upper bounds in an extended secret-key auth...

A problem arising in taste testing, medical, and parapsychology experiments can be modeled as follows. A deck of n cards contains c i cards labeled i, 1 < i < r. A subject guesses at -the cards sequentially. After each guess the subject is told the card just guessed (or at least if the guess was correct or not). We determine the optimal and worst case strategies for subjects and the distributio...

Security is a important factor in computer system now a days. Users of computer system give a primary preference to security. Authentication is a process used to provide security to the user. Authentication is a process of identifying the person’s identity or conforming the identity of a particular person. There are various authentication method, but most commonly used method is textual passwor...