Threshold signature scheme based on factoring and discrete logarithms problems

Digital signature scheme is a mathematical scheme for demonstrating the authenticity of a digital message or document.The ordinary digital signature scheme allows single user to sign an online transaction.For the reason of integrity, nowadays many documents and online transactions need to be signed by more than one person in an organization. Threshold digital signature scheme are developed to overcome this problem.In a threshold signature scheme, out of members are required to sign an online transaction.In this research, we developed a new threshold signature scheme based on two number theory problems, namely factoring and discrete logarithms.The advantage of our scheme is based on the fact that it is very hard to solve both problems simultaneously.The security analysis of our scheme shows that our scheme is invulnerable against several securities threat, while performance evaluation shows that our scheme requires reasonable number of operations in signing and verifying

A threshold authenticated encryption scheme using hybrid problems

In this paper, we propose a threshold authenticated encryption scheme using both factoring and discrete logarithm problems.We apply the concept of threshold cryptography in the verification and message recovery phase, where t out of n recipients are required to verify and recover the message. Security analysis shows that our scheme will remain secure even if one of these problems can be solved

A variational discrete filled function approach in discrete global optimization

Many real-life applications governed by discrete variables poss multiple local optimal solutions, which requires the utilization of global optimization tools find the best solution amongst them.The main difficulty in determining the best solution, or also known as the global solution, is to escape from the basins surrounding local minimums.To overcome this issue, an auxiliary function is introduced in discrete filled function method which turns the local minimizer of the original function become a maximizer.Then, an improved local minimum is found by minimizing the filled function, otherwise the edge of the feasible region is attained.Based on a discrete filled function method from the literature, we propose a modification particularly on the neighbourhood search to enhance its computational efficiency.Numerical results suggest that the proposed algorithm is efficient in solving large scale complex discrete optimization problems

A revised methodology for estimating the relative size of the annual recreational catch of bass in England and Wales over the period 1986-88

Previously issued as CEMARE research paper (Old Series) no. 69SIGLEAvailable from British Library Document Supply Centre- DSC:7755.0108(PU-CEMARE-RP--34) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Scattered data interpolation using combination method of triangular patches

This monograph is a comprehensive report on scattered data interpolation using combination method of triangular patches where the interpolating surface comprise the combination of quintic Hermite and interior interpolation operators.It is based on the findings of a university grant research project sponsored by Universiti Utara Malaysia. In particular, the contents of this monograph are useful for students and researchers especially in the area of Computer Aided Geometric Design (CAGD) and generally the contents will also benefit academicians as well as practitioners who have interest in the application of the triangulation based interpolation method in real world problems