In 2008, based on the two-party Diffie–Hellman technique, Biswas proposed a contributory group key exchange protocol called the Group-DH protocol. This contributory property is an important one of group key agreement. Unfortunately, in this paper we show that the proposed Group-DH protocol is not a contributory group key exchange protocol. Therefore, we propose an improved group key exchange pr...

Recent research has shown that the single-user security of optimistic fair exchange cannot guarantee the multi-user security. This paper investigates the conditions under which the security of optimistic fair exchange in the single-user setting is preserved in the multi-user setting. We first introduce and define a property called “Strong ResolutionAmbiguity”. Then we prove that in the certifie...

Customer valuations are not just about service quality but also process efficiency. As a result organisations need to continuously reassess their business processes in order to improve their operations and service delivery to their customers. Conveyancing deals with the exchange of immovable property. Although conveyancing processes are wider in context than conventional organisational-level bu...

Nitrate is an anion of major importance particularly in biological areas. Excessive amounts in water supplies indicate pollution from sewage or agricultural effluents. The effects of excessive quantities of nitrate in water are well known. In this research structural modification of natural clinoptilolite by isomorphic substitution was performed. Isomorphously substituted zeolite was prepar...

In 2001, Canetti and Krawczyk proposed a security model (CKmodel) for authentication protocols. They also gave an indistinguishabilitybased definition for key exchange protocols. Since then the model has almost exclusively been used for analyzing key exchange protocols, although it can be applied to authentication protocols in general. The model not only captures a large class of attacks but al...