A multi-server queueing system with two types of requests and preemptive priority one type is considered as a model cell cognitive radio under practical suggestions about the arrival flows. hysteresis strategy for server reservation suggested to mitigate effect interruption service low requests. Under arbitrarily fixed values sets thresholds defining this strategy, behavior described by level-d...

Most of the password based authentication protocols make use of the single authentication server for user’s authentication. User’s verifier information stored on the single server is a main point of susceptibility and remains an attractive target for the attacker. On the other hand, multi-server architecture based authentication protocols make it difficult for the attacker to find out any signi...

Recently, Li et al. analyzed Lee et al.’s multi-server authentication scheme and proposed a novel smart card and dynamic ID based remote user authentication scheme for multi-server environments. They claimed that their scheme can resist several kinds of attacks. However, through careful analysis, we find that Li et al.’s scheme is vulnerable to stolen smart card and offline dictionary attack, r...

This investigation deals with multi server queue with balking. The customers arrive in poisson fashion and independent of time, under the assumption that system is initially empty. The number of customers in the system is stochastically increasing and distributed in steady state (stationary state) as required. The expressions for the measure of the speed of convergence from transient state to s...

There are many challenges concerning online privacy. Private information retrieval (PIR) tries to find solution to following problem. Server has a database of n records and client wants to retrieve w-th record without revealing w to the server. PIR schemes can be described for single-server and multi-server case (where each server holds identical copy of database). Current report reviews a mult...

Since the number of server providing the facilities for the user is usually more than one, the authentication protocols for multi-server environment are required for practical applications. Most of password authentication schemes for multi-server environment are based on static ID, so the adversary can use this information to trace and identify the user's requests. It is unfavorable to be appli...

With the need and adoption of link aggregation where multiple links exist between two adjacent nodes in order to increase transmission capacity between them, there arise the problems of service guarantee and fair sharing of multiple servers. Although a lot of significant work has been done for single-server scheduling disciplines in the past years, not much work is available for multi-server sc...