Performability modelling of a Kerberos server with Frequent Key Renewal under pseudo-secure conditions for increased security

This paper presents a modelling approach for performability evaluation of Kerberos servers which dynamically renew keys under pseudo-secure conditions in order to significantly reduce the chances of potential intruders. Since the proposed approach involves temporary interruption to link/server access, it has implications in terms of performance degradation. An analytical method is used to evaluate the cost in terms of the degradation of system performance. Unlike previous studies, the failures of the servers are considered together with link/server interruptions for renewals. Therefore the model presented considers the system for exact performability evaluation. Numerical results are provided in order to analyse the effects of renewal times, times between renewals and failures of the server.