A Comparative Study of SPKI/SDSI and K-SPKI/SDSI Systems

摘要

SPKI/SDSI is a popular trust-management system which defines a formal language for expressing authorization and access-control policies and relies on an algorithm to determine when a specific request can be granted. It also provides support for delegation of authority. K-SPKI/SDSI is a trust management system in which SPKI/SDSI is used in conjunction with Kerberos. This study focuses on differences between the two systems. SPKI/SDSI has seen limited deployment because of the fact that it is PKI-based, i.e., every principal is required to have a public-private key pair. K-SPKI/SDSI overcomes this disadvantage by using Kerberos for local authentication. We also compare the performance of the two systems based on various parameters such as Time taken to authenticate, Number of key pairs required and Number of certificates generated.