IPsec is the standard suite of protocols for networklayer confidentiality and authentication of Internet traffic. The IPsec protocols, however, do not address the policies for how protected traffic should be handled at security endpoints. This paper introduces an efficient policy management scheme for IPsec, based on the principles of trust management. A compliance check is added to the IPsec architecture that tests packet filters proposed when new security associations are created for conformance with the local security policy, based on credentials presented by the peer host. Security policies and credentials can be quite sophisticated (and specified in the trustmanagement language), while still allowing very efficient packet-filtering for the actual IPsec traffic. We present a practical, portable implementation of this design, based on the KeyNote trust-management language, that works with a variety of Unix-based IPsec implementations.
Matt Blaze, John Ioannidis, Angelos D. Keromytis