Trust Management for IPsec

IPsec is the standard suite of protocols for network-layer confidentiality and authentication of Internet traffic. The IPsec protocols, however, do not address the policies for how protected traffic should be handled at security end points. This article 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 trust-management 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. Finally, we discuss some applications of the enhanced IPsec architecture.