DHCP Authentication Using Certificates

In this paper, we describe several methods of DHCP authentication. We propose an extension to DHCP protocol in order to allow a strict control on equipments by using a strong authentication. This extension, called E-DHCP (Extended-Dynamic Host Configuration Protocol) is based on two principles. The first one is the defimition of a new DHCP option that provides simultaneously the authentication of entities (client/server) and DHCP messages. The technique used by this option is based mainly on the use of asymmetric keys encryption RSA, X.509 identity certificates and attribute certificates. The second principle is the attribution of PMI (Privilege Management Infrastructure) attribute authority server functionalities to DHCP server. This server creates an attribute certificate to the client, which ensures the relation between the identity certifiicate of the client and the allocated IP address. This attribute certificate will be then used in the access control.