A New Design of Privilege Management Infrastructure (PMIs) for Organizations Using Outsourced PKI

Authentication services provided by Public Key Infrastructures (PKI) do not satisfy the needs of many e-commerce applications. These applications require additional use of authorization services in order for users to prove what they are allowed to do. Attribute certificates have changed the way in which the authorization problem has been considered until now, and Privilege Management Infrastructures (PMI) provide the necessary support for a wide use of those certificates. Although both types of infrastructures, PKIs and PMIs, keep some kind of relation, they can operate autonomously. This fact is specially interesting for companies who have taken or will take the decision to outsource PKI services. However, outsourcing PMI services is not a good option for many companies because sometimes information contained in attribute certificates is confidential. Therefore attribute certificates must be managed very carefully and, preferably, only inside the company. In this paper we present a new design of PMI that is specially suited for those companies that outsource PKI services but still need to manage the PMI internally. The scheme provides additional advantages that satisfy the needs of intra-company attribute certification, and eliminates some of the problems associated with the revocation procedures.