Secure delegation of services through proxy signature with revocation

Abstract

The trusted delegation of services requires an effective synchronised and verifiable signature scheme to convince the authorisation of involving entities in the delegation processes. The proxy signature scheme enables an original signer to delegate her signing capability to a proxy signer in a secure manner. In this paper, we present a controlled delegation of generating a proxy signature using a control entity (mediator). The mediator controls the delegation capability of the proxy signer for making the signature even before/after the delegation period. We propose a new construction of proxy signature with revocation by using a mediator that controls the delegation capability and authorisation of the proxy signer. The security hardness of the proposed scheme is based on the computational bilinear Diffie-Hellman (CBDH) intractability assumption in the random oracle model. Furthermore, we verify the revocation process of our proposed scheme using model checking.