Certified e-mail protocol in the ID-based setting

ID-based public key cryptosystem can be a good alternative for certificate-based public key setting, especially when efficient key management and moderate security are required. Certified e-mail protocols provide for fair exchange in which the intended recipient gets the e-mail content if and only if the mail originator receives an irrefutable receipt for the e-mail. In this paper we present an optimistic certified e-mail protocol in an ID-based setting. The protocol makes use of verifiable encryption of ID-based digital signatures as building blocks. We offer arguments for the fairness, efficiency, and provable security of our new protocol.