Optimistic protocol for certified electronic mail with verifiable TTP

摘要

Highlights•We present an optimistic protocol for certified electronic mail with a verifiable TTP.•Evidence of the behavior of all parties is produced and can be used to state who was dishonest.•The proposed protocol is suitable to be deployed on the current Internet e-mail infrastructure.•We use standardized protocols for secure email such as MIME and CMS.AbstractA large number of certified email proposals have been published over the last thirty years. Many use a trusted third party (TTP) to guarantee the core security property: fairness; however, the verifiability of this TTP has not received enough attention. In fact, we have not been able to find a complete proposal for optimistic certified email with verifiable TTP, which meets the fairness and timeliness requirements. Moreover, only a few papers discuss the deployment of the solutions proposed. Here, we present an optimistic protocol for certified electronic mail with a verifiable TTP. We prove its feasibility by discussing an implementation of the proposal that does not modify the core network for Internet mail and operates using the current standardized email protocols.