Access revocation and prevention of false repudiation in secure email exchanges

A secure email protocol (SEP) is introduced to provide a decentralized means of revoking trust access and preventing false repudiation. Verification of the exchange of a message between sender and recipient is accomplished through an identification cookie (IC) and an encryption key (EK) handled by Verification and Authentication Agents (VAAs). The communicated narrative is encrypted by the EK. The augmented message is then encrypted again using one of the widely available encryption algorithms, such as the Pretty Good Privacy (PGP) scheme, and sent to the addressee. The extracted IC serves as a label which the addressee uses to obtain the EK from the sender´s VAA. Once the addressee possesses the message´s EK, s/he is able to decrypt the narrative, verify that the IC is correct, and the process is complete. Quick revocation of access privileges and cancellation of old messages is achieved by deleting ICs not requested by the addressee. The structure of the message body is written in the eXtensive Markup Language (XML) to take advantage of the language´s extendibility and compatibility features