Abstract

A system and method for key escroW cryptography for use in a system comprising a sender and a receiver. Only public escroW keys are stored in the sender and the receiver. The sender encrypts a message using a secret session key (KS), and generates a leaf veri? cation string (LVS) by combining an unique program identi? er (UIP), a public portion of a program unique key (KUpub), and a signature. The sender encrypts the KS using the KUpub to generate a? rst encrypted session key (EKS), and generates a? rst laW enforcement access? eld (LEAF) by encrypting a combina tion of the? rst EKS and the UIP With a copy of a public portion of a family key (KFpub) stored in the sender. The encrypted message, the LVS, and the? rst LEAF are trans mitted from the sender to the receiver. The receiver stores therein a public portion of the KEPF key (KEPFpub). The receiver extracts the UIP, KUpub, and the signature from …

Date

September 21, 1999

Authors

SB Lipner, DM Balenson, CM Ellison, ST Walker

Inventors

Steven B Lipner, David M Balenson, Carl M Ellison, Stephen T Walker

Patent_office

US

Patent_number

5956403

Application_number

08874459