Stephen D Seymour, 435 Mauweehoo Hl, Sherman, CT 06784

5982898, Nov 9, 1999

Mar 7, 1997

8/812640

Yung-Kao Hsu - Aberdeen NJ
Stephen Seymour - Bound Brook NJ

AT&T Corp. - New York NY

H04L 900

380 23

An improved secure communication arrangement separates the tasks of identity verification and certificate issuing, which allows a disassociating of the long-term binding between Alice and her public/private key pair. This is accomplished by a registration authority issuing a password to Alice once it is satisfied of Alice's bona fide. Thereafter, whenever Alice wishes to communicate with Bob, she contacts a certification authority, identifies herself with the password and obtains a private key and a corresponding short-lived certificate. The certificate typically includes Alice's name and a public key in plaintext, and a signature. The signature is derived by hashing the plaintext portion of the certificate to obtain a value, and encrypting the value with the CA's private key. She then contacts Bob, submits her certificate, Bob performs the same hashing function to obtain a value, decrypts the signature with CA's public key to obtain a decrypted value, and compares the value Bob created with the decrypted value. If the two match, Bob is assured that the person submitting the certificate may be communicated with by using the public key included in the certificate.