Patent ID: 6584565
Filing Date: 2003-06-24
Classification: H04L

Abstract:
A method for enabling long term verification of digital signatures, comprising the steps of:submitting a source document or digest thereof to a signature verification entity; using a long term signature verification server to store a public key infrastructure (PKI) state necessary to re-create a signature verification process at a later time relative to said document at a selected archival time, wherein classes of PKI state information may include one or more of: certificate chain from one entity to another, including certification authorities (CAs) and the end entities; certificate revocation lists (CRLs), one for each CA in certificate chain; certificate practice statements; attribute certificates; policy constraints; trust information; and date and time; using said archived PKI state in said long term signature verification server to precisely re-create said PKI state to execute exactly said signature verification process as it was or would have been performed earlier relative to said document at a selected time after a certificate associated with said signature has expired; wherein the time over which a digital signature associated with said document can be verified is extended beyond expiration of any or all of any certificates upon which that signature depends; and wherein the selected archival time used as the basis for subsequent re-creation of a signature verification process is the time when said source document was signed by its originator.