Patent ID: 7657751
Filing Date: 2010-02-02
Classification: H04L

Abstract:
1. A method of conveying currentness information about a document that is one of a plurality of documents, comprising: at every date j of a sequence of dates, and for every document i of the plurality of documents, having a currentness authority compute individual currentness status information Ci about i by digitally signing information identifying i, date j and an indication whether i continues to be valid, or is obsolete, or is suspended, wherein the currentness authority computes the individual currentness status information Ci independently of a request for the document i; providing the digitally signed currentness status information Ci to a responder, wherein the responder is a non-trusted relay of the digitally signed currentness status information Ci; for each document i in a plurality of documents, having the responder store the latest received Ci; and in response to an inquiry about currentness status of document i, having the responder provide the latest received Ci.