Efficient and secure data currentness systems

摘要

Indicating data currentness includes, on any date of a sequence of dates, issuing a proof indicating the currentness status of the data during a particular time interval. The proof may be a digital signature. The time interval may be in the form of a current date and an amount of time. The proof may include a digital signature of the time interval. The proof may include a digital signature of the time interval and the data. The proof may include a digital signature of the time interval and a compact form of the data, such as a hash. Indicating data currentness may also include distributing the proofs to a plurality of unsecure units that respond to requests by users for the proofs. Indicating data currentness may also include gathering a plurality of separate pieces of data and providing a single proof for the separate pieces of data. The data may be electronic documents.

主权项

1. A method of conveying information about a document comprising:
prior to a request for document i, and for every document i of a plurality of documents, having a currentness authority, using hardware processor, 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, providing the digitally signed currentness status information Ci to a responder; 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.