Digital document time-stamping with catenate certificate
First Claim
1. A method of certifying the temporal sequence of digital documents in a series of such documentscharacterized in that said method comprises:
- a) generating a digital representation of a specified one of the documents in said series; and
b) generating a catenate certificate value representation for said specified document by applying a selected deterministic function algorithm to a catenation comprising said digital representation and the catenate certificate value representation for the document immediately prior in said series to said specified document.
13 Assignments
0 Petitions
Accused Products
Abstract
A system for time-stamping a digital document, for example any alphanumeric, video, audio, or pictorial data, protects the secrecy of the document text and provides a tamper-proof time seal establishing an author'"'"'s claim to the temporal existence of the document. Initially, the document may be condensed to a single number by means of a one-way hash function, thereby fixing a unique representation of the document text. The document representation is transmitted to an outside agency where the current time is added to form a receipt. The agency then certifies the receipt by adding and hashing the receipt data with the current record catenate certificate which itself is a number obtained as a result of the sequential hashing of each prior receipt with the extant catenate certificate. The certified receipt bearing the time data and the catenate certificate number is then returned to the author as evidence of the document'"'"'s existence. In later proof of such existence, the certificate is authenticated by repeating the certification steps with the representation of the alleged document, the alleged time data, and the catenate certificate number appearing in the agency'"'"'s records immediately prior to the certificate number in question. Only if the alleged document is identical to the original document will the original and repeat certificate numbers match.
443 Citations
13 Claims
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1. A method of certifying the temporal sequence of digital documents in a series of such documents
characterized in that said method comprises: -
a) generating a digital representation of a specified one of the documents in said series; and b) generating a catenate certificate value representation for said specified document by applying a selected deterministic function algorithm to a catenation comprising said digital representation and the catenate certificate value representation for the document immediately prior in said series to said specified document. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of time-stamping a digital document which comprises transmitting a digital representation of said document to an outside agency, creating at said outside agency a receipt comprising a digital representation of then current time and at least a portion of a digital representation of said digital document, and certifying said receipt at said outside agency
characterized in that the certifying of said receipt comprises: -
a) concatenating a digital representation of said receipt with a representation of a prior catenate certificate value to form a composite; and b) generating a catenate certificate value for said receipt by applying a selected deterministic function algorithm to said composite. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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Specification