Electrical computers and digital processing systems: support – Multiple computer communication using cryptography – Particular communication authentication technique
Reexamination Certificate
1999-12-10
2009-02-10
Vu, KimYen (Department: 2135)
Electrical computers and digital processing systems: support
Multiple computer communication using cryptography
Particular communication authentication technique
C713S155000, C713S170000, C713S181000, C713S501000, C713S502000, C705S050000, C705S051000
Reexamination Certificate
active
07490241
ABSTRACT:
A method for time stamping a digital document is disclosed. The document originator creates a time stamp receipt using the document and the current time. The time stamp receipt is submitted to a time stamping authority having a trusted clock. The time stamping authority validates the time stamp receipt by comparing the time value specified in the time stamp receipt to the current time. If the time value specified in the time stamp receipt is within a predetermined time window, the time stamping authority cryptographically binds the time value and document, or the time value and some representation of the document, e.g., by signing the time stamp receipt with its private signature key.
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Matyas, Jr. Stephen M.
Peyravian Mohammad
Roginsky Allen
Zunic Nevenko
Coats & Bennett P.L.L.C.
Dada Beemnet W
International Business Machines - Corporation
Vu Kim-Yen
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