
US Patent No: 5,189,700
Number of patents in Portfolio can not be more than 2000
Devices to (1) supply authenticated time and (2) time stamp and authenticate digital documents
Stats
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Feb 23, 1993
Issued date -
Jan 7, 1991
filing date -
07/637,675
serial no -
Expired
status
Importance
Abstract
A device to provide authenticated time includes a clock and an encryption circuit enclosed by a seal with a controller for producing an encrypted authentication code of the time read for the clock upon request. An authentication device number can be combined with the time data before encryption. Additionally, the device can receive text or other data (either complete text or a hash of a text document) and combine the text data with the time data before encryption so that the encrypted authentication code is formed from the combined data. Optionally the device can produce, time stamp and authenticate the hash of data. Other material such as user and/or device sequence number and/or a random number can be included in the data used in forming the encrypted authentication code.
First Claim
Related Publications
International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
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