Time stamping system
US7650508B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 2002 |
| Grant date | Jan 19, 2010 |
| Priority date | — |
| Expiry date | Mar 2, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/3297
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A secure time stamping device uses multiple virtual clocks, each of which may be individually accessed and calibrated. A digital key is associated with each of the clocks. All of the virtual clocks use a common timer (130), with the actual clock output being generated by applying calibration information (124) for that clock to the timer (130) output. A user wishing to have a message time stamped presents that message along with information as to which virtual clock to be used at a device input (92). The appropriate calibration information (124) is then selected and the timer (130) output is compensated accordingly. The incoming message plus the resultant time are concatenated and automatically signed using the key (126) applicable to that particular virtual clock.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.