| 摘要 |
<p>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.</p> |
