| 摘要 |
A device for providing, for a limited period, a trusted service, such as trusted timestamping, without direct connection to a trusted service provider which guarantees the service provided by the device, has a tamper-proof enclosure containing a clock or other trusted service module, a protected memory containing a digital certificate and a private key, a battery for maintaining power to the clock and the protected memory, a processor and an interface for connection to a user's computer or workstation. Upon receipt of a request from the workstation via the interface, the processor obtains the current time from the clock and assembles it into a timestamp incorporating the digital certificate and signed using the private key. The timestamp is then supplied to the user via the interface. A radio receiver module may be included to enable adjustment of the clock in accordance with broadcast time signals. A usage limiter is provided to prevent the device from providing the trusted service outside the limited period of time (or limited number of permitted usages). |
