Secure time functionality for a wireless device
The present invention is related to a wireless transmit/receive unit (WTRU) for providing advanced security functions. The WTRU includes trusted platform module (TPM) for performing trusted computing operations; and a secure time component (STC) for providing a secure measurement of a current time. The STC and the TPM are integrated to provide accurate trusted time information to internal and external to the WTRU. The STC may be located on an expanded a subscriber identity module (SIM), on the WTRU platform, or two STCs may be used, one in each location. Similarly, the TPM may be located on an expanded SIM, on the WTRU platform, or two TPMs may be used, one in each location. Preferably, the STC will include a real time clock (RTC); a tamper detection and power failure unit; and a time report and sync controller.
1. A wireless communications device comprising:
a clock for maintaining a current time value, wherein the wireless communications device is configured to re-synchronize the clock with a secure time server to which the wireless communication device is coupled via a network; and
a trust platform module (TPM) comprising a memory protected by the TPM, the TPM being further configured to retrieve from the clock a last storable record of the current time value prior to a failure of power in the wireless communications device and to save the retrieved record in the memory protected by the TPM prior to the failure of power.
2. The wireless communications device of claim 1 , further comprising an audit logging facility.
3. The wireless communications device of claim 1 further comprising a subscriber identity module (SIM).
4. The wireless communications device of claim 3 wherein the TPM is located on the SIM.
5. The wireless communications device of claim 3 wherein the clock is part of a secure time component (STC) that resides on the SIM.
6. The wireless communications device of claim 1 , further comprising a power failure unit configured to detect a failure of power in the wireless communications device and to alert the TPM of the power failure.
7. The wireless communications device of claim 6 , wherein the power failure unit is configured to store a charge such that the record of the current time value may be securely stored in the memory protected by the TPM upon detection of the power failure.
8. The wireless communications device of claim 1 , wherein the secure time server is part of an operator network.