SYSTEMS, METHODS, SOFTWARE, AND COMPONENTS USING TAMPER-PROOF REAL-TIME CLOCK
The write-access control line for an RTC is combined with a clear line for an RTC signature register, so that changes to the RTC will cause subsequent reads to return an invalidity flag.
1 . A device, comprising:
a real-time clock configured to maintain and provide a system time; and
signature storage having an invalidation control line connected to the real-time clock,
wherein the signature storage includes a digital signature that is compared to a signature input for determining whether the invalidation control line forces the signature storage into an invalid state.
2 . The device of claim 1 , wherein the digital signature is not available as data output.
3 . The device of claim 1 , wherein if the digital signature is equal to the signature input, the signature storage is forced into a valid state.
4 . The device of claim 1 , wherein if the digital signature is not equal to the signature input, the signature storage is forced into an invalid state.
5 . The device of claim 1 , further comprising instruction execution logic operable to execute a plurality of software instructions.
6 . The device of claim 1 , further comprising validation logic to check the digital signature.
7 . The device of claim 1 , wherein the digital signature is generated based on a unique hardware-encoded value.
8 . A method comprising
generating a digital signature for a real-time clock configured to maintain and provide a system time;
storing the digital signature in signature storage having an invalidation control line connected to the real-time clock, and
comparing the digital signature to a signature input for determining whether the invalidation control line forces the signature storage into an invalid state.
9 . The method of claim 8 , wherein the digital signature is not available as data output.
10 . The method of claim 8 , wherein if the digital signature is equal to the signature input, the signature storage is forced into a valid state.
11 . The method of claim 8 , wherein if the digital signature is not equal to the signature input, the signature storage is forced into an invalid state.
13 . The method of claim 8 , wherein the comparing is performed via validation logic.
14 . The method of claim 8 , wherein the digital signature is generated based on a unique hardware-encoded value.
14 . The method of claim 8 , wherein the digital signature is generated based on a real-time clock value.
15 . A non-transitory computer readable medium comprising instructions for:
generating a digital signature for a real-time clock configured to maintain and provide a system time;
storing the digital signature in signature storage having an invalidation control line connected to the real-time clock, and
comparing the digital signature to a signature input for determining whether the invalidation control line forces the signature storage into an invalid state.
16 . The non-transitory computer readable medium of claim 15 , wherein the digital signature is not available as data output.
17 . The non-transitory computer readable medium of claim 15 , wherein if the digital signature is equal to the signature input, the signature storage is forced into a valid state.
18 . The non-transitory computer readable medium of claim 15 , wherein if the digital signature is not equal to the signature input, the signature storage is forced into an invalid state.
19 . The non-transitory computer readable medium of claim 15 , wherein the digital signature is generated based on a unique hardware-encoded value.
20 . The non-transitory computer readable medium of claim 15 , wherein the digital signature is generated based on a real-time clock value.