Hybrid computer security clock

• US 8,281,178 B2
• Filed: 04/14/2009
• Issued: 10/02/2012
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Thibadeau, Robert H.
• Primary Examiner(s): CONNOLLY, MARK A
• Application Number:
  US12/423,662
• Publication Number:
  US 20090235109A1
• Time in Patent Office: 1,267 Days
• Field of Search: 713/189, 713/500, 713/502, 726/1, 726/29, 726/30
• US Class Current: 713/500
• CPC Class Codes: G06F 1/14 Time supervision arrangements, e.g. real time clock

Abstract

A clock object is provides, which includes a clock time and a monotonic time that are readable by the electronic device. The monotonic time is incremented every read of the monotonic time from the clock object. The clock object can also include an indication of a level of trust of the clock time.

Claims

1. A device comprising:

a processor configured to implement a clock object including;

a clock time that is readable by an electronic device; and

a trust indicator indicative of a trust level of the clock time, wherein there are more than two trust levels that may be indicated and the clock object is adapted to provide the clock time and the trust indicator to the electronic device.

2. The device of claim 1 wherein:

the clock time comprises at least one kind of a high trust clock time and a low trust clock time, wherein the high trust clock time is more authoritative than the low trust clock time; and

in response to a clock read request, the clock object is adapted to return at least one of the high trust clock time and the low trust clock time and the trust indicator to the electronic device.

3. The device of claim 2 further comprising:

an interface for the device to communicate with the electronic device;

a memory to store the clock object; and

wherein the trust indicator indicates the kind of clock time being returned.

4. The device of claim 2 and further comprising a memory storing a clock database, which stores the high trust clock time and the low trust clock time, if available, and an indication of whether the database contains the high trust clock time and whether the database contains the low trust clock time.

5. The device of claim 1, wherein the clock object further comprises:

a monotonic time, wherein the monotonic time is incremented for every read of the clock time from the clock object; and

upon a reset of the clock object, the clock object is adapted to adjust the monotonic time.

6. The device of claim 1 and further comprising:

a memory storing a clock database, which comprises;

a static set time representative of a source time received from a clock source; and

a timer, which increments a timer value, wherein the clock time is a function of the set time and the timer value.

7. The device of claim 1 and further comprising:

a memory storing a clock database, which comprises;

a static set time representative of a source time read from a clock source; and

a lag time representative of a delay in successfully recording the set time in the clock database.

8. The device of claim 1 wherein the trust indicator is indicative of one of multiple trust levels including a first trust level, a second trust level, and a third trust level, the first trust level indicates a lower trust compared to the second trust level that indicates a higher trust compared to the first trust level, and the third trust indicator indicates no trust.

9. A device comprising:

a clock object having a clock time that is readable by an electronic device;

the clock object provides an indicator of a type of clock time from multiple available clock times to the electronic device; and

the clock object provides a monotonic count value in addition to the clock time to the electronic device.

10. The device of claim 9 further comprising an interface coupled to the clock object to receive a request from the electronic device to provide the clock time and the interface adapted to provide the indicator of the type of clock time to the electronic device.

11. The device of claim 9 further comprising the indicator of the type of clock time indicates of a trust level of the clock time.

12. The device of claim 9 further comprising the clock object provides a clock time of an indicated clock type.

13. The device of claim 12 further comprising the clock object provides a monotonic count value to the electronic device.

14. The device of claim 13 further comprising the clock object provides a lag time to the electronic device, the lag time representing a delay between the clock time and an actual time.

15. The device of claim 9 further comprising the indicator of the type of clock time indicates multiple types of clock time and the clock object provides multiple clock times associated with the multiple types of clock time to the electronic device.

16. A device comprising:

a clock function adapted to provide a clock time to an electronic device; and

the clock function is adapted to provide a monotonic count value that is not dependent on time and is distinct from the clock time to the electronic device.

17. The device of claim 16 further comprising the clock function is adapted to provide an indicator of a type of clock time, provide the clock time associated with the indicator, and the indicator indicates a trust level of the clock time.

18. The device of claim 17 further comprising the trust level is one of multiple trust levels including a first trust level, a second trust level, and a third trust level, where the first trust level indicates a lower trust compared to the second trust level and the second trust level indicates a lower trust compared to the third trust level.

19. The device of claim 16 further comprising the count value is a monotonic count value and the clock function is adapted to increment the monotonic count value based on activity of the clock function.