Techniques for protection and accuracy of system time

A non-transitory computer-readable storage medium including instructions that, when executed by a processor, cause the processor to perform steps for updating system time, the steps comprising:

• determining a cumulative trustworthiness score based on one or more trustworthiness scores associated with respective one or more time sources;
• determining whether to update a system time based on a difference in time between the system time and a time from a first time source of the respective one or more time sources and the cumulative trustworthiness score;
• and
• in response to determining to update the system time, updating the system time based on the time from the first time source, wherein:
• if the cumulative trustworthiness score is greater than a first threshold, setting the system time equal to the time from the first time source;
• if the cumulative trustworthiness score is less than the first threshold but greater than a second threshold and the difference in time between the system time and the time from the first time source is greater than a third threshold, performing an iterative recovery technique using the time from the first time source;
• and
• if the cumulative trustworthiness score is less than the second threshold and the difference in time between the system time and the time from the first time source is greater than a fourth threshold, performing the iterative recovery technique using the time from the first time source.

A system, comprising:

• a memory storing an application;
• and
• a processor that is coupled to the memory and, when executing the application, is configured to:
• determine a cumulative trustworthiness score based on one or more trustworthiness scores associated with respective one or more time sources,
• determine whether to update a system time based on a difference in time between the system time and a time from a first time source of the respective one or more time sources and the cumulative trustworthiness score, and
• in response to determining to update the system time, update the system time based on the time from the first time source, wherein:
• if the cumulative trustworthiness score is greater than a first threshold, setting the system time equal to the time from the first time source;
• if the cumulative trustworthiness score is less than the first threshold but greater than a second threshold and the difference in time between the system time and the time from the first time source is greater than a third threshold, performing an iterative recovery technique using the time from the first time source;
• and
• if the cumulative trustworthiness score is less than the second threshold and the difference in time between the system time and the time from the first time source is greater than a fourth threshold, performing the iterative recovery technique using the time from the first time source, wherein the fourth threshold is greater than the third threshold.