Determining the integrity of a computing device

A non-transitory computer readable medium for storing a timestamp verifying program that determines whether a system clock of a computer has been altered, the non-transitory computer readable medium configured to allow the computer to:

• start a loop having a predetermined time period;
• capture an initial system time at the start of the loop;
• capture an ending system time at the end of the loop;
• calculate a difference in time between the initial system time and the ending system time;
• determine whether the calculated difference is the same as other calculated differences for other loops having the predetermined time period;
• and
• determine that the system clock has been altered when the calculated difference is not the same as the other calculated differences.

A system comprising:

• a device configured to obtain information related to an event;
• and
• a computer connected to the device, wherein the computer comprises a system clock for providing a system time, and wherein the computer is configured to:
• capture an initial system time and an initial counter value when a device is connected to the computer, wherein the initial system time and the initial counter value are based on the system clock;
• receive information obtained by the device;
• capture a current system time and a current counter value when the information is obtained, wherein the current system time and the current counter value are based on the system clock;
• determine a first time-calculation representing a difference in time between the initial system time and the current system time;
• determine a second time-calculation representing a difference between the initial counter value and the current counter value;
• compare the first time-calculation and the second time-calculation to determine that a mismatch exists;
• and
• determine that the system clock has been altered based on the comparison.