US Patent 7409557 System and method for distributing trusted time

Systems and methods for distributing trusted time, including trusted dates with digital data files, which are accessed, created, modified, received, or transmitted by devices that include a trusted time source in a tamperproof environment. The system includes one or more subsystems for providing trusted time for a moment in time. The trusted time source may be a real time clock, which is not resettable, is independent of any system clock of the devices, and where one or more devices may contribute to the distribution of trusted time among each other.