Patent US 8,412,946

A method and apparatus for creating and/or using trustworthy timestamps and certifiable clocks using logs linked by cryptographic hashes. In one embodiment, the method comprises maintaining a first, chained-hash log; associating a first clock with the chained-hash log, and entangling the first log; with a second by adding a time-stamped synchronization entry to the chained-hash log, where the synchronization entry has a second time indication associated with the second log and a hash of one or more entries in the first log.