Patent ID: 6898709

Claim:
A personal computer system for maintaining trust in content of a digital data file, comprising: a personal computer having installed therein a trusted time source to provide a certifiable time for an unalterable time stamp, wherein said certifiable time confirms at least one of said digital data file's access, creation, modification, receipt, or transmission; means for receiving a request to save said digital data file from a user; first means for saving said digital data file at a moment in time; means for retrieving from said trusted time source a date and a time corresponding to said moment in time, wherein said moment in time is substantially a current time of said trusted time source corresponding to receipt of said request; first means for appending said date and said time retrieved from said trusted time source to said digital data file; first means for signing said digital data file with said date and said time retrieved from said trusted time source appended thereto; means for hashing said digital data file to produce a digest; second means for signing said digest with a key to produce a certificate; second means for appending said certificate to said digital data file; second means for saving said digital data file with said certificate appended thereto; and means for verifying trust in the content of said digital data file with said certificate appended thereto.