Personal computer system and methods for proving dates in digital data files
DCFirst Claim
1. 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.
1 Assignment
Litigations
0 Petitions
Accused Products
Abstract
A personal computer (PC) system and methods for proving dates of digital data files, which are accessed, created, modified, received, or transmitted by the PC includes a trusted time source in a tamperproof environment, a first subsystem for saving the file at a moment in time, a second subsystem for retrieving from the trusted time source a date and a time corresponding to the moment in time, a third subsystem for appending the date and the time retrieved from the trusted time source to the saved file, a fourth subsystem for signing the saved file with the date and the time retrieved from the trusted time source appended thereto, a fifth subsystem means for hashing the signed file to produce a digest, a sixth subsystem for signing the digest with a key to produce a certificate, a seventh subsystem for appending the certificate to the saved file, and an eighth subsystem for saving the file with the certificate appended thereto. The trusted time source is a real time clock, which is not resettable, is independent of any system clock of the PC, and is installed locally relative to the PC.
234 Citations
34 Claims
-
1. 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. A method of maintaining a digital data file in a personal computer, comprising:
-
providing a trusted time source in the personal computer, wherein said trusted time source provides 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;
receiving a request to save said digital data file from a user;
saving said digital data file at a moment in time;
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;
appending said date and said time retrieved from said trusted time source to said digital data file;
signing said digital data file with said date and said time retrieved from said trusted time source appended thereto;
hashing said digital data file to produce a digest;
signing said digest with a key to produce a certificate;
appending said certificate to said digital data file;
saving said file with said certificate appended thereto; and
verifying trust in the content of said digital data file with said certificate appended thereto. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
-
-
29. A method of maintaining trust in content of a first digital data file and content of a second digital data file in a personal computer, comprising:
-
providing a trusted time source in the personal computer, wherein said trusted time source provides a certifiable time for an unalterable time stamp, wherein said certifiable time confirms at least one of said first digital data file'"'"'s access, creation, modification, receipt, or transmission;
receiving a request to save said first digital data file from a user;
saving said first digital data file at a first moment in time;
retrieving from said trusted time source a date and a time corresponding to said first moment in time, wherein said moment in time is substantially a current time of said trusted time source corresponding to receipt of said request;
appending said date and said time retrieved from said trusted time source to said first digital data file;
signing said first digital data file with said date and said time retrieved from said trusted time source appended thereto;
hashing said first digital data file to produce a first digest;
signing said first digest with a first key to produce a first certificate;
appending said first certificate to said first digital data file;
saving said first digital data file with said first certificate appended thereto;
verifying trust in the content of said first digital data file with said certificate appended thereto; and
appending said first digital data file, with said first certificate appended thereto, to said second digital data file. - View Dependent Claims (30, 31, 32, 33, 34)
-
Specification