Time stamping method using time delta in key certificate
First Claim
Patent Images
1. A method for time stamping a document comprising:
- receiving a time stamp receipt at an outside agency, said time stamp receipt including identifying data associated with said document and a time indication;
computing the age of said time stamp receipt based on said time indication;
signing said time stamp receipt at said outside agency using a secret signature key, said signature key selected from a group of signature keys based on the computed age of said time stamp receipt.
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Abstract
A method for time stamping a digital document is disclosed. The document originator creates a time stamp receipt by combining the document and a digital time indication. The time stamp receipt is submitted to a time stamping agent having a trusted clock. The time stamping agent optionally validates the time stamp receipt and then computes the age of the time stamp receipt. If valid, the time stamping agent certifies the time stamp receipt by signing the time stamp receipt with a private signature key. The private signature key is selected from a group of signature keys by the time stamping agent based on the computed age of the time stamp receipt.
43 Citations
17 Claims
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1. A method for time stamping a document comprising:
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receiving a time stamp receipt at an outside agency, said time stamp receipt including identifying data associated with said document and a time indication;
computing the age of said time stamp receipt based on said time indication;
signing said time stamp receipt at said outside agency using a secret signature key, said signature key selected from a group of signature keys based on the computed age of said time stamp receipt. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for time stamping a document comprising:
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creating a time stamp receipt including identifying data associated with said document and a time indication;
transmitting said time stamp receipt to an outside-agency for certification;
computing the age of said time stamp receipt at said outside agency;
signing said time stamp receipt at said outside agency using a secret signature key, said secret signature key selected from a group of signature keys based on the computed age of said time stamp receipt; and
transmitting said signed time stamp receipt from said outside agency to a designated party. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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Specification