Patent Document ID: 8949607
Application ID: 13889764

Base Claim:
1. A method of verifying if a request for a second digital document originates from a reference within an authentic copy of a first digital document, the method comprising: a first computer sends the first digital document to a second computer via a computer network; the second computer receives a possibly tampered version of the first digital document via the computer network; the first computer computes a first authentication tag on at least a part of the first digital document; the second computer computes a second authentication tag on at least a part of the possibly tampered version of the first digital document; the second computer sends the request for the second digital document referenced in the possibly tampered version of the first digital document to the first computer via the computer network, the request including the second authentication tag; the first computer receives a possibly tampered version of the request and deducts the second authentication tag; the first computer considers the possibly tampered version of the request as originating from an authentic copy of the first digital document if the second authentication tag is equal to the first authentication tag; and the first computer causes the second document to be sent to the second computer only if the second authentication tag is equal to the first authentication tag.

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Claim 2:
2. The method according to claim 1 further comprising: the second computer collects the digital data to be included in a request for the second digital document; the second computer computes a third authentication tag on at least a part of the digital data; the second computer includes the digital data and the third authentication tag in the request sent to the first computer; the first computer also deducts the digital data and the third authentication tag from the possibly tampered version of the request; the first computer computes a fourth authentication tag on at least a part of the digital data attached to the possibly tampered version of the request; the first computer considers the digital data attached to the possibly tampered version of the request as authentic if the third authentication tag is equal to the fourth authentication tag.