Patent ID: 8856640

Claim:
A computer-implemented method for electronically signing an electronically stored document comprising the steps of: applying, by one or more processors, a first electronic signature to the electronically stored document to produce an initial signed version of the electronically stored document, wherein the first electronic signature includes information that associates the first electronic signature with the initial signed version of the electronically stored document; subsequent to applying the first electronic signature to the electronically stored document, modifying, by the one or more processors, the initial signed version of the electronically stored document thereby producing a first revision of the electronically stored document; applying, by the one or more processors, a second electronic signature to the first revision of the electronically stored document, wherein the second electronic signature includes information that associates the second electronic signature with the first revision of the electronically stored document, such that the first revision of the electronically stored document includes both the first electronic signature and the second electronic signature, and providing a user with the ability to view a revision history of the electronically stored document while viewing the electronically stored document, wherein the first electronic signature expires after a pre-determined period of time, and wherein the electronically stored document is simultaneously accessed by a first user associated with the first electronic signature and a second user associated with the second electronic signature.