Patent ID: 8132261

Claim:
A computer-implemented method employing a microprocessor for controlling access to a document, the method comprising: determining, using the microprocessor, an access right for a user, the access right indicating whether the user has permission to read, write, execute, and/or delete; building a member definition comprising a member identifier, an access control list comprising a list of access rights of the user, a private key of a key pair for use in encrypting the document, and a digital signature, and associating the member definition with the user; linking the member definition to a first data portion of a document, wherein the document has the first data portion and a second data portion; receiving a request from the user to access the document; comparing the request with the access right; allowing access to only the first data portion in accordance with the access right; and denying access to the second data portion in accordance with the access right, wherein the denying access comprises at least one of logging information regarding the denial of access to the second data portion, and notifying security personnel regarding the denial of access to the second data portion; the method further comprising: determining a second access right for the user; building a second member definition using the second access right; and linking the second member definition to the second data portion of the document.