Method and apparatus for verifying the integrity of a file stored separately from a computer
AssigneeApple Computer, Inc.
InventorPatrick Dyson
Life of this patent
Estimating the term…
Abstract
A method and apparatus for verifying a file stored separately from a computer to be identical with a previous version of the file, before using the file. This verification is done by following a defined procedure to generate a first identifier based on the contents of the previous version of the file, storing this identifier locally on the computer, and storing the file at a separate storage location. Then, at a later time, an unverified second file is retrieved from the separate storage location, the same defined procedure is followed to generate a second identifier, and the first and second identifiers compared to identify a match that verifies the integrity of the second file.
Claims6
A method for verifying the integrity of a file stored separately from a computer, comprising:
- preparing a first file for said computer, said file including a header and a body, said header including a selected number portion;
- following a defined mathematical procedure to generate a unique first identifier based on the contents of said first file;
- storing said first identifier on said computer;
- encrypting said selected number portion of said header of said first file with a password stored on said computer;
- storing said first file at a storage location separate from said computer;
- at a later time, retrieving from said storage location an unverified second file;
- decrypting said selected number portion of said header of said unverified second file with said password stored on said computer;
- following said defined mathematical procedure, generating a unique second identifier based on the contents of said unverified second file;
- comparing said first and said second identifiers to identify a possible match which would verify the integrity of said second file;
- and
- using the verified said second file on said computer.
An apparatus for verifying the integrity of a file that has been stored separately from a computer, comprising:
- a computer including a preparation means, processing means, storage means, and encryption means, wherein
- said preparation means for preparing a first file for said computer, said file including a header and a body, said header including a selected number portion;
- said processing means for following a defined mathematical procedure to generate a unique first identifier based on the contents of said first file;
- said storage means storing said first identifier on said computer;
- and
- said encryption means for encrypting said selected number portion of said header of said first file with a password stored on said computer;
- separate storage means for storing said first file at a storage location separate from said computer;
- and at a later time, returning to said computer from said storage location an unverified second file;
- said computer further comprising decryption means, comparer means and execution means, wherein
- said decryption means for decrypting said selected number portion of said header of said unverified second file with said password stored on said computer;
- said processing means for following said defined mathematical procedure to generate a unique second identifier based on the contents of said unverified second file;
- said comparer means for comparing said first and said second identifiers, to identify a match which verifies the integrity of said second file;
- and
- said execution means for using the now-verified said second file on said computer.
A method for verifying the integrity of a file stored separately from a computer, comprising:
- preparing a first file for use on said computer;
- executing a defined mathematical procedure to generate a unique first identifier based on the contents of said first file;
- storing said first identifier on said computer;
- encrypting a selected number portion of said first file with a password stored on said computer;
- storing said first file at a storage location separate from said computer;
- at a later time, retrieving from said storage location an unverified second file;
- decrypting a same said selected number portion of said unverified second file with said password stored on said computer;
- executing said defined mathematical procedure to generate a unique second identifier based on the contents of said unverified second file;
- comparing said first and said second identifiers to identify a possible match that verifies the integrity of said second file;
- and
- using the verified said second file on said computer.
Dependencies are inferred from the claim text.