The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 25, 2011
Filed:
Feb. 07, 2005
David B. Cross, Redmond, WA (US);
Duncan G. Bryce, Issaquah, WA (US);
Jianrong Gu, Bellevue, WA (US);
Kelvin Shek Yiu, Seattle, WA (US);
Monica Ioana Ene-pietrosanu, Redmond, WA (US);
David B. Cross, Redmond, WA (US);
Duncan G. Bryce, Issaquah, WA (US);
Jianrong Gu, Bellevue, WA (US);
Kelvin Shek Yiu, Seattle, WA (US);
Monica Ioana Ene-Pietrosanu, Redmond, WA (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
Systems and methods for managing multiple keys for file encryption and decryption may provide an encrypted list of previously used keys. The list itself may be encrypted using a current key. To decrypt files that are encrypted in one or more of the previous keys, the list can be decrypted, and the appropriate previous key can be retrieved. To re-key files, an automated process can decrypt any files using previous keys and encrypt them using the current key. If a new current key is introduced, the prior current key can be used to decrypt the list of keys, the prior current key can be added to the list, and the list can be re-encrypted using the new current key.