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:
May. 14, 2002
Filed:
Oct. 13, 1998
Matthew W. Thomlinson, Bellevue, WA (US);
Scott Field, Renton, WA (US);
Allan Cooper, Bellevue, WA (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
Described herein is a system for protecting data from unauthorized access. The system uses a central service provider with exposed complementary interfaces: a data protect function that accepts clear data and returns an encrypted representation of the data, and a data unprotect function that accepts encrypted data and returns corresponding clear or unencrypted data. In addition, a user-readable description is optionally packaged with the encrypted data. Different encryption providers can be registered to perform actual encryption and decryption. A default encryption provider performs encryption and decryption based on a user logon secret such as a password. The default encryption provider also accepts additional entropy from calling application programs. The default encryption provider utilizes a multi-level key encryption scheme to minimize the amount of encryption that has to be re-done when the user changes a password. In addition, data recovery information is escrowed so that keys can be recovered when a user's password is changed.