Cryptography system and method for providing cryptographic services for a computer application

USRE38070E1 · kind E1 · reissue

Assignee

• Microsoft Corporation · US

Inventors

• Terrence Spies · Redmond, US
• Jeffrey F. Spelman · Duvall, US
• Daniel R. Simon · Redmond, US

Key dates

• Filing date: Aug 30, 1999
• Grant date: Apr 8, 2003
• Expiry date: Aug 30, 2019

Classification

• Technology area (CPC —): General

Abstract

A cryptography system architecture provides cryptographic functionality to support an application requiring encryption. decryption, signing, and verification of electronic messages. The cryptography system has a cryptographic application program interface (CAPI) which interfaces with the application to receive requests for cryptographic functions. The cryptographic system further includes at least one cryptography service provider (CSP) that is independent from, but dynamically accessible by, the CAPI. The CSP provides the cryptographic functionality and manages the secret cryptographic keys. In particular, the CSP prevents exposure of the encryption keys in a non-encrypted form to the CAPI or application. The cryptographic system also has a private application program interface (PAPI) to provide direct access between the CSP and the user. The PAPI enables the user to confirm or reject certain requested cryptographic functions, such as digitally signing the messages or exportation of keys.