Patent ID: 8627105

Claim:
A programmable integrated circuit device comprising: an input for configuration data for said programmable integrated circuit device, wherein said programmable integrated circuit device is partially reconfigurable by writing an original portion of configuration data into said input and subsequently writing an additional portion of configuration data into said input, said original portion of configuration data being at least partially encrypted according to a first encryption scheme, and said additional portion of configuration data being at least partially encrypted according to a second encryption scheme; a plurality of key stores that store a plurality of respective keys for at least said first and second encryption schemes; control circuitry operable to identify required keys from said at least partially encrypted original portion of configuration data and said at least partially encrypted additional portion of configuration data, and operable to generate respective key selection signals; and key selection circuitry responsive to said respective key selection signals, and operable to read said plurality of key stores and to provide said required keys to said control circuitry; wherein: said control circuitry includes decryption circuitry operable to decrypt said at least partially encrypted original configuration data and said at least partially encrypted additional portion of configuration data using respective ones of said required keys.