Key expansion logic using decryption key primitives

A method of securely executing encrypted instructions within a microprocessor, the method comprising:

• storing a plurality of decryption key primitives in a secure memory;
• fetching encrypted instructions from an instruction cache;
• receiving two or more of the plurality of decryption key primitives from the secure memory;
• deriving a decryption key from the two or more decryption key primitives received from the secure memory;
• decrypting an encrypted instruction fetched from the instruction cache with the decryption key derived from the two or more decryption key primitives;
• and
• securely executing the decrypted instruction within the microprocessor.

A computer program product encoded in at least one non-transitory computer usable medium for use with a computing device, the computer program product comprising:

• computer usable program code embodied in said medium, for specifying a microprocessor, the computer usable program code comprising:
• first program code for specifying an instruction cache operable to store encrypted instructions;
• second program code for specifying fetch logic configured to fetch encrypted instructions from the instruction cache;
• third program code for specifying a secure memory configured to store a plurality of decryption key primitives;
• fourth program code for specifying key expansion logic configured to derive a decryption key from two or more of the plurality of decryption key primitives;
• and
• fifth program code for specifying decryption logic configured to decrypt an encrypted instruction fetched from the instruction cache with the decryption key derived from the two or more decryption key primitives.