1. An apparatus for performing cryptographic operations, comprising: a cryptographic instruction, received by a computing device as part of an instruction flow executing on said computing device, wherein said cryptographic instruction prescribes one of the cryptographic operations, and wherein said cryptographic instruction prescribes one of a plurality of cryptographic key sizes; and execution logic, operatively coupled to said cryptographic instruction, configured to execute said one of the cryptographic operations, said execution logic comprising: a key size controller, configured to employ said one of a plurality of cryptographic key sizes during execution of said one of the cryptographic operations.