Behavioral fingerprint in a white-box implementation

A method of producing a cryptographic implementation of a cryptographic operation mapping an input message to an output message in a cryptographic system that determines a fingerprint identification of the cryptographic implementation, comprising:

• producing a cryptographic implementation of the keyed cryptographic operation;
• receiving information specifying at least one fingerprint message and a user specific value;
• modifying the cryptographic implementation based upon the received information specifying a fingerprint message and a user specific value so that:
• when a received input message is one of the fingerprint messages, the cryptographic implementation outputs an output message based upon the user specific value;
• and
• when a received input message is not one of the fingerprint messages, the cryptographic implementation outputs an output message associated with the received input message based upon the cryptographic operation.

A non-transitory machine-readable storage medium encoded with instructions for execution by a cryptographic implementation in a cryptographic system for determining a fingerprint identification, the non-transitory machine-readable storage medium comprising:

• instructions for receiving, by the cryptographic system, an input message that is a fingerprint identification message;
• instructions for performing, by the cryptographic system, a keyed cryptographic operation mapping the fingerprint identification message into an output message that includes a fingerprint identification;
• and
• instructions for outputting the output message.