System and method for performing cryptographic operations include providing at least one processor for performing cryptographic operations, memory coupled to the processor for use in performing the cryptographic operations; and a storage component coupled to the processor for storing and retrieving information calculated and used in the cryptographic operations. The processor, memory and storage component are securely enclosed whereby direct access to the cryptographic operations is prevented. A first power source, which is external to the secure enclosure, is coupled to and supplies power to the processor, the memory and the storage component. A second power source, which is internal to the secure enclosure, is coupled to and supplies power to at least the processor. A switch is included for switching from the first power source to the second power source when the cryptographic operations are being performed and for switching from the second power source to the first power source when non-cryptographic operations are being performed.