Abstract: A data security system and method for providing a cryptographic process such as the Data Encryption Standard comprises a microprocessor having a programmable hardware element such as a field programmable gate array interfaced to the processor bus. The predetermined ordered sequence of operations which form the cryptographic process are parsed into hardware-centric operations such as bit manipulations, table look-ups and logic operations which are efficiently performed in hardware, and into software-centric operations such as data processing and state machine control. Hardware-centric operations are performed in the programmable hardware device, and overall control of the system is performed under microprocessor control.