It is an object of the invention to provide a processor that combines finite field arithmetic and integer arithmetic for providing operations required for Elliptic Curve (EC) cryptography. It is a further object of the invention to provide an arithmetic processor design that may be scaled to different field or register sizes. A still further object of the invention to provide an arithmetic processor that may be used with different field sizes. A stil further object of the invention to provide an arithmetic processor that is capable of being scaled to provide an increase in spead when performing multi-sequence operations by simultaneously executing multiple steps in the sequence.