The modular exponentiation function used in public key encryption and decryption
systems is implemented in a standalone engine having at its core modular multiplication
circuits which operate in two phases which share overlapping hardware structures.
The partitioning of large arrays in the hardware structure, for multiplication
and addition, into smaller structures results in a multiplier design comprising
a series of nearly identical processing elements linked together in a chained fashion.
As a result of the two-phase operation and the chaining together of partitioned
processing elements, the overall structure is operable in a pipelined fashion to
improve throughput and speed. The chained processing elements are constructed so
as to provide a partitionable chain with separate parts for processing factors
of the modulus. In this mode, the system is particularly useful for exploiting
characteristics of the Chinese Remainder Theorem to perform rapid exponentiation
operations. A checksum mechanism is also provided to insure accurate operation
without impacting speed and without significantly increasing complexity. While
the present disclosure is directed to a complex system which includes a number
of features, the present application is particularly directed a system and method
for performing modular checksum operations.
