International Business Machines Corporation

Leonard L Fogell

Chin-Long Chen

Vincenzo Condorelli

Edward W Chencinski

Arnold Weinberger

Samir Kirit Patel

Samuel R Levine

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 to circuits and methods for carrying out modular exponentiation.

Circuits and methods for modular exponentiation

This error checker determines if more than one set of control signals F1 through FN are on and also flags invalid as opposed to valid situations where none of the control signals F1 to FN are on. To distinguish the invalid from valid situations where none of the control signals F1 to FN are on, an additional control signal X=F1.multidot.F2.multidot. . . . .multidot.FN is generated and then fed with the control signals F1 to FN through a prior art detector which detects when more than one or none of the control signals X and F1 through FN are on.

Error checking of mutually-exclusive control signals

Growing community of inventors

Hyde Park, NY, United States of America

Leonard L Fogell