Abstract: The present invention provides a method for protecting public key schemes from timing, power and fault attacks. In general, this is accomplished by implementing critical operations using “branchless” or fixed execution path routines whereby the execution path does not vary in any manner that can reveal new information about the secret key during subsequent operations. More particularly, the present invention provides a modular exponentiation algorithm without any redundant computation so that it can protect the secret key from C safe error attacks. The improved method also provides an algorithm that doesn't have a store operation with non-certain destination so that the secret key is immune from M safe error attacks.

Abstract: A direction adjustable device includes a motor drive unit for driving a turnable unit to turn, and a sensor assembly which includes a force transmitting member, a cable having first and second ends connected to the force transmitting member and a steering linkage, respectively, a rotary control switch coupled to the force transmitting member such that pivoting movement of the latter is transmitted to a signal processing unit, and a reversing member adapted to be connected to the steering linkage.

Abstract: An apparatus for encryption and decryption, capable of use in encryption and decryption of advanced encryption standard. Byte substitution operation and inverse byte substitution operation are to be combined. Byte substitution operation can be expressed as y=M*multiplicative_inverse(x)+c while inverse byte substitution operation can be expressed as x=multiplicative_inverse(M−1*(y+c)), wherein M and M−1 are inverse matrix of each other and c is a constant matrix. Since the two equations employ a look-up table, that is, multiplicative_inverse(x), the lookup tables for use in byte substitution and inverse byte substitution operations are to be combined according to the invention so as to lower hardware complexity of the implementation. In addition, main operations of column mixing operation and inverse column mixing operation are to be rearranged to combine the two operations in part, resulting in simplified hardware implementation.

Abstract: There is disclosed a high-performance Booth-encoded Montgomery module for performing the computation of A*B*r−1 (mod N). A Booth encoder is provided for receiving two bits of A to perform a Booth encoding process, so as to produce a Booth code. A multiplicand selector is provided for receiving B and the Booth code so as to select a multiplicand. A first carry propagate adder is provided for adding the output of the multiplicand selector and a previous computation result to output. A multiplexer is provided for receiving four inputs 0, N, 2N, and 3N from a lookup table and selecting one of the inputs to output. A second carry propagate adder is provided for adding the outputs of the first carry propagate adder and the multiplexer to output. A shifter is provided for shifting the output from the second carry propagate adder to right by two bits, so as to produce a computation result.

Abstract: An electronic tape rule comprising a housing, in which reside a steel tape that can be extended from the housing, a reading system that measures the extent of tape extension, and a sound play circuit that gives a read-out of the result of measurement. When the steel tape is extended from the housing, the reading system measures the extent of tape extension and passes this information to the sound play circuit to report the result of measurement for the convenience of users, especially when the measurement is operated in a dark environment.

Abstract: An automobile includes an automobile body, a wheel drive assembly mounted to the automobile body, a front lamp device mounted turnably on the automobile body, a motor drive device coupled to the front lamp device and operable so as to turn the front lamp device relative to the automobile body, and a control device coupled electrically to the motor drive device and coupled mechanically to the wheel drive assembly for detecting angular rotation of a steering wheel of the wheel drive assembly and for operating the motor drive device so as to turn the front lamp device by an angle corresponding to the angular rotation of the steering wheel.