Abstract: Disclosed is a method for detecting clock tampering. In the method a plurality of resettable delay line segments are provided. Resettable delay line segments between a resettable delay line segment associated with a minimum delay time and a resettable delay line segment associated with a maximum delay time are each associated with discretely increasing delay times. A monotone signal is provided during a clock evaluate time period associated with a clock. The monotone signal is delayed using each of the plurality of resettable delay line segments to generate a respective plurality of delayed monotone signals. The clock is used to trigger an evaluate circuit that uses the plurality of delayed monotone signals to detect a clock fault.

Abstract: Disclosed is a method for detecting clock tampering. In the method a plurality of resettable delay line segments are provided. Resettable delay line segments between a resettable delay line segment associated with a minimum delay time and a resettable delay line segment associated with a maximum delay time are each associated with discretely increasing delay times. A monotone signal is provided during a clock evaluate time period associated with a clock. The monotone signal is delayed using each of the plurality of resettable delay line segments to generate a respective plurality of delayed monotone signals. The clock is used to trigger an evaluate circuit that uses the plurality of delayed monotone signals to detect a clock fault.

Abstract: A computationally efficient multiplication method and apparatus for modular exponentiation. The apparatus uses a preload register, coupled to a multiplier at a second input port via a KN bit bus to load the value of the “a” multiplicand in the multiplier in a single clock pulse. The “b” multiplicand (which is also KN bits long) is supplied to the multiplier N bits at a time from a memory output port via an N bit bus coupled to a multiplier first input port. The multiplier multiplies the N bits of the “b” multiplicand by the KN bits of the “a” multiplicand and provides that product at a multiplier output N bits at a time, where it can be supplied to the memory via a memory input port.

Abstract: A computationally efficient multiplication method and apparatus for modular exponentiation. The apparatus uses a preload register, coupled to a multiplier at a second input port via a KN bit bus to load the value of the “a” multiplicand in the multiplier in a single clock pulse. The “b” multiplicand (which is also KN bits long) is supplied to the multiplier N bits at a time from a memory output port via an N bit bus coupled to a multiplier first input port. The multiplier multiplies the N bits of the “b” multiplicand by the KN bits of the “a” multiplicand and provides that product at a multiplier output N bits at a time, where it can be supplied to the memory via a memory input port.

Abstract: A receiving system for aligning a first signal to a reference signal is disclosed. In the receiving system, a selectable delay receives a first signal and delays the first signal by a selectable amount to generate a delayed first signal. A phase detector receives the delayed first signal and a reference signal and generates phase information which represents a phase difference between the delayed first signal and the reference signal. A phase accumulator receives and accumulates the phase information and generates delay select information which represents an accumulated phase difference between the delayed first signal and the reference signal. The selectable delay receives the delay select information and delays the first signal based on the delay select information, resulting in improved alignment of the delayed first signal and the reference signal. The receiving system may also include a second delay for receiving a second signal and delaying it by a fixed amount to generate the reference signal.

Abstract: A computationally efficient multiplication method and apparatus for modular exponentiation. The apparatus uses a preload register, coupled to a multiplier at a second input port via a KN bit bus to load the value of the “a” multiplicand in the multiplier in a single clock pulse. The “b” multiplicand (which is also KN bits long) is supplied to the multiplier N bits at a time from a memory output port via an N bit bus coupled to a multiplier first input port. The multiplier multiplies the N bits of the “b” multiplicand by the KN bits of the “a” multiplicand and provides that product at a multiplier output N bits at a time, where it can be supplied to the memory via a memory input port.

Abstract: A method and apparatus for performing high-speed computation of a Montgomery value defined as 22k mod(n) for an arbitrary modulus n is disclosed. After loading the value of 2(h*m)+1 into a first register and the value of the modulus n in a second register, the bits of modulus n are shifted in a most significant bit direction before a repeated modular reduction and squaring process. This allows the computation of the Montgomery value for modulus values of arbitrary sizes while reducing the number of computations required by a processor with a limited operand size.