An apparatus and method for performing operation being secure against side channel attack are provided. The apparatus and method generate values equal to values obtained through an exponentiation operation or a scalar multiplication operation of a point using values extracted from previously generated parameter candidate value sets and an operation secure against side-channel attack, thereby improving security against side-channel attack without degrading performance.

Apparatus and method for defending against a side-channel information attack such as a differential power analysis (DPA) attack. In some embodiments, a cryptographic hardware pipeline circuit performs a selected cryptographic function upon a selected set of data over a processing time interval. The pipeline circuit has a sequence of stages connected in series. The stages are enabled responsive to application of an asserted enable signal. An enable interrupt circuit is configured to periodically interrupt the selected cryptographic function to provide a plurality of processing intervals interspersed with the interrupt intervals. At least a selected one of the processing intervals or the interrupt intervals have random durations selected responsive to a series of random numbers.

In Elliptic Curve Cryptography (ECC), one performs a great number of modular multiplications. These are usually done by Montgomery Multiplication algorithm, which needs the operands to be preprocessed (namely, converted to the Montgomery Domain), which is normally done by an equivalent of a long division. We provide a method to perform this conversion by a single Montgomery multiplication on the raw data. The method is formulated for elliptic curve points represented in Jacobian coordinates but can be extended to other representations.

Various embodiments of the invention implement countermeasures designed to withstand attacks by potential intruders who seek partial or full retrieval of elliptic curve secrets by using known methods that exploit system vulnerabilities, including elliptic operation differentiation, dummy operation detection, lattice attacks, and first real operation detection. Various embodiments of the invention provide resistance against side-channel attacks, such as sample power analysis, caused by the detectability of scalar values from information leaked during regular operation flow that would otherwise compromise system security. In certain embodiments, system immunity is maintained by performing elliptic scalar operations that use secret-independent operation flow in a secure Elliptic Curve Cryptosystem.

Information leaked from smart cards and other tamper resistant cryptographic devices can be statistically analyzed to determine keys or other secret data. A data collection and analysis system is configured with an analog-to-digital converter connected to measure the device's consumption of electrical power, or some other property of the target device, that varies during the device's processing. As the target device performs cryptographic operations, data from the A/D converter are recorded for each cryptographic operation. The stored data are then processed using statistical analysis, yielding the entire key, or partial information about the key that can be used to accelerate a brute force search or other attack.

In Elliptic Curve Cryptography (ECC), one performs a great number of modular multiplications. These are usually done by Montgomery Multiplication algorithm, which needs the operands to be preprocessed (namely, converted to the Montgomery Domain), which is normally done by an equivalent of a long division. We provide a method to perform this conversion by a single Montgomery multiplication on the raw data. The method is formulated for elliptic curve points represented in Jacobian coordinates but can be extended to other representations.