Cryptographic operation performing procedure for chip card, involves hiding specific number by definite times of random number before doing division and/or modular reduction and subtracting random number from division result

摘要

The procedure involves hiding a number (a) by (b) times of a random number (p) before performing entire division and/or modular reduction. Contribution made by the random number is removed from a result of the entire division after performing the entire division. The random number is subtracted from the result of the entire division during which the contribution is deducted from the result. An Independent claim is also included for a chip card comprising an electronic component for implementing a cryptographic procedure.