Patent ID: 8379842
Filing Date: 2013-02-19
Classification: G06F,H04L

Abstract:
1. A cryptographic method for a cryptographic system, the method comprising: receiving a basic point P on an elliptic curve and a scalar k; initializing a plurality of primary variables with the basic point P; iterating through a plurality of operations using a repetitive operation variable i, where i is an integer; wherein the plurality of operations includes: identifying a fault, in one or more of setting the plurality of secondary variables, resetting the plurality of primary variables and secondary variables, and calculating the scalar product Q, the identifying of the fault using the plurality of primary variables and secondary variables based on the portion of the scalar k, the fault identified by one of determining that values of at least two of the secondary variables are different and determining that at least one of the secondary variables is different from at least one of the primary variables; and outputting the scalar product Q if there is no fault identified; wherein initializing the plurality of primary variables includes: wherein the plurality of secondary variables includes a first secondary variable T if the binary bit k if the binary bit k