公开(公告)号：US20130163751A1

公开(公告)日：2013-06-27

申请号：US13723552

申请日：2012-12-21

Applicant: OBERTHUR TECHNOLOGIES

Inventor： Emmanuelle Dottax ,  Sebastien Aumonier

IPC: H04L9/28

CPC classification number: H04L9/28 ,  G06F7/725 ,  H04L9/3066

Abstract: A method and apparatus are proposed for cryptographic computations implemented in an electronic component. The method includes determining the cofactor of an elliptic curve E defined over a finite field Fq with q elements, the elliptic curve comprising a base point P having an order equal to n. The step of determining includes determining a value of floor((q+2ceil(b/2)+1+1)/n) when n>6√q, where the function ceil corresponds to the ceiling function, floor corresponds to the floor function, and b corresponds to the size q in number of bits of q.

Abstract translation: 提出了一种用于在电子部件中实现的密码计算的方法和装置。 该方法包括确定在具有q个元素的有限域Fq上定义的椭圆曲线E的辅因子，该椭圆曲线包括具有等于n的阶数的基点P. 确定步骤包括当n>6√q时确定floor（（q + 2ceil（b / 2）+ 1 + 1）/ n）的值，其中功能ceil对应于天花板功能，floor对应于floor 函数，b对应于q的位数q。