Patent ID: 9450755
Filing Date: 2016-09-20
CPC Classification: H04L

Claim Text:
1. Method for operating a transponder, the method comprising: receiving transmitted reader data by the transponder, the reader data comprising a representation of x a representation of sqrt[b]/x, redundant information associated with x, and redundant information associated with sqrt[b]/x, wherein x is an element of a binary Galois field and b is a constant; determining, by the transponder, whether x is a first coordinate of a point on an elliptic curve defined by the elliptic curve equation y calculating a product from the redundant information associated with x and the redundant information associated with sqrt[b]/x; and determining if redundant information in the calculated product is known by the transponder; wherein the elliptic curve is defined over the Galois field such that x and y are elements of the Galois field, wherein y is a second coordinate of the point on the elliptic curve.