Patent ID: 11552796

Abstract:
A cryptographic method is provided. The cryptographic method comprises an initialisation phase for determining a provisional generator point G′ equal to a first product G′=[d′]G, where d′ is a first random scalar forming a secret key of N bits and G is a generator point of an elliptical curve, and determining a provisional key Q′ equal to a second product Q′=[d′]Q, where Q is a point of the elliptical curve forming a public key. During an encryption phase a second random scalar forming a second secret key k of M bits, with M<N; a public key P is calculated such that P=[k]G′; a coordinate of an intermediate point SP1, of the elliptical curve, equal to a fourth product SP1=[k]Q′; at least one key by application of a derivation function (F1); and data (T1) are encrypted based on said at least one key.