In one embodiment, it is proposed a method of cryptographic processing of data, the method being executed by an electronic device, and comprising obtaining at least two points belonging to a same elliptic curve defined on an algebraic structure being a finite ring, each point being represented by at least two coordinates. The method is remarkable in that it comprises:obtaining a parameterization of an isomorphism between said elliptic curve and another elliptic curve, said parameterization defining some configuration parameters, each configuration parameter having a range of possible values;determining in function of values of coordinates of said at least two points said configuration parameters, delivering determined configuration parameters; andobtaining coordinates of another point corresponding to an image of an addition of said at least two points through said isomorphism, said another point belonging to said another elliptic curve, and said obtaining being performed without an inversion operation in said algebraic structure, due to said determined configuration parameters.