1. An apparatus for performing an elliptic curve cryptography point addition operation using mixed affine-Jacobian coordinates comprising: a register memory for storing a first point in affine coordinates and a second point in Jacobian coordinates; a modular multiplier electrically coupled to the register memory; and a simple arithmetic processor electrically coupled to the register memory and the modular multiplier, wherein the simple arithmetic processor is configured to perform modular subtraction and modular multiplication by two in support of the point addition operation comprising a plurality of steps in mixed affine-Jacobean coordinates.