name short Weierstrass curves parameter a parameter b coordinate x coordinate y satisfying y^2 == x^3 + a*x + b addition x = (y2-y1)^2/(x2-x1)^2-x1-x2 addition y = (2*x1+x2)*(y2-y1)/(x2-x1)-(y2-y1)^3/(x2-x1)^3-y1 doubling x = (3*x1^2+a)^2/(2*y1)^2-x1-x1 doubling y = (2*x1+x1)*(3*x1^2+a)/(2*y1)-(3*x1^2+a)^3/(2*y1)^3-y1 negation x = x1 negation y = -y1 toweierstrass weierx = x toweierstrass weiery = y a0 = 1 a1 = 0 a2 = 0 a3 = 0 a4 = a a6 = b fromweierstrass x = weierx fromweierstrass y = weiery