Merge branch 'undefined' into '2-attach-and-verify-sage-files-in-cryptocore'

Pointdoubling_affine

See merge request !4

ECC Over GF(2m)/sage/Pointdoubling_affine.sage

+def Pointdoubling_affine(x1,y1,a,n,PRECISION):
+
+
+     x1_poly = str_to_poly(x1)
+     y1_poly = str_to_poly(y1)
+ 
+     #print 'x1_poly =', x1_poly
+     #print 'y1_poly =', y1_poly
+
+     xpoly = (1)
+     expp = 2^PRECISION-2
+     for i in reversed(xrange(PRECISION)):
+	                  xpoly = xpoly * xpoly
+	                  if(expp.digits(base = 2,padto=PRECISION)[i] == 1):
+					   xpoly = y1_poly* xpoly
+     inv_y1_poly = xpoly
+
+     s_poly = (3*x1_poly*x1_poly+a)*2*inv_y1_poly
+
+     x2_poly = s_poly*s_poly-2*x1_poly
+
+     y2_poly = s_poly*(x1_poly-x2_poly)-y1_poly
+
+     print 'x2 =',poly_to_str(x2_poly)
+     print 'y2 =',poly_to_str(y2_poly)
+