crypto/bn/stuff/mont.doc - third_party/openssl - Git at Google

 All numbers (a) are stored aR mod N (except abRR)

 RR = REDC(R*R)	/* RR mod N */


 convert a -> aR
 convert b -> bR

 	{
 	abRR = aR * bR
 	abR = REDC(abRR); /* mod N */
 	}

 ab = REDC(abR);   /* mod N */


 REDC strips off a multiplicaion by R mod N
	All numbers (a) are stored aR mod N (except abRR)

	RR = REDC(RR) / RR mod N */


	convert a -> aR
	convert b -> bR

	{
	abRR = aR * bR
	abR = REDC(abRR); /* mod N */
	}

	ab = REDC(abR); /* mod N */


	REDC strips off a multiplicaion by R mod N