为了便于使用Montgomery约化，专门定义了一个结构体，我们将它称作Montgomery模数，这点与Barrett模数类似。结构体的定义如下： struct bn_mont_ctx_st {         int ri;         BIGNUM RR;         BIGNUM N;         BIGNUM Ni;         BN_ULONG n0;

Montgomery约化是通过一次乘法和一个特殊的除法（除数是基数B＝232的方幂）来做模运算[9]。 M. Brown, D. Hankerson, J. Lopez and A. Menezes. Software implementation of the NIST elliptic curves over prime fields. Topics in Cryptology—CT-RSA

参考文献： [DK91] Dussé S R, Kaliski B S. A cryptographic library for the Motorola DSP56000[C]//Advances in Cryptology—EUROCRYPT’90: Workshop on the Theory and Application of Cryptographic Techniques Aarh