一、RSA基本原理

对明文分组M和密文分组C，加密与解密过程如下：

C = POW (M , e) mod n

M = POW(C , d) mod n = POW(POW( M ,e), d) mod n=POW( M,e*d)

其中POW是指数函数，mod是求余数函数。

其中收发双方均已知n，发送放已知e，只有接受方已知d，因此公钥加密算法的公钥为

KU={ e , n},私钥为KR={d , n}。该算法要能用做公钥加密，必须满足下列条件：

1. 可以找到e ，d和n，使得对所有M<n ,POW(M ,e*d)=M mod n .

2. 对所有 M<n,计算POW (M , e)和POW(C , d)是比较容易的。

3. 由e 和n确定d是不可行的

-one, the basic tenets of RSA expressly group M and cipher block C, encryption and decryption process is as follows : C = POW (M, e) mod n = M POW (C, d) mod n = POW (POW (M, e), d) mod n = POW (M, e * d), which is an exponential function POW, mod is the pursuit of the remaining functions. Transceivers which both known n, send e Fang known, the only known recipient d, therefore the public key encryption algorithm for public key e KU = (n), private key for KR = (d, n). The algorithm could be used to be a public key encryption, must meet the following conditions : 1. E can be found, and d n, making all the right M