RSA算法是第一个能同时用于加密和数字签名的算法，也易于理解和操作。RSA是被研究得最广泛的公钥算法，从提出到现在已近二十年，经历了各种攻击的考验，逐渐为人们接受，普遍认为是目前最优秀的公钥方案之一(The RSA algorithm is the first algorithm that can be used for both encryption and digital signature at the same time. It is also easy to understand and operate. RSA is the most widely researched public key algorithm. It has been nearly twenty years since it was put forward. It has been tested by various kinds of attacks and gradually accepted by people. It is generally considered to be one of the best public key schemes at present. The security of RSA depends on the factor decomposition of large numbers, but it does not theoretically prove that the difficulty of breaking the RSA is equivalent to the difficulty of the large number decomposition.)