MD5 (Message-Digest algorithm 5) is a widely used, partially insecure[1] cryptographic hash function with a 128-bit hash value. As an Internet standard (RFC 1321), MD5 has been employed in a wide variety of security applications, and is also commonly

MD5的全称是Message-digest Algorithm 5（信息-摘要算法），在90年代初由MIT Laboratory for Computer Science和RSA Data Security Inc,的Ronald L. Rivest开发出来，经MD2、MD3和MD4发展而来。它的作用是让大容量信息在用数字签名软件签署私人密钥前被\"压缩\"成一种保密的格式（就是把一个任意长度的字节串变换成一定长的大整数）。不管是MD2、MD4还是MD5，它们都需要获得一个随机长度的信息并产生一

RFC 3261，中英文都有，学习和研究SIP的同志是大有帮助的-RFC 3261, both in English and Chinese, learning and research comrades SIP is a great help

The MD5 message-digest algorithm is a widely used cryptographic hash function that produces a 128-bit (16-byte) hash value. Specified in RFC 1321, MD5 has been utilized in a wide variety of security applications, and is also commonly used to check da