hash and mac algorithms are used for the confidentiality and integration of data sent over the network by sender to the receiver.

关于PKI(公钥基础设施)的介绍，CA的介绍，CA如何管理证书，以及证书在网络中的使用。对于了解CA,证书有一定的帮助-About the introduction of the PKI (public key infrastructure), the introduction of CA, CA How management certificate, as well as the use of the certificate in the network. Understanding the

一份关于信息内容安全的源代码，可以较好地保护信息内容的安全-A report on the information content security source code, can be used to protect the security of information content

this about GCD function -this is about GCD function