| When network has been born at the beginning of the birth, the information security network is a difficult problem which always troubles network's builders and users. With the increasing popularity of network applications and the development of new network technology, the information security network has become an increasingly critical issue in the network society and the focus of network research. It has been researched in the field of the principles set of scientific determination of network risks, security and safety technology means, and seen the principles establishing and implementation methods of the network information safety protection as a complete system. The basic thought of the network information safety protection which has been proposed is also derived from practice but higher than practice, which have instructive significance to protection of network information security practices.Network security is a perpetual issue. There are more or less computer security problems on the Internet, if they aren't being taken seriously, they will inevitably lead to serious consequences. The system has been damaged, data loss, theft of confidentiality and direct, indirect economic losses, all of these are undeniable problems. As to the network security, we are used to employing firewall, antivirus software, etc. These are indeed important, but people often overlook the most important-ideology. Transport Layer Security (TLS) and its predecessor-Secure Sockets Layer (SSL), are available on the Internet which offer secure encrypted communication protocol. TLS and SSL encrypted network connection over the transport layer, using symmetric encryption and the reliability of a key message of the message authentication code respectively.TLS has a variety of security measures, protection which against a downgrade of the protocol to a previous (less secure) version or a weaker cipher suite. Numbering subsequent Application records with a sequence number and using this sequence number in the message authentication codes (MACs). Using a message digest enhanced with a key (so only a key-holder can check the MAC). The HMAC construction, which used by most TLS cipher suites is specified in RFC 2104 (SSL 3.0 'used a different hash-based MAC). The message that ends the handshake sends a hash of all the exchanged handshake messages seen by both parties. The pseudorandom function splits the input data in half and processes each one with a different hashing algorithm (MD5 and SHA-1), then XOR them together to create the MAC. This provides protection even if one of these algorithms is found to be vulnerable. |
