SSL protocol was first proposed and popularized by Netscape in 1994. At that time, the network security risk became more and more serious, and people urgently needed a protocol to ensure data security to protect their information and online transactions. Netscape's SSL protocol came into being, and it was quickly applied to network devices such as servers and browsers, and was widely promoted around the world.

It is a security protocol based on TCP/IP and adopts public key technology. SSL widely supports various types of networks and provides three basic security services, all of which use public key technology.

The advantage of SSL protocol is that it is independent of application layer protocol. High-level application layer protocols (such as HTTP, FTP, Telnet, etc. ) can be transparently built on SSL protocol. SSL protocol completes encryption algorithm, communication key negotiation and server authentication before application layer protocol communication. After that, the data transmitted by the application layer protocol will be encrypted, thus ensuring the privacy of communication.

Ssl security service

1. Information confidentiality is realized by using public key and symmetric key technology. All services between SSL client and server are encrypted using the key and algorithm established during SSL handshake. This can prevent some users from using IP packet sniffing tools to eavesdrop illegally. Although packet sniffing can still capture the content of communication, it can't decipher it.

2. Information integrity to ensure the realization of all SSL business objectives. You should ensure that the information content between the server and the client will not be destroyed. SSL provides information integrity services by using secret sharing and hash function groups.

3. Two-way authentication, the process of mutual identification between the client and the server. Their identification numbers are encoded with public keys, and when SSL handshakes, their identification numbers are exchanged. In order to verify that the certificate holder is its legitimate user (not an impostor), SSL requires the certificate holder to digitally identify the exchanged data when shaking hands. The certificate holder identifies all information and data including the certificate to show that he is the legal owner of the certificate. This can prevent other users from using certificates under pseudonyms.

4.SSL security services should be as transparent as possible to end users. Usually, users can connect to SSL hosts by clicking buttons or links on the desktop. Unlike standard HTTP connection applications, the default port of a typical network host supporting SSL connection is 443, not 80.