SSH (Secure Shell layer)

SSH is the abbreviation for secure Shell, which is developed by the IETF Network Working Group, andSSH is a security protocol based on the application layer . SSH is currently a more reliable protocol that provides security for Telnet sessions and other network services. The use of SSH protocol can effectively prevent the information leakage in the remote management process. SSH was originally a program on a UNIX system, and later expanded quickly to other operating platforms. SSH can compensate for vulnerabilities in the network when it is used correctly. The SSH client is available on a variety of platforms. Almost all UNIX platforms-including HP-UX, Linux, AIX, Solaris, Digital UNIX, Irix, and other platforms-can run SSH.

SSH has many features that can replace Telent,ftp,pop and even provide a secure channel for PPP.

SSH is made up of client and server Software , and there are two incompatible versions: 1.x and 2.x respectively. SSH 2.x client program is not connected to the SSH 1.x service program up. The OpenSSH 2.x also supports SSH 1.x and 2.x.

The server is a daemon (daemon) that runs in the background and responds to connection requests from the client. The server is usually the sshd process, which provides the processing of the remote connection, generally including public key authentication, key exchange, symmetric key encryption and non-secure connection. The client includes SSH programs and other applications such as SCP (remote copy), slogin (remote login), SFTP (Secure file transfer), etc.

SSH (Secure Shell layer)