Understand SHell Security: SSH and OpenSSH

The Security SHell (or SSH ) is a remote access tool widely used in Unix systems. Sitema its implementation in GNU / Linux is called OpenSSH.

OpenSSH is not the only option available for remote access NIX systems, we can mention others such as telnet, rlogin, rcp etc., but only the OpenSSH works safely, the key systems using public key private key x of variable size and can be either RSA or DSA