Secure Shell has seen steady improvement and increased adoption since 1995. The first
version of Secure Shell (SSH1) was designed to replace the non-secure UNIX “rcommands”
(rlogin, rsh, and rcp). Secure Shell version 2 (SSH2), submitted as an
Internet Engineering Task Force (IETF) draft in 1997, addresses some of the more
serious vulnerabilities in SSH1 and also provides an improved file transfer solution.