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OpenSSH

(also Open Secure Shell)

OpenSSH definition

OpenSSH is a suite of utilities based on the Secure Shell protocol, facilitating secure remote login and network services. It encrypts communication over networks, replacing insecure protocols like telnet, and includes features like cryptographic host key verification.

See also: secure shell

History of OpenSSH

OpenSSH emerged in 1999 from the OpenBSD project as a free alternative to the proprietary Secure Shell software created by Tatu Ylönen. Theo de Raadt and his team developed it as a fork of the last free SSH version, focusing on enhanced security and removing proprietary elements.

Quickly adopted by the open-source community, OpenSSH became the default SSH implementation for many Linux and Unix systems. Continually evolving, it added secure file transfer protocols like SCP and SFTP.

Use cases of OpenSSH

  • Secure remote server administration. OpenSSH allows system administrators to securely access and manage servers remotely over unsecured networks. It encrypts all traffic, including passwords, to prevent interception and unauthorized access.
  • Secure file transfers. OpenSSH provides tools like SCP (Secure Copy) and SFTP (SSH File Transfer Protocol) for encrypting file transfers between systems.
  • Creating secure tunnels and port forwarding. OpenSSH can establish secure SSH tunnels for forwarding network ports and encrypting network traffic.