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Invention

Secure Shell

Software Engineering

Secure Shell, or SSH, is a cryptographic network protocol that lets a user log into and run commands on a remote computer over an unsecured network while encrypting the entire session. Finnish researcher Tatu Ylönen created SSH in 1995 at the Helsinki University of Technology after a password-sniffing attack on his university's network, releasing it as a safer replacement for the older, unencrypted Telnet and rlogin tools. SSH became the standard method system administrators use to manage remote servers securely, and it is also commonly used to tunnel other kinds of network traffic through an encrypted connection.

Facts
Year
1995 1
Significance
A cryptographic network protocol for securely operating network services, chiefly remote login and command-line execution, over an unsecured network. 1
FAQs

Which network port does Secure Shell use?

Port 22 over TCP/IP.

When it runs over TCP/IP, an SSH server normally listens for connections on port 22. That port number is registered with the Internet Assigned Numbers Authority (IANA) and officially assigned for SSH, so clients and firewall rules can rely on it as the standard address for the service.

What security protections does the SSH transport layer provide?

Server authentication; confidentiality and integrity; optional compression.

The transport layer protocol of SSH provides server authentication, confidentiality and integrity, and it may optionally also provide compression. It is typically run over a TCP/IP connection, though the specification allows it to sit on top of any other reliable data stream.
Connections

In Field

Source Wikipedia: Secure Shell
Sources
1. Wikipedia: Secure Shell
  • Lead section, sixth sentence
    Finnish computer scientist Tatu Ylönen designed SSH in 1995 and provided an implementation in the form of two commands, ssh and slogin, as secure replacements for rsh and rlogin, respectively.
  • Lead section, first sentence
    The Secure Shell Protocol (SSH Protocol) is a cryptographic network protocol for operating network services securely over an unsecured network.
  • In Group: Internet Communication Protocols, lead sentence: a cryptographic network protocol for operating network services securely over an unsecured network
  • In Field: Software Engineering, Lead section
    The Secure Shell Protocol (SSH Protocol) is a cryptographic network protocol for operating network services securely over an unsecured network.
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