"SSH" redirects here. For other uses, see SSH (disambiguation).
Secure Shell
Protocol stack
Purpose
secure connection, remote access
Developer(s)
Tatu Ylönen, Internet Engineering Task Force (IETF)
Introduction
1995
OSI layer
Transport layer through application layer
Port(s)
22
RFC(s)
RFC 4250, RFC 4251, RFC 4252, RFC 4253, RFC 4254
Internet protocol suite
Application layer
BGP
DHCP (v6)
DNS
FTP
HTTP (HTTP/3)
HTTPS
IMAP
IRC
LDAP
MGCP
MQTT
NNTP
NTP
OSPF
POP
PTP
ONC/RPC
RTP
RTSP
RIP
SIP
SMTP
SNMP
SSH
Telnet
TLS/SSL
XMPP
more...
Transport layer
TCP
UDP
DCCP
SCTP
RSVP
QUIC
more...
Internet layer
IP
v4
v6
ICMP (v6)
NDP
ECN
IGMP
IPsec
more...
Link layer
ARP
Tunnels
PPP
MAC
more...
v
t
e
The Secure Shell Protocol (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network.[1] Its most notable applications are remote login and command-line execution.
SSH was designed on Unix-like operating systems, as a replacement for Telnet and for unsecured remote Unix shell protocols, such as the Berkeley Remote Shell (rsh) and the related rlogin and rexec protocols, which all use insecure, plaintext methods of authentication, like passwords.
Since mechanisms like Telnet and Remote Shell are designed to access and operate remote computers, sending the authentication tokens (e.g. username and password) for this access to these computers across a public network in an unsecured way, poses a great risk of 3rd parties obtaining the password and achieving the same level of access to the remote system as the telnet user. Secure Shell mitigates this risk through the use of encryption mechanisms that are intended to hide the contents of the transmission from an observer, even if the observer has access to the entire data stream.[2]
SSH was first designed in 1995 by Finnish computer scientist Tatu Ylönen (to replace the Telnet network protocol). Subsequent development of the protocol suite proceeded in several developer groups, producing several variants of implementation. The protocol specification distinguishes two major versions, referred to as SSH-1 and SSH-2. The most commonly implemented software stack is OpenSSH, released in 1999 as open-source software by the OpenBSD developers. Implementations are distributed for all types of operating systems in common use, including embedded systems.
SSH applications are based on a client–server architecture, connecting an SSH client instance with an SSH server.[3] SSH operates as a layered protocol suite comprising three principal hierarchical components: the transport layer provides server authentication, confidentiality, and integrity; the user authentication protocol validates the user to the server; and the connection protocol multiplexes the encrypted tunnel into multiple logical communication channels.[1]
^ abT. Ylonen; C. Lonvick (January 2006). The Secure Shell (SSH) Protocol Architecture. IETF Trust. doi:10.17487/RFC4251. RFC 4251.
^"Missouri University S&T: Secure Telnet".
^T. Ylonen; C. Lonvick (January 2006). The Secure Shell (SSH) Authentication Protocol. IETF Trust. doi:10.17487/RFC4252. RFC 4252.
The SecureShell Protocol (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable...
unencrypted passwords over the network. rsh has largely been replaced with the secureshell (ssh) program, even on local networks. As an example of rsh use, the...
port 4789): Virtual Extensible Local Area Network. GENEVE WireGuard A SecureShell (SSH) tunnel consists of an encrypted tunnel created through an SSH protocol...
between two remote hosts. It is based on the SecureShell (SSH) protocol. "SCP" commonly refers to both the Secure Copy Protocol and the program itself. According...
confused with the SSH File Transfer Protocol (SFTP), a secure file transfer subsystem for the SecureShell (SSH) protocol with which it is not compatible. It...
known as OpenBSD SecureShell) is a suite of secure networking utilities based on the SecureShell (SSH) protocol, which provides a secure channel over an...
operation via serial hardware connections or SecureShell are common for server systems. All Unix shells provide filename wildcarding, piping, here documents...
Look up shell in Wiktionary, the free dictionary. Shell may refer to: Shell (structure), a thin structure Concrete shell, a thin shell of concrete, usually...
over any reliable data stream that was designed as an extension of the SecureShell protocol (SSH) version 2.0. The current implementation of SSHFS using...
specifically developed by the IETF to run over secureshell connections FTP over SSH, also known as "secure FTP" — the practice of using SSH to tunnel the...
another server, i.e. forward data securely from another client application running on the same computer as a SecureShell (SSH) client. By using local port...
proprietary secure remote access software developed for Windows and available as a client and server. The software is based on the SecureShell (SSH) protocol...
remote shells such as a Remote Shell (rsh) a SecureShell (ssh) are really just tools to run a more complex shell on a remote system and have no 'shell' like...
A SecureShell fingerprint record (abbreviated as SSHFP record) is a type of resource record in the Domain Name System (DNS) which identifies SSH keys...
Barrett, Daniel; Silverman, Richard; Byrnes, Robert (2005). SSH, The SecureShell: The Definitive Guide. O'Reilly Media. pp. 577–579. ISBN 9780596008956...
multi-factor authentication. SecureShell (SSH) is a client-server protocol that uses public-key cryptography to create a secure channel over the network...
Examples of firmware that implement the specification are AMI Aptio, Phoenix SecureCore, TianoCore EDK II, InsydeH2O. UEFI replaces the BIOS which was present...
the job, e.g. SSH File Transfer Protocol or Secure Copy Protocol. Using a secure tunnel such as SecureShell (SSH) or virtual private network (VPN). FTP...
Engineering Task Force (IETF) as an extension of the SecureShell protocol (SSH) version 2.0 to provide secure file transfer capabilities, and is seen as a replacement...
Protocol a file transfer protocol secured by the SecureShell (SSH) protocol Secure copy (scp) is based on the SecureShell (SSH) protocol HTTP can support...
An SSH client is a software program which uses the secureshell protocol to connect to a remote computer. This article compares a selection of notable...
the SSH File Transfer Protocol (SFTP), which runs inside the encrypted SecureShell connection. It provides an interactive interface similar to that of traditional...
"SSH: SecureShell § History of the SSH Protocol". SSH.com. Retrieved 3 March 2018. Rescorla, Eric; Schiffman, Allan M. (August 1999). The Secure HyperText...
curve25519-dalek Bouncy Castle OMEMO, a proposed extension for XMPP (Jabber) SecureShell Signal Protocol Matrix (protocol) Tox Zcash Transport Layer Security...
Global Information