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Secure Shell

Secure Shell definition

Secure Shell (SSH) refers to a cryptographic network protocol used in secure communication between devices. SSH encrypts data using cryptographic algorithms, such as Advanced Encryption System (AES) and is often used when logging in remotely to a computer or server.

See also: SFTP server, Port knocking

How Secure Shell works

Secure Shell works as a multi-layer protocol that consists of three components:

  • The transport layer. It secures data in transit and ensures data integrity.
  • User authentication. It protects the user’s connection to the server.
  • The connection protocol. It establishes a secure connection between two networks.

Secure shell examples

  • Remote login. Administrators commonly use SSH for remote logins to a server or a device on a network, such as a router.
  • File transfer. SSH protocol can be used to transfer files securely between two devices on the network.
  • Tunneling. SSH can be used to create a secure tunnel between two networked devices, allowing traffic to pass between them securely.
  • Port forwarding. Since port forwarding is used to provide access to a server or application on a remote device, SSH is used to forward network traffic securely.
  • Security. SSH can be used to secure file transfer protocols.