SSH (Secure Shell)
SSH (Secure Shell) is a network protocol used to securely connect to remote machines over an unsecured network. It encrypts the connection and provides various mechanisms for authentication and data transfer.
SSH has two versions: SSH-1 and SSH-2. SSH-2 was standardized by the IETF.
It has three main layers: Transport Layer, Authentication Layer, and Connection Layer.
- Transport Layer
The Transport Layer provides encryption, integrity, and data protection to ensure secure communication between the client and server. - Authentication Layer
The Authentication Layer verifies the identity of the client to ensure that only authorized users can access the server. - Connection Layer
The Connection Layer multiplexes the encrypted and authenticated communication into multiple logical channels.