The SSH(Secure Shell) is an access credential that is used in the SSH Protocol. It is a cryptographic network protocol used for transferring encrypted data over the network.

SSH keys always comes in pairs:

Public Key - Everyone can see it. For encryption.

Private key - Stays in the computer. For decryption.

Key pair types:

User key - If the key pairs remain with the user.

Host key - If key pairs are on a remote system.

Session key - Used when a large amount of data is to be transmitted.

SSH Features

SSH can…

• Provide high security
• Provide confidentiality
• Allow remote login
• Provide a secure File Transfer Protocol
• Support tunneling which provides more secure connection communication

SSH Protocol

Techniques used in SSH

Symmetric Cryptography: The same key is used for encryption and decryption. A unique single key is kept between the sender and receiver.

Asymmetric Cryptography: Two different keys are used for encryption and decryption.

Hashing: Hashing encrypts strings using a hash function which results in a string that may seem like gibberish called the hash value.