SSH Authentication

SSH provides a mechanism for establishing a cryptographically secured connection between two parties, authenticating each side to the other, and passing commands and output back and forth. SSH using numbers of encryption techniques

  • Symmetric Encryption
  • Asymmetric Encryption
  • Hashes

Symmetrical encryption is a type of encryption where one key can be used to encrypt messages to the opposite party, and also to decrypt the messages received from the other participant. This means that anyone who holds the key can encrypt and decrypt messages to anyone else holding the key.


Note: Symmetrical encryption is often called shared key or shared secret encryption

Asymmetrical encryption uses two separate keys for encryption and decryption. These two keys are known as the public key and the private key.

Asymmetrical encryption is different from symmetrical encryption in that to send data in a single direction


SSH (Secure Shell) public-key authentication relies on asymmetric cryptographic algorithms that generate a pair of separate keys (a key pair), one “private” and the other “public”.

ssh-keygen -t rsa -b 4096 -C ""