summary of digital ocean article on SSH encryption

How ssh encryption & connection works

3 types of encryption
  1. Symmetric
  2. Asymmetric (private/public keys)
  3. Hashes
 
How SSH work?
  Client-Server model
  1. Negoticate the encryption of the session (Diffie-Hellman algorithm)
  2. Authenticate the user
  
Keys are exchanged using Key exchange algorithms
Hashes are used for verifying the integrity of the messages. 

For detailed information

https://www.digitalocean.com/community/tutorials/understanding-the-ssh-encryption-and-connection-process
https://www.digitalocean.com/community/tutorials/ssh-essentials-working-with-ssh-servers-clients-and-keys#how-to-use-this-guide