Passwordless Secure Socket Shell (Passwordless SSH)
Passwordless SSH means the SSH client connecting to the SSH server does not need to present the account password in order to establish the connection. Instead, the client uses an asymmetric cryptographic key pair (private key on the client) to authenticate.
Passwords are considered vulnerable because they are easy to steal and in many cases also easy to break. Passwordless authentication, when implemented properly using sound cryptography or other means, can provide a higher security for authentication.
Passwordless authentication is any authentication scheme that does not rely on the user having to recall a string (a password) that is used as a shared secret between two parties. Passwordless authentication could therefore be implemented in any number of ways. Common ways to implement it include cryptography and biometrics.
Removing vulnerable passwords from the security equation makes passwordless SSH more secure.
Passwordless SSH authentication is typically based on asymmetric cryptography (private and public key pair). You may use an authentication token to store the private key.