Ledger Nano X

Hardware Security Keys - Ledger Nano X
Ledger Nano S is a hardware security key that can be used to securely store SSH keys and authenticate SSH sessions.
The Ledger-agent software is a command-line utility that allows you to use your Ledger Nano S to authenticate SSH connections without exposing your private keys to the network or the computer you are connecting from.
The Ledger Nano X supports several different types of public keys, including RSA, ECDSA, and Ed25519.
While RSA keys are still widely used, newer key type Ed25519 are generally considered to be more secure and efficient.

To use Ed25519 keys with the Ledger Nano X and Ledger-agent software, you can simply use the command

 ledger-agent -e ed25519 user@host 
The key generation is based on the identity and host, so it cannot be changed.
use the -c to connect rather then generate a key
 ledger-agent -e ed25519 -c user@host 

Benefits of using hardware security keys like the Ledger Nano X for SSH authentication include increased security and protection against key theft or compromise, as well as convenience and ease of use.