SSH keys provide cryptographic authentication that is significantly more secure than password-based logins. With key lengths of 2048 bits or more, SSH keys are virtually impossible to brute force, eliminating the risk of weak or compromised passwords.
Unlike passwords, SSH keys cannot be intercepted through network sniffing, keyloggers, or man-in-the-middle attacks. The cryptographic handshake process makes sure that even if traffic is monitored, attackers cannot replay or forge authentication attempts.