Hardening SSH doesn’t generally mean “making the openssh process more secure”. It means “making connecting to your servers more secure”. So turning off password

Hardening SSH doesn’t generally mean “making the openssh process more secure”. It means “making connecting to your servers more secure”. So turning off password auth, or restricting network access to the SSH daemon, or using stronger centralized auth all do that. Most of the risks that affect SSH are around credential lifecycles, weak credentials, and credential compromise.