Some authentication means are more secure than others: using a hardware device designed to store a private key without making it possible to ever extract it is more secure than storing the private key in a file. Unfortunately the most secure ones are also more painful to use. Users who have their keys on a device need to carry the device with them, need to type their PIN code every time they initiate a SSH session, etc. This makes it quite difficult to advocate ways more secure than passwords and files for use cases where the security of the access is not the priority.

So the question is: is it possible to store the authentication material more securely than in a file (which can be stolen by some malware), without changing the user experience?

And the answer is: yes, using a TPM!