[throwawaymath]

If you're going to insist on a security analogy involving keys and doors in the real world, a better one would be that the attacker has to search every single atom of the doormat to find the key. If you have PubKeyAuthentication enabled and PasswordAuthentication disabled, the world will end before the attacker finds your key (in expectation).

Changing SSH to a non-standard port is an inelegant solution and doesn't actually bolster security.

[killaken2000]

Does it _harm_ security?

[xorcist]

Perahaps not directly, but it does add to cognitive overhead and makes securing the system as a whole more difficult.

If your environment contains multiple ssh servers running on non-standard ports you would not notice when something out of the ordinary happens.

Something listening to an unexpected port should be something you must look into, not shrug at.

[romeisendcoming]

So standardize on a non-standard port, document it and when you do have ssh probes assume it's targeted rather than just another l33t child running du-jour crack(x).

Moving to non-standard means more sophisticated discovery and possibly a more sophisticated attempt.

[throwawaymath]

No, but it is non-standard. Why do things you don't need to?