The Smart Key lock can be set, by the owner, to work with any key.
It works quite simply: insert the currently working key, give it a quarter turn, insert a special "learning key", remove the old key and insert a new one.
From that point on, the lock will open with the new key. Pretty amazing.
What's more, this lock uses an anti-bump mechanism that has the highest commercial security rating.
There's a video explaining how it works.