You are correct in that the more keys that exist, the harder it will be to secure all of them. However, the more keys that are required the less valuable any one key becomes.  Multiple keys means there is no longer a single point a failure.  If you need 3 keys to get data, you can have an entire database of keys leak and the information is still safe.<p>I would also love a more detailed description of just &quot;it is impossible because math&quot; that everyone seems to be giving.