TARDIS Key

The TARDIS Key is shaped like a regular Yale Key but allows access to a user's TARDIS. As a safety system, no one can just create a mold of the key and have thousands of TARDIS keys because the key only works because it has a certain data code imprinted in its atomic structure.

A TARDIS Key is not easily destroyed, quite far from it in fact. TARDIS Key's can survive intense pressure, heat, and cold. But there are certain things that can destroy a TARDIS Key, such as lava or disintegration beams.