High security door keys commonly use magnets embedded in the key as an additional security layer. A lot harder to pick by hand, and also doesn't appear in photo

High security door keys commonly use magnets embedded in the key as an additional security layer. A lot harder to pick by hand, and also doesn't appear in photographs of the key. For car keys manufacturers try to get away from physical keys for years, and for a remote keyfob it's just a cost question. Bidirectional communication allows for good cryptography with challenge-response protocol, but costs more than unidirectional. But then people want to be able to open their car when the battery of their fob is dead ...