Despite the wealth of gadgets that are "credit card sized", there's no reason an actual credit card has to have the same form factor, especially if you don't need to swipe it through a machine to read it. BMW has noticed this and is building contact-less payment systems into its car keys. The prototype is "the world’s first multifunctional car key" (I guess they never used a key to open a beer) and uses the SmartMX chip from NXP.

The obvious use is for paying road tolls as you drive, but BMW's bofffins see the keys being loaded up with public transport tickets (think Park and Ride schemes) and re-registering the actual key part with other cars for rental purposes. The irony is that, as the "key" doesn't actually fit into a hole to start the car, it could in fact be shaped like a credit card.

The strength of BMW's system is that it can be read from afar, making in-car payments easy. But that is also the weakness. We like the whole reprogrammable key idea, but do we need it to keep our money (metaphorically) inside? A real credit card sits safely in your pocket and can't be hacked from afar. However "secure" the smart key is claimed to be, there will always be a way to hack the system.

Happily, it also puts a whole new slant on our favorite after party game. Now, when we throw our keys into the middle of the room and pick another set at random, we won't just be going home to sleep with the owner's wife. We'll also get to spend his money.

Press release [NXP. Thanks, Melissa!]

Photo: blueoneiam/Flickr