A team of Grad students just cracked the "Immobilzer" RFID tag that some car makers are putting in their keys. Immobilizer uses a 40-bit key which isn't all that long. Anyone know what Saab is using for their RFID Keys? I'm not too worried about it as the Saab key has an extremely short range but I've read where Cadillac and Lexus have an RFID key that you don't even need to take out of your pocket. As long as the car detects it, you're good.
For more info on the crack:
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