An anonymous reader alerts us to research out of Belgium and Israel that claims a practical attack on the KeeLoq auto anti-theft cipher. Here are slides from a talk (PDF) at CRYPTO 2007. From the researchers' site: "KeeLoq is a cipher used in several car anti-theft mechanisms distributed by Microchip Technology Inc. It may protect your car if you own a Chrysler, Daewoo, Fiat, General Motors, Honda, Toyota, Volvo, Volkswagen, or a Jaguar. The cipher is included in the remote control device that opens and locks your car and that controls the anti-theft mechanisms. The 64-bit key block cipher was widely believed to be secure. In a recent research, a method to identify the key in less than a day was found. The attack requires access for about 1 hour to the remote control (for example, while it is stored in your pocket). The attacker than runs the implemented software, finds the secret cryptographic key, and drives away in your car after copying the key." Update: 07/23 15:27 GMT by KD : One of the researchers, Sebastiaan Indesteege, pointed out that the link to the paper was incorrect; their paper has not yet been released to the public. I also managed to mis attribute his nationality. He is Belgian, not Dutch. My apologies.