Have you ever wondered why keyless remotes have to be programmed to a car before they work, or why your car’s remote never inadvertently unlocks another car in a crowded mall parking lot? It is because keyless entry and remote start systems use something called rolling code technology. The concept is simple. Every time a signal is sent from your remote to your car, a unique passcode is sent with it to verify the authenticity of the remote used to send the signal. Once a code has been used, it is never used again – preventing the possibility of someone snatching that code out of the air during transmission and using it to gain access at a later time. But this rolling code technology has a well-known flaw – one that, with a little help from you, makes it easy for someone to circumvent the entire system and access your property. All it takes is a $30 homemade device designed by privacy and security research Samy Kamkar.