Burglar Alarms in Automobiles

A car burglar alarm is a security alarm. It is an electronic device used to discourage theft of the vehicle itself, its contents, or both.
Car alarms emit high-volume sounds, such as a siren, klaxon, previously recorded verbal warning, the vehicle's horn, or a combination thereof when there is any security threat or when conditions for triggering an alarm are met.
The alarm may also flash some of the vehicle's lights, and some of these alarms also notify the car's owner via a paging system. There is also an option to interrupt and stop various electrical circuits so that the car cannot be started.
Car alarms can be divided into two categories: OEM that is built in factory and Aftermarket that are installed later on.
Keyless remote car burglar alarms are generally based on strong cryptography authentication methods, including Radio receiver, Immobilizer, Motion detector and Wireless USB.