Application principle of automobile radio frequency anti-theft system technology
Jan 17, 2019

  RF anti-theft system technology is widely used in car anti-theft, but do you have a deep understanding of the application principle of this technology? Here, the China Security Network Xiaobian will give a detailed introduction to the application principle of the RF anti-theft system technology. 
    The radio frequency anti-theft system technology uses radio frequency to perform non-contact two-way communication to exchange data for identification purposes. Compared with the traditional magnetic card and IC card , the biggest advantage of the RF card is that it is non-contact, so no manual intervention is required to complete the identification work, which is suitable for realizing the automation of the system and not easily damaged. It can recognize high-speed moving objects and recognize multiple at the same time. RF card, quick and easy operation. In the application of anti-theft of the ignition system of the car, the top of the ignition key is embedded with a radio frequency anti-theft chip . When the driver inserts the ignition key into the slot, the chip transmits a certain number of pulse signals at different frequencies to create a special key string. If this signal is not received, the fuel pump will not work. 
  Early RF anti-theft system technology systems, including keyless entry systems, were 32-bit, meaning that the key consisted of 32 pulsed signals, which had 10^32 arrangements, making it difficult to crack. Later, the more advanced system has 40. 
  These systems look impeccable – at first it was. So, is the system still able to guarantee car safety now? The answer is not guaranteed. 
  Radio Frequency Anti-theft System Technology Automotive System: Signal Radiation Protection 
  RF anti-theft system technology can indeed reduce the rate of car theft, because it is quite difficult to crack. The keyless entry system works almost identically to the anti-theft control system. 
  Keyless entry system with radio transponder setup: the system includes a loop circuit board, a wireless receiver, a battery and an antenna. When the owner is near the car, press the remote control key button. The wireless radio anti-theft system technology chip in the key transmits a 40-bit key signal to the outside. After the response chip in the car receives the signal and correctly matches, the door is unlocked. 
  This type of system is called active radio frequency anti-theft system technology because it is the owner who actively pushes the button to send a signal. The keyless ignition system is a passive radio frequency identification system because it is the receiving end in a two-way system. The keyless ignition system also does not contain a battery (because there is no need to send a signal), and the antenna power is also low. 
  The system's key arrangement is more than one trillion, and seems to be impeccable. However, similar to the safe encryption system, the anti-theft technology of the RFID system will always be cracked after a period of time, so it needs to be continuously updated. 
  At present, cracking the radio frequency anti-theft system technology is the highest technology car theft means. Use a special hardware device to capture the RF signal transmitted in the air and decrypt it with software. In 2005, researchers at Johns Hopkins University in the United States demonstrated how to crack the system. 
  And those cars with access control systems and ignition systems that use wireless radio frequency anti-theft system technology are even more sculptural for crackers. After acquiring the key, it can not only enter the vehicle, but also launch the vehicle. Car safety experts point out that the biggest security hole in such systems is that they can be cracked only by the step of decryption. 
  For the safety experts, the insurance company and the auto industry report a questioning attitude. Admittedly, the researchers did demonstrate how to easily crack the RF anti-theft system technology through the device, but the equipment and cost are also quite high. For car thieves, the need to purchase such a set of equipment for theft of cars seems to be "high price-to-price ratio". 
  However, for large criminal gangs, they are specifically for luxury cars, so the cost of these equipment is negligible. Another very important point is that the radio frequency identification key of each car was not reproducible. Therefore, once the driver accidentally lost his car key, he could no longer match the second one to match the car key. The car key will cause the car's anti-theft security level to drop. Now, in order to solve this problem, all the owners can match the second car key that matches the car key, which also gives the thief a chance.
  Researchers at Johns Hopkins University have proposed several possible system optimization options. First, RF anti-theft system technology manufacturers need to increase the key level from 40 to 128. Second, when the car owner does not use the car, the car key should be wrapped in tin foil to shield the signal. The third and most important point is that car manufacturers should use RF anti-theft system technology as an optional rather than the only security anti-theft system. 
  For any security system, "cascading mashups" are the best way to improve security.

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