Development Of Passive Entry Passive Start And Research On Encryption Algorithm

Passive Entry Passive Start (PEPS) is the development tendency of vehiclesecurity system. It greatly improves the safety and comfort of vehic le. This paperresearches on the development of PEPS and encryption algorithm used during theidentity authentication. PEPS system consists of PEPS controller, smart key, lowfrequency (LF) antennas and Electronic Steering Column Lock (ESCL). Thispaper focuses on the development of PEPS controller.PEPS controller is the core component of PEPS system. This paper designsthe hardware and software solution of PEPS controller. The hardware solutionconsists of power protection and sampling module, power management and wakeup module, PEPS LF communication module, immobilizer (IMMO) LFcommunication module, Radio Frequency (RF) receiving module, Switch signalacquisition module, driver module, connector module and MCU module. Thephysical hardware is made and debugged. The software solution focuses on thePEPS specific function realization. The identity authentication process isdesigned in detail and the LF and RF communication criterion and protocol ismade.The smart key location identification method is the key technique of PEPSfunction realization and it is researched in this paper based on Finite ElementMethod (FEM) simulation. The LF magnetic field distribution of PEPS issimulated. The impact of driven current on location identification is analyzed andthe magnetic field distribution generated by LF antennas distributed on car bodywhen it is installed in different ways is researched by simulation. The thresholdof smart key location identification is given. Finally, the simulation method isvalidated by on car measurement. The encryption algorithm used in the process of identity anthentication bearson the safety of PEPS. This paper constructs an encryption algorithm based onpiecewise linear chaotic mapping according to the requirements and theperformance of the algorithm is tested and analyzed. The test results show thatthe encryption algorithm has a strong diffusion and confusion. Every bit ofplaintext can influence many bits of cip hertext and the relationship betweenciphertext and secret key is well hidden. In addition, this algorithm has a strongcollision resistance, keys security and rapidness.