TITLE
PHYSICAL PRINCIPLES AND SECURITY ANALYSIS OF CAR IMMOBILIZER SYSTEMS BASED ON SHORT-RANGE TRANSPONDERS
AUTHOR(S)
Strahil Subev, Dobroslav Dankov
ABSTRACT
This article presents a comprehensive analysis of short-range automotive immobilizer systems using low-frequency (LF) transponder technology operating at 125 kHz. The basic electromagnetic principles governing the inductive coupling between the transponder and the antenna are presented, the factors determining the effec-tive operating range are analyzed, and current security vulnerabilities and strategies for their prevention are evaluated. The study includes mathematical modeling of electromagnetic interactions, range optimization tech- niques, and security assessment of modern cryptographic implementations, including AES-128, Hitag, and Megamos protocols. The analysis shows that although LF-based systems provide inherent resistance to remote attacks due to their limited range (2-10 cm), they remain vulnerable to side-channel attacks, relay attacks, and cryptographic weaknesses. Improved security measures are proposed, including dynamic key rolling, hardware-based protection mechanisms, and secure communication protocols to address the identified vulnerabilities.
DOI
DOWNLOAD
https://unitech.tugab.bg/images/2025/dokladi/2-Electronics%20and%20Sensors/p203_s2_u68_id439.pdf
How to cite this article:
Strahil Subev, Dobroslav Dankov, PHYSICAL PRINCIPLES AND SECURITY ANALYSIS OF CAR IMMOBILIZER SYSTEMS BASED ON SHORT-RANGE TRANSPONDERS, UNITECH – SELECTED PAPERS - 2025