Keyless Entry Authentication Using Signal Delay and Power Checks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Keyless entry systems, such as remote-signaling key fobs, are vulnerable to relay attacks where legitimate signals are intercepted and copied, compromising security.
Innovation Solution
A method and device that challenge and authenticate keys by selecting circuits and transmitting challenge signals, analyzing response signal power levels and delays to determine whether to enable entry systems, incorporating multiple RFID circuits with distinct characteristics for authentication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If keyless entry systems use simple signal transmission for ease of operation, then convenience is improved, but vulnerability to relay attacks increases
Solution Approach 1:
The system performs preliminary actions by establishing expected signal characteristics (power levels, time delays, circuit sequences) before authentication occurs. During authentication, these pre-established expectations are used to verify the legitimacy of challenge-response signals, preventing relay attacks while maintaining convenient keyless operation.
Solution Approach 2:
The system implements feedback mechanisms by analyzing response signals from the key and comparing them against expected characteristics. The vehicle system receives challenge-response pairs and uses feedback from this analysis to determine whether to enable entry, creating a verification loop that blocks relay attacks while preserving user convenience.
2Reliability
If the system implements challenge-response authentication with multiple circuits, then security is improved, but device complexity increases
Solution Approach 1:
The authentication system is segmented into distinct functional components: challenge signal transmission, response signal reception, signal characteristic analysis (power level, time delay), and authentication decision-making. The key contains multiple segmented circuits that can be individually challenged and verified, distributing the security function across separate elements that work together to provide robust authentication.
3Measurement precision
If the system analyzes response signal characteristics (power level, time delay), then authentication accuracy is improved, but measurement precision requirements increase
Solution Approach 1:
The system changes parameters of the challenge signals (such as which specific circuits are challenged, signal timing, power levels) between authentication attempts. This variation in parameters makes relay attacks more difficult while the system measures response characteristics against dynamically updated expectations, maintaining high authentication accuracy without requiring excessively precise fixed measurements.
Data Source
AI summary
Aspects of the subject disclosure may include, for example, a device in which a processing system of a remote entry system selects a first circuit from a plurality of circuits of a key remote from the device; wirelessly transmits a first challenge signal to the key, the first challenge signal specifying the first circuit; and wirelessly receives a first response signal from the key, the first response signal having a first response signal power level and a first response signal delay with respect to the first challenge signal. The processing system analyzes the first response signal by comparing the first response signal power level and the first response signal delay respectively with a predetermined first signal power and predetermined first time delay associated with the first circuit; and, in accordance with the comparing, determines whether to enable the entry system. Other embodiments are disclosed.