Smartphone Intermediary Code Generator for Vehicle Access
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Solution Overview
Problem
Existing vehicle access control and start authorization systems lack secure and backward-compatible solutions that allow for the use of smartphones as intermediary authorization devices, while preventing unauthorized access and ensuring compatibility with conventional systems.
Innovation Solution
A Bluetooth-enabled smartphone acts as an intermediary authorization device to a code generator, which communicates with electronic control units in the vehicle via a Bluetooth or RF/LF transceiver, using encrypted keys stored on both the smartphone and the code generator, ensuring secure access and start authorization without storing secret keys in clear text, and allowing for retrofit solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a smartphone is used as an intermediary authorization device, then ease of operation is improved, but security against unauthorized access may worsen
Solution Approach 1:
The patent introduces a smartphone as an intermediary device between the user and the vehicle's authorization system. The smartphone contains a code generator that creates authorization codes, which are then transmitted to the vehicle's control unit. This intermediary approach maintains security by keeping the vehicle's secret keys protected while enabling convenient smartphone-based access control and start authorization.
2Reliability
If encrypted keys are stored on both smartphone and code generator, then security is improved, but device complexity worsens
Solution Approach 1:
The patent segments the authorization system into multiple components: a code generator in the smartphone, a transceiver in the vehicle, and control units in the vehicle. Each component stores only the specific cryptographic material it needs (secret keys in the control unit, authorization codes in the smartphone), rather than all keys centrally. This segmentation improves security through distributed key management while managing complexity by assigning specific functions to each component.
Solution Approach 2:
The smartphone acts as an intermediary that holds encrypted authorization codes and transmits them to the vehicle system. This intermediary role allows the system to maintain security by keeping the vehicle's secret keys protected in the control unit while enabling convenient smartphone-based access. The smartphone's involvement adds a layer of security through encrypted communication without requiring the smartphone to store the vehicle's secret keys.
3Adaptability or versatility
If Bluetooth transceiver is added to vehicle, then adaptability is improved, but device complexity worsens
Solution Approach 1:
The patent implements a transceiver system that supports multiple communication protocols (Bluetooth and optionally RF/LF) to provide universal compatibility. The transceiver can communicate with smartphones using Bluetooth for access control and start authorization, and can also mimic conventional RF/LF key signals for backward compatibility with traditional vehicle systems. This multi-functional approach enables the system to work with both modern smartphone-based access and conventional key systems, improving adaptability while managing complexity through a unified transceiver architecture.
Data Source
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AI summary
An access and start authorization system comprises: a transceiver-and-code-generator module that is configured to be installed in a vehicle, wherein the transceiver-and-code-generator module includes: a Bluetooth transceiver configured to establish a Bluetooth connection with a smartphone; a code generator that is configured to: communicate a secret key to one or more vehicle electronic control units while learning the code generator to the vehicle, subsequently use the secret key to encrypt communications between the code generator and the vehicle, and not store in code-generator memory the secret key in unencrypted form thereby preventing unauthorized access, via the code generator, to the secret key by a person who has access to the vehicle.