Secret Key Registration via Segmented Transformation Equations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In vehicle key systems that perform cryptographic communication, the secret key must be registered in both the vehicle and the portable key device, making it vulnerable to eavesdropping during manufacturing, which can lead to wrongful ID authentication.
Innovation Solution
A system and method that uses a first and second transformation equation to generate and register a secret key, where the first transformation equation is stored in the writer and the portable key device, and the second in the remote communication terminal and vehicle, requiring cooperation to generate the secret key, thereby increasing security by making it difficult to obtain the key.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the secret key is registered in both the portable key device and the vehicle during manufacturing, then the cryptographic communication can be established, but the secret key becomes vulnerable to eavesdropping
Solution Approach 1:
The secret key generation process is segmented into two separate transformation equations: the first transformation equation is stored in the portable key device and the second transformation equation is stored in the vehicle. Each device performs its respective transformation on a shared random number, and neither device alone can generate the complete secret key. This segmentation prevents eavesdroppers from obtaining the full secret key through interception of communication during manufacturing or operation.
2Ease of manufacture
If the secret key is transmitted during manufacturing, then the key can be registered in both devices, but the transmission process exposes the key to security risks
Solution Approach 1:
A random number serves as an intermediary element in the key registration process. Both the portable key device and the vehicle receive and process this random number through their respective transformation equations. The random number acts as a mediator that enables key generation without requiring direct transmission of the secret key itself, thereby eliminating the security vulnerability associated with key transmission during manufacturing.
3Ease of operation
If the portable key device stores all key generation algorithms, then the device can independently generate the secret key, but the memory requirements increase
Solution Approach 1:
The key generation algorithms are segmented and distributed between the portable key device and the vehicle. The portable key device only needs to store the first transformation equation, while the vehicle stores the second transformation equation. This segmentation reduces the memory requirements of the portable key device while maintaining the capability to generate the secret key through cooperative processing with the vehicle.
Data Source
AI summary
A secret key registration system which registers a secret key in a portable key device and vehicle. A first transformation equation is stored in a writer and the vehicle. A second transformation equation is stored in the portable key device and the vehicle. The writer transmits a registration code to the portable key device and generates intermediate data with the first transformation equation of the writer. The intermediate data is transmitted to the portable key device, which generates the secret key from the intermediate data with the second transformation equation. The portable key device transmits the registration code to the vehicle. The vehicle generates intermediate data from the registration code with the first transformation equation of the vehicle, and then generates the secret key from the intermediate data with the second transformation equation.