Key Fob Pairing Using Certificates Instead of Transported Secret Keys
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The conventional pairing of wireless key fobs and vehicles requires the transportation of secret cryptographic keys, which poses a risk of theft and necessitates expensive IT systems for security, as multiple key fobs are paired at dealerships without secure authentication methods.
Innovation Solution
A certificate-based authentication process using public and private key pairs, where a pairing device verifies the authenticity of key fobs and control units, generates secret encryption keys, and encrypts operational keys to secure the pairing process, reducing the need for transporting secret information and minimizing IT requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If secret cryptographic keys are transported to vehicle dealers for key fob pairing, then key fobs can be paired with vehicles, but security risk increases due to potential theft of secret keys
Solution Approach 1:
The patent extracts the secret key from the transportation process entirely. Instead of transporting secret cryptographic keys to dealers, the system uses public key infrastructure where only public keys and signed certificates are transmitted. The secret key remains securely stored in the vehicle's control unit and never leaves the manufacturer's secure environment.
Solution Approach 2:
The patent introduces digital certificates as an intermediary mechanism. Rather than directly sharing secret keys between vehicle and key fob, a trusted certificate authority (the vehicle manufacturer) mediates the authentication process by signing the key fob's public key, creating a certificate that proves authenticity without exposing secret keys.
2Reliability
If expensive IT systems are implemented to secure secret key transportation, then security is improved, but system complexity and cost increase
Solution Approach 1:
The patent replaces the physical/mechanical system of secure key transportation (requiring secure IT infrastructure, encrypted channels, and physical security measures) with a cryptographic mathematical system based on public key infrastructure. This substitution eliminates the need for expensive secure transportation infrastructure while maintaining or improving security.
Solution Approach 2:
The patent uses disposable, easily transmittable data objects (public keys and certificates) instead of valuable, reusable secret keys. Public keys can be freely transmitted without security concerns, and if compromised, new key pairs can be generated without affecting the core secret key stored in the vehicle.
3Ease of operation
If multiple key fobs store the same secret key for pairing, then pairing is simplified, but vulnerability to unauthorized access increases
Solution Approach 1:
The patent applies asymmetry by giving each key fob a unique cryptographic identity through individual key pairs and certificates. Instead of symmetric authentication where all key fobs share the same secret, each key fob has asymmetric credentials that are unique yet equally valid for authentication, preventing unauthorized duplication.
Data Source
AI summary
An electronic device, in disclosed embodiments, includes an antenna, transceiver circuitry coupled to the antenna, a memory configured to store a first operation key and instructions, and a processor coupled to the transceiver and to the memory. The processor is configured to execute the instructions stored in the memory to cause the electronic device to, in response to receiving a first transmission containing an encrypted version of a second operation key that is encrypted by the first operation key, decrypt the encrypted version of the second operation key using the first operation key to recover the second operation key, store the second operation key in the memory, transmitting, by a transmitter of the electronic device, a second transmission that contains the first operation key and a command.