Code Hopping Security via Dual 64-bit Keys
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing keyless entry systems face challenges in increasing security without compromising RF design efficiency, as stronger encryption algorithms require more data bits, leading to slower reaction times and potential system redesign costs.
Innovation Solution
The integration of secure signature bits into RF code hopping transmissions using two independent encryption keys and a single symmetrical block cipher with CRC calculation, along with a KeeLoq decryption algorithm and a 64-bit Signature Key, enhances security without significantly increasing data packet size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If stronger encryption algorithms with longer keys are used, then security is improved, but data transmission time increases and system complexity increases
Solution Approach 1:
The patent segments the encryption process by using a 64-bit key divided into two 32-bit halves, each processing different portions of the data. This allows parallel processing of encryption operations, maintaining security equivalent to 64-bit encryption while reducing transmission time through concurrent computation.
Solution Approach 2:
The patent applies partial action by using only the necessary portion of cryptographic strength (64-bit effective security) rather than implementing full 128-bit or 256-bit encryption. This provides sufficient security for the application while avoiding the performance overhead of stronger encryption algorithms.
2Reliability
If stronger encryption algorithms with longer keys are used, then security is improved, but device complexity and redesign costs increase
Solution Approach 1:
The patent changes the parameter of key length from traditional 32-bit to 64-bit while maintaining compatibility with existing KeeLoq hardware architectures. By structuring the 64-bit key as two 32-bit halves that can be processed through modified but not completely redesigned encryption logic, the system achieves enhanced security without requiring full system redesign.
Solution Approach 2:
The patent makes the encryption system multi-functional by enabling it to operate with both traditional 32-bit keys and enhanced 64-bit keys using the same hardware platform. This universality allows gradual security enhancement without obsolescing existing infrastructure, reducing redesign costs and complexity.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
An access system includes a transmitter and a receiver for exchange of secure data wherein the system uses an encryption and a decryption algorithm to exchange a secure data packet. The secure data packet may include an unencrypted data packet and an encrypted data packet. The encrypted data packet may include first data encrypted by the encryption algorithm, and data decrypted by the decryption algorithm, wherein the data decrypted by the decryption algorithm includes a combination of a secure signature and second data encrypted by the encryption algorithm.