Fresh-Value Keystream Updates for Secure Vehicle Data Transmission
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Solution Overview
Problem
The security of data transmission between vehicle-mounted devices in intelligent vehicles is compromised due to potential eavesdropping and replay attacks, which threaten the integrity and security of autonomous driving systems.
Innovation Solution
Implement a data transmission method that involves updating encryption keys and keystreams based on fresh values to ensure that a new keystream is used for each message, and includes mechanisms for key synchronization and validation to prevent the reuse of outdated keys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the same encryption key is reused for multiple messages, then the encryption process is simple and fast, but the security is compromised due to potential keystream reuse attacks
Solution Approach 1:
The system performs preliminary key derivation by generating a keystream index from the message sequence number before encryption. This pre-computed index ensures that each message uses a unique keystream segment without requiring complex real-time key generation during the encryption process itself.
Solution Approach 2:
The patent introduces a keystream index as an intermediary element between the base encryption key and the actual keystream. This index, derived from the message sequence number, mediates the selection of unique keystream segments, preventing keystream reuse while maintaining encryption efficiency.
2Reliability
If encryption keys are frequently updated to prevent replay attacks, then security against replay attacks is improved, but decryption delays increase due to key synchronization overhead
Solution Approach 1:
The system implements periodic key updates based on message sequence numbers rather than continuous key changes. Each key update occurs at predetermined intervals (when the sequence number reaches certain thresholds), providing regular security refreshes while avoiding excessive key management operations that would cause delays.
Solution Approach 2:
Both sender and receiver pre-synchronize their key update schedules based on agreed-upon sequence number thresholds. This preliminary synchronization ensures that key updates occur simultaneously at both ends without requiring real-time communication overhead, thus preventing decryption delays.
3Reliability
If message authentication codes are added to verify message integrity, then protection against eavesdropping and modification is improved, but the processing overhead and message size increase
Solution Approach 1:
The patent merges the authentication function with the existing encryption process by using the same keystream derivation mechanism for both encryption and authentication. The message sequence number-based index serves dual purposes: selecting encryption keystream segments and verifying message authenticity, thereby avoiding separate authentication overhead.
Data Source
AI summary
A data transmission method and apparatus are provided. When the data transmission method is applied to a first device, the method includes: when a fresh value corresponding to a message to be sent by the first device is a first fresh value, updating an encryption key from a first key to a second key, and generating a first keystream based on the first fresh value and the second key; encrypting first data based on the first keystream, to obtain the encrypted first data; generating a first message based on the encrypted first data and the first fresh value; and sending the first message to a second device.