Vehicle Control Message Batching for CMAC Verification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing systems for verifying messages in motor vehicle control units are inefficient and resource-intensive, particularly when dealing with multiple messages, leading to communication overhead and potential security vulnerabilities.

Innovation Solution

A computing device configured to temporarily store received messages and transmit them in bulk to a cryptographic module for verification, using a key-based message authentication code (CMAC) to ensure authenticity, while integrating the cryptographic module with the computing device for efficient processing and minimizing communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If messages are verified individually by the cryptographic module, then verification accuracy is maintained, but communication overhead increases and processing efficiency decreases

Engineering Contradiction:

Improvemessage verification efficiencyVSAvoidcommunication overhead

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent combines multiple individual message verifications into a single batch verification operation. The cryptographic module receives a batch of messages and their authentication codes, verifies them collectively, and returns results for all messages in one communication cycle, thereby reducing communication overhead and improving processing efficiency

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The computing device prepares messages and their authentication codes in advance before transmitting them to the cryptographic module. This preliminary preparation allows the cryptographic module to perform batch verification without sequential communication interruptions, optimizing the verification process

Inventive Principle:

Principle #10Preliminary action

2Reliability

If all received messages are transmitted to the cryptographic module for verification, then security is enhanced, but resource consumption increases

Engineering Contradiction:

Improvemessage authentication securityVSAvoidcomputing resource consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the verification parameter from individual message verification to batch verification. By verifying multiple messages simultaneously with a single authentication code set, the system maintains security for all messages while reducing the total computational resources required compared to sequential verification

Inventive Principle:

Principle #35Parameter changes

3Speed

If messages are processed before verification, then processing speed is improved, but security is compromised

Engineering Contradiction:

Improvemessage processing speedVSAvoidsecurity vulnerabilities

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent implements continuous batch verification where messages are continuously received, prepared with authentication codes, and transmitted for verification without interruption. This continuous process ensures that no message is processed before verification while maintaining high throughput and processing speed

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentEP3900275B1Computing device and method for operating a computing device

Publication Date: 2026.01.07 ROBERT BOSCH GMBH

Figure 1~4
Figure 5a~9

AI summary

The invention relates to a computing device for a control apparatus of a motor vehicle, wherein the computing device is designed to receive messages from at least one external unit, wherein the computing device is designed to at least temporarily save the received messages and to transmit a plurality of the received messages to a cryptographic module which is designed to carry out a check of the transmitted messages.