CAN Transceiver Secure Update via Disposable Authentication

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Solution Overview

Problem

The CAN system, originally designed without security considerations, is now exposed to external access, posing security and safety risks, and existing cryptographic solutions are resource-intensive and not feasible due to bandwidth and processing limitations, necessitating a secure update mechanism for rules sets without complex cryptography.

Innovation Solution

A two-step authentication process using a trusted node to verify updates, where the authentication code is not stored and can only be used during the second step, requiring an attacker to compromise two nodes, and utilizing a cyclic redundancy check for verification without complex cryptography.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cryptographic algorithms are used for authentication and integrity verification, then security protection is improved, but processing time and storage requirements increase significantly

Engineering Contradiction:
Improvesecurity protectionVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent uses a disposable authentication code that is generated for each update transaction and discarded after use. This eliminates the need for complex cryptographic key management and long-term storage of sensitive authentication data, significantly reducing processing time and storage requirements while maintaining security. The authentication code is transmitted in clear text but can only be used once, making it effectively secure without requiring heavy cryptography.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If cryptographic algorithms are used for authentication and integrity verification, then security protection is improved, but storage requirements increase due to extensive use of non-volatile storage

Engineering Contradiction:
Improvesecurity protectionVSAvoidstorage requirements
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The authentication code is treated as a disposable object that is generated, transmitted, and discarded in a single transaction cycle. It does not require persistent storage in non-volatile memory, unlike cryptographic keys that must be stored securely for repeated use. This dramatically reduces the storage burden on the transceiver while maintaining authentication security.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent extracts the authentication function from the transceiver itself and relocates it to an external authentication server. The transceiver only needs to store minimal configuration data, while the complex authentication logic and credential storage are performed externally. This extraction reduces the storage requirements of the transceiver while maintaining strong security through server-side credential management.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If secure transceivers implement message killing and filtering rules, then security against rogue attacks is improved, but device complexity increases

Engineering Contradiction:
Improvesecurity against rogue attacksVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary authentication server that handles the complex security logic externally. Instead of embedding complex authentication and credential verification logic within each transceiver, the system uses an intermediary service that performs these functions centrally. This reduces device complexity while maintaining strong security through centralized credential management and authentication decision-making.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3565212B1Method for providing an authenticated update in a distributed network
Publication Date: 2021.04.21 NXP BV
  • EP3565212B1 patent drawingFigure 1
  • EP3565212B1 patent drawingFigure 2
  • EP3565212B1 patent drawingFigure 3

AI summary

A method for providing an authenticated update in a distributed network is provided. The distributed network has a plurality of nodes coupled to a serial bus. The method begins with transmitting a credential from an external device to a first node. The update data and an authentication code are provided to a processor of a second node from the external device. The processor of the second node provides the update data and the authentication code to the transceiver of the second node. The authenticated update is finalized by the processor of the second node. The authenticated update is closed by the transceiver of the first node. The credential of the authenticated update is provided to the transceiver of the second node. The transceiver of the second node verifies the update data using the credential and the authentication code. After being verified, the authenticated update data is stored.