Authenticated Encryption Reducing Overhead via Merged Digital Signatures

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The Galois/Counter Mode (GCM) algorithm, a standard for authenticated encryption, faces issues with high overhead in transmitting initialization vectors and authentication tags, especially in protocols with small payload sizes, and lacks protection against replay attacks.

Innovation Solution

A method and system that generates a digital signature using a message authentication code (MAC) for both encryption and decryption, incorporates a secure initialization vector (SIV) that is incremented and shared between processor components, and includes a mechanism to authenticate messages by comparing the SIV portions, thereby reducing overhead and preventing replay attacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If GCM algorithm is used for authenticated encryption, then message integrity and authentication are ensured, but transmission overhead increases due to initialization vectors and authentication tags

Engineering Contradiction:
Improvemessage integrityVSAvoidtransmission overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent combines the authentication tag and initialization vector into a single encrypted digital signature. The authentication tag is generated by encrypting a counter value with the initialization vector, and this combined structure is transmitted as one unit, reducing the number of separate fields that need to be sent while maintaining both authentication and encryption functions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts the counter value from the traditional GCM structure and integrates it directly into the digital signature encryption process. The counter value is encrypted alongside the message using the initialization vector, eliminating the need for separate counter transmission and reducing overall overhead.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If traditional encryption methods are used, then encryption functionality is provided, but protection against replay attacks is insufficient

Engineering Contradiction:
ImprovesecurityVSAvoidencryption mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements preliminary action by incorporating a counter value that is incremented with each message transmission. This counter is encrypted along with the message using the initialization vector, creating a digital signature that inherently prevents replay attacks. The counter ensures that even if a message is captured and retransmitted, the incremented counter value will cause authentication to fail.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If digital signature encryption is implemented, then replay attack protection is achieved, but processing complexity increases

Engineering Contradiction:
Improvereplay attack protectionVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by designing the digital signature encryption mechanism to simultaneously achieve multiple security objectives: message authentication, integrity protection, and replay attack prevention. The same encrypted digital signature structure serves all these functions, eliminating the need for separate mechanisms and reducing overall processing complexity despite the enhanced security capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3832946B1Method and system of authenticated encryption and decryption
Publication Date: 2024.06.19 APTIV TECHNOLOGIES AG
  • EP3832946B1 patent drawingFigure 1A
  • EP3832946B1 patent drawingFigure 1B
  • EP3832946B1 patent drawingFigure 2

AI summary

A method of authenticated encryption and decryption includes generating a first digital signature with an encryption circuit of a first processor component. Concatenating the first digital signature to a plaintext message to generate a concatenated message. Encrypting the concatenated message into a ciphertext. Transmitting the ciphertext via a communications channel to a second processor component. Decrypting the ciphertext into a decrypted first digital signature and a decrypted plaintext message with a decryption circuit in the second processor component. Comparing, with the decryption circuit, the decrypted first digital signature with a second digital signature, thereby authenticating the decrypted plaintext message.