Carryless Multiplication for Wireless Message Authentication

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Solution Overview

Problem

Existing message authentication methods in wireless communication systems require a significant number of machine instructions, leading to inefficiencies and potential vulnerabilities in integrity and authenticity assurance.

Innovation Solution

The use of carryless multiplication to compute a universal hash function for generating message authentication codes (MACs) reduces the number of machine instructions required, improving operational efficiency and side-channel security by making wall clock time independent of message bit values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional hash function computation is used for message authentication, then authentication functionality is provided, but the number of machine instructions required is large, reducing operational efficiency

Engineering Contradiction:

Improveauthentication throughputVSAvoidnumber of machine instructions

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical/bit-by-bit hash computation with carryless multiplication operations. This substitution reduces the number of machine instructions from potentially hundreds to just a few, dramatically improving authentication throughput while maintaining security functionality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the computational parameters by using carryless multiplication in finite fields (GF(2^8)) instead of traditional binary arithmetic. This parameter change transforms the hash computation into a more efficient mathematical operation that requires fewer instructions while preserving the cryptographic properties needed for authentication.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If traditional hash computation methods are used, then message authentication is achieved, but wall clock time depends on message bit values, creating side-channel attack vulnerabilities

Engineering Contradiction:

Improveside-channel securityVSAvoidcomputation time variability

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent makes the computation time independent of message bit values by using carryless multiplication, which executes in constant time regardless of the input data. This equipotential approach eliminates timing variations that could be exploited by side-channel attacks, thereby improving reliability without complicating the operation.

Inventive Principle:

Principle #12Equipotentiality

3Reliability

If encryption techniques are used for wireless communication security, then message confidentiality is protected, but additional techniques are still needed to protect message integrity and authenticity

Engineering Contradiction:

Improvemessage integrity and authenticityVSAvoidnumber of security techniques required

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the encryption function with the authentication function by using the same carryless multiplication-based algorithm for both purposes. This combination eliminates the need for separate security techniques, reducing overall system complexity while maintaining both confidentiality and integrity/authenticity protection.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentEP2959630B1Message authentication using a universal hash function computed with carryless multiplication

Publication Date: 2019.03.20 QUALCOMM INC

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AI summary

A method for authenticating a message by a wireless device is described. The wireless device obtains the input message. The wireless device generates a keystream. The wireless device computes a message authentication code using the keystream and a universal hash function. The universal hash function is computed using carryless multiplication.