Plactic Monoid Key Agreement Using Knuth Multiplication for Quantum Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Quantum computers pose a threat to traditional key agreement schemes like Diffie-Hellman, as algorithms such as Shor's quantum algorithm can potentially break the security of these schemes, necessitating the development of post-quantum resistant key agreement methods.

Innovation Solution

Utilizing semigroups, specifically the plactic monoid, for key agreement by employing Knuth multiplication to create shared secrets through semistandard tableaus, ensuring security against quantum attacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Diffie-Hellman key agreement is used, then key exchange can be performed efficiently, but security is compromised against quantum computer attacks

Engineering Contradiction:
ImprovesecurityVSAvoidcryptographic system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the mathematical parameters from traditional Diffie-Hellman (modular exponentiation in finite fields) to plactic monoid operations (Knuth multiplication of semistandard Young tableaux). This parameter change provides quantum resistance while maintaining the key exchange functionality, resolving the contradiction between security and system complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent substitutes the traditional cryptographic mechanism (modular exponentiation) with a completely different mathematical mechanism (plactic monoid operations involving Young tableaux and Knuth multiplication). This substitution replaces the vulnerable Diffie-Hellman structure with a quantum-resistant alternative while preserving the essential key agreement function.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If plactic monoid operations are used for key agreement, then quantum resistance is achieved, but computational complexity increases

Engineering Contradiction:
Improvequantum resistanceVSAvoidkey generation speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent performs preliminary actions by pre-computing and storing the semistandard Young tableaux representations of private keys and public parameters. This preliminary preparation reduces the computational burden during actual key exchange operations, mitigating the productivity loss from using complex plactic monoid operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the key agreement process into distinct phases: key generation, public parameter computation, and shared secret derivation. Each phase uses optimized plactic monoid operations specific to that stage, improving overall computational efficiency while maintaining quantum resistance.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4044498B1Method and system for key agreement utilizing plactic monoids
Publication Date: 2025.08.06 BLACKBERRY LTD
  • EP4044498B1 patent drawingFigure 1
  • EP4044498B1 patent drawingFigure 2
  • EP4044498B1 patent drawingFigure 3A~3B

AI summary

A method for key agreement between a first party and a second party over a public communications channel, the method including selecting, by the first party, a first value "a"; multiplying the first value "a" by a second value "b" using Knuth multiplication to create a third value "d", the third value "d" being a semistandard tableau; sending the third value "d" to the second party; receiving, from the second party, a fourth value "e", the fourth value being a second semistandard tableau comprising the second value "b" multiplied by a fifth value "c" selected by the second party; and creating a shared secret by multiplying the first value "a" with the fourth value "e" using Knuth multiplication, wherein the shared secret matches the third value "d" multiplied by the fifth value "c" using Knuth multiplication.