Parallel NTT Coefficient Processing for Lattice Cryptography

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hardware accelerators designed for classical public-key cryptography are inefficient for polynomial computations required in lattice-based post-quantum cryptography due to differences in coefficient sizes and arithmetic operations.

Innovation Solution

A method for performing number theoretic transforms (NTTs) on polynomials by dividing input polynomials into multiple polynomials with fewer coefficients, processing these in parallel using a coprocessor with word-length registers, and executing cryptographic operations based on the transformed results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If existing hardware accelerators for classical public-key cryptography are used, then device complexity is reduced, but productivity deteriorates due to inefficiency in polynomial computations

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidhardware architecture complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the polynomial coefficients into multiple groups that can be processed in parallel. Specifically, it divides the input polynomial with n coefficients into multiple polynomials with fewer coefficients each, allowing parallel processing using the coprocessor's word-length registers. This segmentation enables efficient utilization of existing hardware without requiring complete architectural redesign.

Inventive Principle:
Principle #1Segmentation

2Loss of time

If polynomial coefficients are processed individually, then manufacturing precision is maintained, but loss of time increases due to sequential processing

Engineering Contradiction:
Improvecomputational timeVSAvoidparallel processing complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent merges multiple coefficient processing operations into parallel butterfly operations. By organizing coefficients into segments that fit within the coprocessor's word-length registers, it combines multiple individual coefficient transformations into simultaneous parallel operations, significantly reducing total computational time while maintaining accuracy.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If coprocessor registers are used for storage, then loss of substance is reduced, but ease of operation deteriorates due to word length constraints

Engineering Contradiction:
Improvedata processing easeVSAvoidsegmentation complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent changes the parameter representation by transforming polynomial coefficients into a segmented format that matches the coprocessor's word length constraints. It applies number theoretic transforms and modular arithmetic to reorganize data so that coefficients are grouped into segments fitting within register word lengths, enabling efficient in-register processing without requiring complex external memory operations.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS12574237B2Number theoretic transform with parallel coefficient processing
Publication Date: 2026.03.10 NXP BV
  • US12574237B2 patent drawing
  • US12574237B2 patent drawing
  • US12574237B2 patent drawing

AI summary

Electronic device and method for performing number theoretic transforms (NTTs) on polynomials for cryptography uses an arithmetic transformation on an input polynomial with n coefficients to divide the input polynomial into multiple polynomials each with less than n coefficients such that the coefficients of the multiple polynomials add up to n. An NTT transformation is executed on the multiple polynomials such that the coefficients of each of the multiple polynomials are processed in parallel butterfly operations. A cryptographic operation is performed based on the results of the NTT transformation.