Finite-Field Multiplier Circuits With Flexible Limb Partitioning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for multiplying large integers over a finite field face challenges in latency and throughput, particularly in processor-based implementations, and hardware solutions like ASICs and FPGAs face inefficiencies due to non-compatible bit widths and high complexity.

Innovation Solution

A circuit arrangement with an array of arithmetic circuits and a modulo circuit that partitions operands into flexible limb widths compatible with target hardware, allowing efficient mapping to FPGAs and reducing area and power consumption in ASICs, while maintaining high performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If processor-based implementation is used, then flexibility is maintained, but latency and throughput are degraded

Engineering Contradiction:
Improveimplementation flexibilityVSAvoidthroughput
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments the large integer multiplication operation into multiple smaller limb-level operations that can be performed in parallel by multiple arithmetic circuits. The N-bit operands are divided into K limbs, and the multiplication is decomposed into K sets of partial products that are computed simultaneously and then accumulated, enabling hardware parallelism while maintaining flexibility through configurable limb widths.

Inventive Principle:
Principle #1Segmentation

2Productivity

If ASIC implementation is used, then performance is improved, but complexity and cost increase

Engineering Contradiction:
ImproveperformanceVSAvoidcircuit complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces dynamic configurability into the hardware implementation by allowing the limb width to be adjusted based on the specific application requirements. The arithmetic circuits can be configured to work with different limb widths (e.g., 32-bit, 64-bit, or other widths), enabling the same hardware architecture to adapt to different performance and precision requirements without requiring multiple fixed designs, thus reducing overall complexity.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If FPGA implementation with fixed limb widths is used, then hardware efficiency is improved, but adaptability to different bit widths is reduced

Engineering Contradiction:
Improvehardware efficiencyVSAvoidbit width compatibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal arithmetic circuit architecture that can handle multiple different limb widths within the same hardware structure. The circuits are designed to process limbs of configurable width, allowing the same FPGA implementation to efficiently support different bit width requirements (e.g., 23-bit, 32-bit, 64-bit limbs) by simply reconfiguring the parameters rather than requiring separate hardware designs for each bit width.

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

4Device complexity

If N is assumed to be an integer multiple of limb bit-width, then implementation simplicity is improved, but efficiency is degraded

Engineering Contradiction:
Improveimplementation simplicityVSAvoidmultiplication efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent changes the fundamental parameter assumption from requiring N to be an integer multiple of the limb bit-width to allowing any N-bit operand to be divided into K limbs of configurable width. This parameter change enables more efficient utilization of the full N-bit operand space, as the limb width can be optimized to match the specific hardware capabilities and application requirements rather than being constrained by fixed mathematical relationships, thereby improving multiplication efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS12524206B2Circuits and methods for multiplying large integers over a finite field
Publication Date: 2026.01.13 XILINX INC
  • US12524206B2 patent drawing
  • US12524206B2 patent drawing
  • US12524206B2 patent drawing

AI summary

Multiplication of integers over a finite field involves an array of arithmetic circuits configured to input a-limbs, d-limbs, and r-limbs. The array determines an intermediate term, Z, having z-limbs 0 through K by determining respective sets of intermediate z-limbs 0 through K−1 for r-limbs i for i=0 to K−1, and summing corresponding ones of the intermediate z-limbs of sets i through K−1. The arithmetic circuits determine for r-limb 0, intermediate z-limbs 0 through K−1 of set 0 as products of r-limb 0 and a-limbs 0 through K−1, and for the remaining r-limbs determines intermediate z-limbs using different combinations of a-limbs, r-limbs, modulus, and d-limbs. A modulo circuit computes Gas (most significant M bits of Z*m)+(least significant Q bits of Z, wherein Mis a number of bits by which a number of bits of Z exceeds N, and Q is equal to M+ceil (log2 m), and increases G by m if bits Q through N−1 of Z all having bit value one, and G≥2Q−m. Circuitry assigns bits G bits 0 through Q−1 to Y bits 0 through Q−1, and G bit Q to Y bit Q.