On the Feasibility of 256-Bit Prime Field Arithmetic via PMNS on 8-Bit Architectures
摘要
This paper investigates the design of a Polynomial Modular Number System (PMNS) for 256-bit prime field arithmetic on 8-bit architectures. To fit coefficients into 8-bit words, we target a basis matrix \(\textbf{B}\) with \(\left\| \textbf{B}\right\| _{1}<2^8\) and dimension \(n>31\) . We first demonstrate that standard LLL reduction is effective, achieving this 8-bit target for a wide range of parameters and approaching the heuristic theoretical limits for small \(\gamma \) . However, for large \(\gamma \) or as the dimension grows, a gap emerges between LLL’s output and the theoretical minimum. We prove the existence of a global minimum and propose a local-improvement framework using Integer Linear Programming (ILP). This work establishes LLL as a powerful initializer and provides a principled algorithmic foundation for purpose-specific PMNS optimization.