A Security Framework for Chemical Functions

TL;DR

This paper introduces a comprehensive security framework for chemical functions, modeling chemical systems as challenge-response primitives, and provides quantitative bounds and verification methods for applications like authentication and key generation.

Contribution

It formalizes chemical function security properties, instantiates the framework with DNA-based constructions, and develops quantitative analysis and verification methods.

Findings

Derived bounds for robustness, unclonability, and unpredictability.

Developed maximum-likelihood verification rules under sequencing noise.

Demonstrated applications in authentication and key sharing.

Abstract

In this paper, we introduce chemical functions, a unified framework that models chemical systems as noisy challenge--response primitives, and formalize the associated chemical function infrastructure. Building on the theory of physical functions, we rigorously define robustness, unclonability, and unpredictability for chemical functions in both finite and asymptotic regimes, and specify security games that capture the adversary's power and the security goals. We instantiate the framework with two existing DNA-based constructions (operable random DNA and Genomic Sequence Encryption) and derive quantitative bounds for robustness, unclonability, and unpredictability. Our analysis develops maximum-likelihood verification rules under sequencing noise and partial-edit models, and provides high-precision estimates based on binomial distributions to guide parameter selection. The framework, definitions, and analyses yield a reproducible methodology for designing chemically unclonable authentication mechanisms. We demonstrate applications to in-product authentication and to shared key generation using standard extraction techniques.