Moduli Chain is a next-generation decentralized authentication infrastructure designed to unify the authentication of users and devices under a single coherent model. Despite ongoing advances in modern cryptography, structural limitations inherent in current Passkey and PKI-based systems persist. Passkeys are often presented as a solution to password leaks and credential breaches, yet fundamental issues remain—private-key storage risk, centralized public-key dependency, and the inability to verify real device behavior. This research addresses these problems at their root. The system is composed of three core layers: the NullAuth Layer, the Homomorphic Encryption Layer, and the Moduli Chain. The NullAuth Layer eliminates private-key storage entirely through biometric-based dynamic key generation and provides a Moduli Chain–based pairwise authentication protocol. The Homomorphic Encryption Layer encrypts device behavioral data and enables verification without exposing plaintext. The Moduli Chain acts as a lightweight distributed ledger built on the ESC (Encrypted Sequential Commitment) structure, recording commitments, policies, and state transitions. All authentication outputs are normalized to a unified function, Verify() → True/False. The Moduli Token is not exposed to end-users; it is used solely for backend fee settlement. This whitepaper presents a comprehensive technical architecture, token economics, and industrial application framework for Moduli Chain.