# 2.2 Decentralized Identity Authentication (DID) System

The Decentralized Identity Authentication (DID) system is one of the core security components of the AISim ecosystem. It provides a unique identity identifier for each IoE device and AI Agent and manages them in a decentralized manner through blockchain technology. The design of this system ensures the transparency, security, and privacy protection of identity authentication, especially with the integration of Zero-Knowledge Proof (ZKP) technology, which further enhances data privacy and tamper resistance.

* **Decentralized Identity Management**

Each device and AI Agent is assigned a unique identity identifier (DID) via blockchain, enabling decentralized identity management. This allows devices and users to seamlessly switch between different application platforms while maintaining the coherence of identity authentication. Moreover, the DID system supports cross-platform authentication processes, greatly enhancing the flexibility and compatibility of identity management.

* **Device Status Tracking:**

The DID system can track the operational status and lifecycle of devices in real-time, ensuring the health status of all IoE devices in the network is always visible. This device status tracking feature enables network administrators to perform timely maintenance and upgrades on devices, ensuring the efficient operation and long-term stability of the entire IoE network.

* **Zero-Knowledge Proof (ZKP)**

During the identity authentication process, the DID system combines zero-knowledge proof technology to protect the privacy of sensitive information of users and devices (such as identity, location, and status). ZKP technology can complete identity authentication without exposing actual data, thereby ensuring privacy protection and compliance with current strict privacy protection regulations.

* **Access Control Hierarchy**

In combination with ZKP, the DID system has achieved fine-grained access control. Different devices and users can obtain different levels of access permissions based on identity attributes and roles. This not only ensures the security of data and operations but also ensures that sensitive data and operations in a multi-level system are subject to strict access control.
