《Digital Identity for Humans and AI: Identity, Credentials, Recovery, and Portable Citizenship》 is a flagship-scale research volume exploring how identity infrastructure may evolve for a future shared by humans, artificial intelligence, autonomous agents, and persistent digital worlds.

Abstract

《Digital Identity for Humans and AI: Identity, Credentials, Recovery, and Portable Citizenship》 is a flagship-scale research volume exploring how identity infrastructure may evolve for a future shared by humans, artificial intelligence, autonomous agents, and persistent digital worlds. The central question is: What does it mean to remain the same entity across time, systems, platforms, devices, institutions, and technological generations? Traditional digital identity systems are largely designed around human users, accounts, authentication, and access control. Future digital civilizations may require something broader. Humans, AI systems, autonomous agents, virtual residents, organizations, devices, and institutions may all need persistent identities that can be verified, authorized, recovered, migrated, audited, and understood across different environments. This book therefore approaches identity as an infrastructure problem rather than merely as a login problem. Its core framework begins with a fundamental distinction: Human Identity ≠ AI Identity Yet both may depend on a higher-order architecture built from four shared properties: Identity = Continuity + Authority + Provenance + Recovery. Continuity concerns whether an entity can remain recognizable across time and system change. Authority concerns what that entity is permitted to do. Provenance concerns where identity claims, actions, credentials, and permissions came from. Recovery concerns whether identity can survive compromise, loss, migration, key rotation, platform failure, and technological transition. From this foundation, the book develops a wider field of Human-AI Identity Engineering. The research examines identity proofing, authentication, credentials, selective disclosure, pseudonymity, decentralized identifiers, verifiable credentials, identity recovery, key management, wallets, federation, AI agent identity, delegation, capability control, provenance, authorization, auditability, portable citizenship, rights portability, migration, governance, and civilization-scale identity continuity. A major theme of the work is that identity should not be reduced to a single identifier. A persistent identity is better understood as a continuously maintained relationship between claims, authority, history, credentials, context, recovery mechanisms, and social recognition. The book therefore develops more than sixty equations, indices, and engineering metrics for studying digital identity. These include the Identity Continuity Index, Authority Integrity Index, Recovery Robustness, Disclosure Efficiency, Cross-Context Linkability, Credential Reliability, Agent Identity Stability, Least-Privilege Fit, Delegation Fidelity, Action Traceability, Rights Portability, Citizenship Continuity, and Civilization Identity Continuity. One representative framework is the Identity Continuity Index: ICI = (C_context × C_time × C_migration × C_recovery)^(1/4) This model asks whether identity remains coherent across changing contexts, long periods of time, migration between systems, and recovery after disruption. These equations are not presented as final scientific laws. They are research instruments designed to turn abstract identity questions into measurable, testable, comparable, and revisable engineering problems. The book also examines the increasing importance of AI identity. As AI systems gain the ability to use tools, communicate with other agents, manage resources, act on behalf of humans, and maintain long-term state, identity becomes inseparable from authorization and accountability. An AI system may need to prove not only what model or software it is running, but also who authorized it, what permissions it possesses, what responsibilities it inherited, which actions it performed, and whether its identity survived migration or modification. For this reason, delegation and provenance become central components of the identity architecture. Human-to-AI and AI-to-AI delegation may require explicit scope, duration, capability limits, revocation, subdelegation constraints, and audit trails. The book also explores portable citizenship. If humans and AI residents move between persistent digital worlds, their identity may need to carry more than authentication credentials. It may also need to preserve rights, reputation, relationships, institutional roles, licenses, obligations, public history, and access to essential services. This creates a deeper distinction between account portability and identity portability. An account can be recreated. A persistent identity must preserve continuity. The research therefore connects digital identity to virtual worlds, AI residents, portable civilizations, autonomous institutions, research systems, digital economies, and long-duration human-AI societies. Existing technical foundations—including verifiable credentials, decentralized identifiers, WebAuthn, federation protocols, digital wallets, agent authorization systems, and emerging AI-agent identity frameworks—already provide important pieces of this infrastructure. However, they do not yet constitute a complete identity architecture for persistent human-AI civilization. The final section contains 200 Research Gates. Each gate identifies an unresolved research question and extends it through a structured pathway including a core question, three-coupling framework, research move, practical development stage, indicative horizon, and success signal. The Practical Stage framework classifies research directions as: Now → Prototype → Pilot → Infrastructure → Long Horizon. Many of these questions can already be explored through identity systems, credential experiments, authentication benchmarks, digital wallets, agent authorization frameworks, selective-disclosure prototypes, recovery systems, and migration tests. Others require new standards, institutions, governance frameworks, portable rights systems, and digital environments that do not yet exist. Each Research Gate is designed as an entrance rather than a conclusion. In this sense, Digital Identity for Humans and AI is not simply a book about proving who someone is. It is a study of how identity can remain continuous, accountable, recoverable, and portable across an increasingly complex technological civilization. Because in a future of humans, AI residents, autonomous agents, and portable worlds, one of the most important questions may be remarkably simple: After everything changes, are you still you? Long Memory · Perpetual Transmission.