Internet Identifiers: A Survey of History, Challenges, and Future Perspectives

Identity systems are fundamental to any network, just as a language is shaped by a consistent set of symbols and their interpretation. A network is defined by a consistent set of identities and their usages. However, as pressures mount to customize and adapt these identity spaces, one ponders how a network sustains its utility through coherence. This study investigates evolving Internet identifiers and their supporting systems. It includes a historical survey, a synthesis of existing and relevant literature, and a discussion of challenges and future perspectives. Owing to the multi-disciplinary nature of the topic, this paper draws perspectives from a wide array of sources that contribute to Internet systems and digital library systems, synthesized to enhance understanding. Initially, this paper highlights the dynamism and role of namespaces, focusing on the critical need to maintain coherence in the public domain. It also discusses the impact of mobility and digital cloning on identifiers and explores their influence on identity and location. In addition, key Internet identifiers are analyzed, contrasting them with methodologies adopted by digital library systems to provide deeper insights into various identity models. Furthermore, this study delves into the evolution of the Domain Name System (DNS) as an identity system, examining the tensions and adaptations necessitated by customization demands. Finally, this paper explores alternative namespaces beyond the DNS, considering potential responses to these evolutionary pressures and future implications.