# Identifiers & Registries Verifying identity and accessing profile data of people, entities, and objects is a crucial foundational function of digital economies. When moving from physical to digital interactions, the first complication is establishing trust as to the identity of the counterparty. It is crucial that this identity is verifiable: that is, can be authenticated in some means (a mobile one time password, a digitally signed QR code, a biometric fingerprint scan, or even a face ID authentication). A country should have multiple identities to fulfill multiple purposes and functions across sectors, but at least one should provide a foundational capability of authenticating that the individual is who they say they are, **and returning a few commonly required data fields** (such as name, gender, date of birth, and address) via an open API. Functional identities (such as voter IDs, social protection IDs, or driver’s licenses) should also strive to make their profile data accessible via APIs or other digitally native means. An identity system is a registry of persons. Countries also need foundational registries of entities (such as businesses, hospitals, schools, etc.) to allow sector-specific digital service providers to innovate based on shared datasets. These registries should provide digitally signed data to ensure it is tamper-proof and accessible through open APIs (and prevent clunky PDF or Excel downloads) to ensure software can directly consume the information. This greatly enhances the speed of service delivery and the competition across sector-specific market players. Key examples of building blocks in this category of DPIs include: * Authentication (mobile, offline QR code-based, biometric, facial, etc.) * eKYC * Single Sign-On * Civil/Functional Registries * Entity Registries * Object Registries (land, etc.) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.cdpi.dev/technical-notes/digital-ids-and-electronic-registries.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.