i-numbers are a type of

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...

identifier designed to solve the problem of how any

web resource A web resource is any identifiable resource (digital, physical, or abstract) present on or connected to the World Wide Web.< ...

can have a persistent identity that never changes even when the web resource moves or changes its human-friendly name. For example, if a web page has an i-number, and links to that page use the i-number, then those links will not break even if the page is renamed, the website containing the page is completely reorganized, or the page is moved to another website. Conceptually, an i-number is similar to an

IP address An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...

, except i-numbers operate at a much higher level of

abstraction Abstraction in its main sense is a conceptual process wherein general rules and concepts are derived from the usage and classification of specific examples, literal ("real" or "concrete") signifiers, first principles, or other methods. "An abstr ...

in Internet addressing architecture. The other key difference is that i-numbers are persistent, i.e., once they are assigned to a resource, they are never reassigned. By contrast, IP addresses are constantly reassigned, e.g., your computer may have a different IP address every time it connects to the Internet. Technically, an i-number is one form of an

extensible resource identifier An Extensible Resource Identifier (abbreviated XRI) is a scheme and resolution protocol for abstract identifiers compatible with Uniform Resource Identifiers and Internationalized Resource Identifiers, developed by the XRI Technical Committee at ...

(XRI) — an abstract structured identifier standard developed at

Organization for the Advancement of Structured Information Standards The Organization for the Advancement of Structured Information Standards (OASIS; ) is a nonprofit consortium that works on the development, convergence, and adoption of open standards for cybersecurity, blockchain, Internet of things (IoT), ...

for sharing resources and data across domains and applications. The other form is called an

i-name I-names are one form of an XRI — an OASIS open standard for digital identifiers designed for sharing resources and data across domains and applications.IP numbering (first layer) and

DNS The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to ...

naming (second layer). The notion of a third layer for persistent addressing is not new —

Uniform Resource Name A Uniform Resource Name (URN) is a Uniform Resource Identifier (URI) that uses the scheme. URNs are globally unique persistent identifiers assigned within defined namespaces so they will be available for a long period of time, even after the res ...

s (URNs) and other persistent identifier architectures have been developed for this purposes. However the XRI layer is the first architecture that combines a uniform syntax and resolution protocol for both persistent and reassignable identifiers. At the XRI addressing layer, most resources will have ''both'' i-names and i-numbers. These different XRIs that all point to the same resource are called ''synonyms''. I-name synonyms make it easy for humans to discover and address the resource, while i-number synonyms make it easy for machines to maintain a persistent identity for the resource. For example, if a company changes its name, it may register a new i-name and sell its old i-name to another company, however its i-number can remain the same — and links to the company that use its i-number won't break. Furthermore, all of these forms of XRI ''synonyms'' can be resolved using the same http- or https-based resolution protocol. The results of XRI resolution are an

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable ...

document called an XRDS (Extensible Resource Descriptor Sequence). XRDS documents are the basis for the

Yadis {{Unreferenced , date= November 2013 Yadis is a communications protocol for discovery of services such as OpenID, OAuth, and XDI connected to a Yadis ID. While intended to discover digital identity services, Yadis is not restricted to those. Othe ...

identity service discovery protocol that is now part of

OpenID OpenID is an open standard and decentralized authentication protocol promoted by the non-profit OpenID Foundation. It allows users to be authenticated by co-operating sites (known as relying parties, or RP) using a third-party identity provider ...

. XRIs are also backwards compatible with the DNS and IP addressing systems, so it is possible for domain names and IP addresses to be used as i-names (or, in rare cases, as i-numbers). Like DNS names, XRIs can also be delegated, i.e., nested multiple levels deep, just like the directory names on a local computer file system. For example, a company can register a top-level (global) i-name and i-number for itself, and then assign second- or lower-level (community) i-names and i-numbers to its divisions, employees, etc.

Examples

The following examples conform to the i-number specifications published in th
XDI.orgGlobal Services Specifications
Note that they do not include the xri://'' prefix as this is optional with absolute XRIs. Global I-Numbers * =!1000.a1b2.93d2.8c73 (Personal) * @!1000.9554.fabd.129c (Organizational) * !!1000 (Network — reserved for XDI.org-accredited i-brokers) Community i-numbers (second-level) * =!1000.a1b2.93d2.8c73!3ae2 (Personal) * @!1000.9554.fabd.129c!2847.df3c (Organizational) * !!1000!de21.4536.2cb2.8074 (Network) Community i-numbers (third-level) * =!1000.a1b2.93d2.8c73!3ae2!1490 (Personal) * @!1000.9554.fabd.129c!2847.df3c!cfae (Organizational) * !!1000!de21.4536.2cb2.8074!9fcd (Network)

Examples

See also

External links