A registration authority in general is assigned the task of creating and maintaining lists of alpha-numeric codes or other identifiers to specific organizations, commercial, financial or electronic products, and data. There are close to 100 different international registration authorities approved by the International Organization for Standardization (ISO), founded in 1947, and headquartered in Geneva, Switzerland, that cover registration authority for everything from computer graphics to motor vehicles and national currencies. Not all registration authority is governed by ISO standards, however, with the International Cultivar Registration Authority (ICRA) being a prime example of a global registration authority for assigning formal botanical names to plant cultivars without using ISO protocols. At least half of the widely used ISO registration authorities are focused on the Internet sector to uniquely identify standards for data exchange and network communication.
One of the most prominent areas for registration authority is that of Internet Protocol (IP) address and domain name assignment used to establish unique nodes of identification on the Internet, which is governed by the Internet Assigned Numbers Authority (IANA). The IANA complies with various ISO standards in the issuing of unique identifiers. For example, ISO code 3166-1 alpha-2 governs two letter country codes that the IANA uses to assign national locations for domain names. Worldwide, as of 15 April 2011, there were over 130 million active domain names registered and over 396 million that had been removed from the registration authority. Registration of domain names takes a bottom up approach, with a National Internet Registry (NIR) acting under the umbrella of a Regional Internet Registry (RIR) to coordinate the assignment of names through the IANA's operative branch in the United States, known as the Internet Corporation for Assigned Names and Numbers (ICANN).
Continued expansion of the use of registration authority across an extremely wide variety of commercial and private sector interests interacting over the Internet makes it increasingly necessary to properly secure the individual identifiers for each item and category. Unique identifiers must be established for everything from the thousands of different products that use Merchant Category Codes (MCCs) for proper government taxation under ISO standard 18245, to musical and audiovisual works, electronic books and documents, transaction communication codes, data interchange codes between computer systems, and more. The established method of making sure each transmission is secure involves the use of Transport Layer Security (TLS). Asymmetric-key cryptosystems like TLS encrypt all data and its registered identifiers while in transit over the Internet. This allows a registration authority, as well as other Internet traffic, to maintain a singular control structure over the many complex human transactions occurring moment by moment online, and to reduce them from encrypted global traffic down to individual levels of meaning.