Records, Computers and the Rights of Citizens. VII. the Social Security Number as a Standard Universal Identifier


Our charter commissioned us to analyze policy and practice relative to the issuance and use of the Social Security number, including prohibitions, restrictions, conditions, or other qualifications on the issuance and use of the number which now exist, or might be imposed to help implement whatever safeguards for automated personal data systems we might recommend.

This particular aspect of our charge stems from growing public concern that the Social Security number will become a standard universal identifier used by all manner of organizations and data systems to establish the identity of individuals, to link records about them, and generally to keep track of them from cradle to grave. This concern also led to the establishment of the Social Security Number Task Force in February 1970, and was reflected in former HEW Secretary Elliot L. Richardson's testimony, in March 1971, before the U.S. Senate Subcommittee on Constitutional Rights, chaired by Senator Sam J. Ervin, Jr.1

Why do these concerns exist? Are they reasonable? What can be done about them? To answer these questions we must first understand something about identifiers in general and the nature and implications of a standard universal identifier in particular.

There are many kinds of personal identifiers. A person's name is an identifier, the most ancient of all, but is not a reliable one, since often it is neither unique nor permanent. Even unusual names may be widely shared, and because of family patterns identical ones are often concentrated in particular localities. Some names change when people marry or divorce, and when children are adopted. Some people are known by different names in different social settings; e.g., itinerants, persons with aliases, and married women who use a maiden name professionally.

To compensate for the unreliability of names as personal identifiers, additional schemes of identification have been devised. These commonly take the form of numeric or alpha-numeric labels that provide the uniqueness and permanence names customarily lack. The reliability thereby achieved is important to record-keeping systems in order to assure accuracy in merging and updating data to be stored about individuals. Usually such labels are established for a single system, but in some instances, a single one may be used in more than one system; for example, in all the record-keeping systems of an organization that maintains different sets of records on a given group of people. If one label is used by separate organizations, such as the Social Security number is for the taxpayer's identification number, a driver's license number, and a school student number, that label may be on its way to becoming a de facto universal identifier.