Information Technology Reference
In-Depth Information
The US government initially stated that Social Security numbers (SSNs) would be
used solely by the Social Security Administration and not as a national identification
card. In fact, from 1946 to 1972, the Social Security Administration put the following
legend on the bottom of the cards it issued: “FOR SOCIAL SECURITY PURPOSES—
NOT FOR IDENTIFICATION.” However, use of the SSN has gradually increased. Pres-
ident Roosevelt ordered, in 1943, that federal agencies use SSNs as identifiers in new
federal databases. In 1961 the Internal Revenue Service began using the SSN as the
taxpayer identification number. Because banks report interest to the IRS, people must
provide their SSN when they open a bank account. The SSN is typically requested on
applications for credit cards. Motor vehicle departments and some other state agencies
received permission to use SSNs as identification numbers in 1976. The IRS now requires
parents to provide the SSNs of their children over one year old on income tax forms in
order to claim them as dependents. For this reason, children now get a SSN soon after
they are born. Many private organizations ask people to provide SSNs for identification.
The SSN has become a de facto national identification number in the United States.
Unfortunately, the SSN has serious defects that make it a poor identification num-
ber. The first problem with SSNs is that they are not unique. When Social Security cards
were first issued by post offices, different post offices accidentally assigned the same SSN
to different people. In 1938 wallet manufacturer E. H. Ferree included sample Social Se-
curity cards in one of its products. More than 40,000 people purchasing the wallets from
Woolworth stores thought the cards were real and used the sample card's number as their
SSN [73].
A second defect of SSNs is that they are rarely checked. Millions of Social Security
cards have been issued to applicants without verifying that the information provided
by the applicants is correct. Many, if not most, organizations asking for a SSN do not
actually require the applicant to show a card, making it easy for criminals to supply fake
SSNs.
A third defect of SSNs is that they have no error-detecting capability, such as a
check digit at the end of the number. A check digit enables computer systems to detect
common data entry errors, such as getting one digit wrong or transposing two adjacent
digits. If someone makes one of these mistakes, the data entry program can detect
the error and ask the person to retype the number. In the case of SSNs, if a person
accidentally types in the wrong number, there is a high likelihood that it is a valid SSN
(albeit one assigned to a different person). Hence it is easy to contaminate databases with
records containing incorrect SSNs [74]. Similarly, without check digits or another error
detection mechanism, there is no simple way for a system to catch people who are simply
making up a phony SSN.
The events of September 11, 2001, resurrected the debate over the introduction of a
national identification card for Americans.
Proponents of a national identification card point out numerous benefits to its
adoption:
