Security question

A security question is used as an authenticator by banks, cable companies and wireless providers as an extra security layer. They are a form of shared secret.

Financial institutions have used questions to authenticate customers since at least the early 20th century. In a 1906 speech at a meeting of a section of the American Bankers Association, Baltimore banker William M. Hayden described his institution's use of security questions as a supplement to customer signature records. He described the signature cards used in opening new accounts, which had spaces for the customer's birthplace, "residence", mother's maiden name, occupation and age. Hayden noted that some of these items were often left blank and that the "residence" information was used primarily to contact the customer, but the mother's maiden name was useful as a "strong test of identity". Although he observed that it was rare for someone outside the customer's family to try to withdraw money from a customer account, he said that the mother's maiden name was useful in verification because it was rarely known outside the family and that even the people opening accounts were "often unprepared for this question". Similarly, under modern practice, a credit card provider could request a customer's mother's maiden name before issuing a replacement for a lost card.