Magnetic Stripe Card - The Magnetic Stripe

The Magnetic Stripe

Initially IBM considered and rejected using bar codes and perforations, because these methods did not offer sufficient density of information storage required for the credit cards. Magnetic storage was already known from World War II and computer data storage in the 1950s.

The process of attaching a magnetic stripe to a plastic card was invented at IBM in 1960 under a contract with the US government for a security system.

Forrest Parry, an IBM engineer, had the idea of securing a piece of magnetic tape, the predominant storage medium at the time, to a plastic card base. He became frustrated because every adhesive he tried produced unacceptable results. The tape strip either warped or its characteristics were affected by the adhesive, rendering the tape strip unusable. After a frustrating day in the laboratory, trying to get the right adhesive, he came home with several pieces of magnetic tape and several plastic cards. As he walked in the door at home, his wife Dorothea was ironing clothing. When he explained the source of his frustration: inability to get the tape to "stick" to the plastic in a way that would work, she suggested that he use the iron to melt the stripe on. He tried it and it worked. The heat of the iron was just high enough to bond the tape to the card.

There were a number of steps required to convert the magnetic striped media into an industry acceptable device. These steps included: 1) Creating the international standards for stripe record content, including which information, in what format, and using which defining codes. 2) Field testing the proposed device and standards for market acceptance. 3) Developing the manufacturing steps needed to mass produce the large number of cards required. 4) Adding stripe issue and acceptance capabilities to available equipment. These steps were initially managed by Jerome Svigals of the Advanced Systems Division of IBM, Los Gatos, California from 1966 to 1975.

In most magnetic stripe cards, the magnetic stripe is contained in a plastic-like film. The magnetic stripe is located 0.223 inches (5.56 mm) from the edge of the card, and is 0.375 inches (9.52 mm) wide. The magnetic stripe contains three tracks, each 0.110 inches (2.79 mm) wide. Tracks one and three are typically recorded at 210 bits per inch (8.27 bits per mm), while track two typically has a recording density of 75 bits per inch (2.95 bits per mm). Each track can either contain 7-bit alphanumeric characters, or 5-bit numeric characters. Track 1 standards were created by the airlines industry (IATA). Track 2 standards were created by the banking industry (ABA). Track 3 standards were created by the Thrift-Savings industry.

Magstripes following these specifications can typically be read by most point-of-sale hardware, which are simply general-purpose computers that can be programmed to perform specific tasks. Examples of cards adhering to these standards include ATM cards, bank cards (credit and debit cards including VISA and MasterCard), gift cards, loyalty cards, driver's licenses, telephone cards, membership cards, electronic benefit transfer cards (e.g. food stamps), and nearly any application in which value or secure information is not stored on the card itself. Many video game and amusement centers now use debit card systems based on magnetic stripe cards.

Magnetic stripe cloning can be detected by the implementation of magnetic card reader heads and firmware that can read a signature of magnetic noise permanently embedded in all magnetic stripes during the card production process. This signature can be used in conjunction with common two factor authentication schemes utilized in ATM, debit/retail point-of-sale and prepaid card applications.

Counterexamples of cards which intentionally ignore ISO standards include hotel key cards, most subway and bus cards, and some national prepaid calling cards (such as for the country of Cyprus) in which the balance is stored and maintained directly on the stripe and not retrieved from a remote database.