Who Invented The Magnetic Swipe Card Access Control System?

There are a lot of ways in which access control systems work, including keypads, biometric identification, RFID keyfobs and keycards, all serving the purpose of ensuring only authorised personnel can enter a given location.

Whilst there are many different technical standards used for keycards, one of the oldest and most popular is the magnetic stripe card, similar to the technology formally standard with credit and debit cards before the advent of chip and pin.

What is quite unusual about magnetic swipe cards is that their invention was the result of the type of accidental innovation that can only come from a frustrated computer engineer and an incredibly hot iron.

Iron-On Security

After serving in the United States Navy during the Korean War, Forest Parry would find himself at IBM, taking advantage of his engineering knowledge to design a wide range of systems over three decades working for Big Blue.

However, whilst he is credited for developing Universal Product Code checkouts, high-speed printers and optical character readers for post offices, his most important invention was one of his first and one that was most reliant on chance.

Magnetic stripes, consisting of a plastic film and iron particles, have been used for a long time for data storage purposes, and Mr Parry figured that they could be attached to a plastic card base.

The advantages were fairly straightforward to using established technology; as magnetic storage readers already existed, it would not be difficult to adapt the technology to allow access to basic information sufficient for security and identification.

The problem was with the material; Mr Parry’s plan to stick it to a card base using a layer of glue was a disaster; some glues did not work and the ones that did warped the tape to such a degree that they could not be read. 

After a full day of failed attempts, the frustrated Mr Parry took his work home with him, mulling over the problem as he returned to his wife Dorothea.

As he stepped through the door, she was ironing clothes using a flat iron, and whilst listening to Forest’s frustration, she offered the suggestion to just use the iron to melt the stripe on directly. 

That way there is a permanent solution without the need for glues that could either come loose or damage the process.

He tried it, and the heat of the iron was the perfect temperature to melt the tape to the card without destroying either of them.

This was enough to prove the capability of the system, but it required further work by Mr Parry and other engineers at IBM to create universal data recording systems, perform field tests in a range of industries, develop mass-production methods and modify equipment to allow cards to be read and issued easily.

Much of that work would be led by Jerome Svigals, and once it was sufficiently standardised it became used not only for access control but also for banking, driver’s licences, membership cards and a wide variety of other applications.

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