A familiar sight at many workplaces, hotels, gatehouses and other areas where corporate security is of paramount importance is the access control keycard, which allows for efficient, intuitive and effective security that ensures inhabitants only enter the areas they are supposed to.

The continued success of keycards specifically compared to traditional keys or smaller and more convenient keyfobs is a mix of familiarity and versatility in their design.

Whilst keyfobs typically can only be used in modern Near Field Communication (NFC or contactless), and conversely keys can typically only be used to open physical locks outside of somewhat esoteric solutions such as magnetic locks or through digital access control, keycards can be as sophisticated or as simple as they need to be.

Keycards can be as simple as a set of bumps pushed into a keycard lock or as complex as a passive RFID system, a magnetic strip, a Weigand interface or a combination of multiple security methods that all fit in the same form factor that fits into any type of cardholder or wallet.

There was an option for every need, and using a different, more sophisticated system needed little additional training or consideration on the part of the user to use effectively.

However, the keycard system is older than one might expect and actually predates the conventional bank cards that the form factor is typically associated with.

What was it first used for?

The First Keycards

The first reference to the keycard system as an access control device is in a September 1954 edition of Popular Mechanics Magazine, where it is part of an automatic, unattended car park system.

The prototype system works by using keycards that “read” a pattern of magnetic metal materials that serve as a code the parking machine recognises. 

If it is accepted, the barrier opens and then closes once the car reaches a certain part of the road to stop other drivers sneaking in.

This system appears to work in reverse compared to most conventional pay-and-go car park systems, which dispense a card, ticket or chip on entry and require payment on exit.

Part of the reason for this is that whilst using a magnetic scanner is remarkably sophisticated, predating magnetic strips and the Wiegand method by decades, the system is, in practice, only looking for one pattern, rather than one per user.

The article notes that new cards are issued at the start of each rental period and the barriers are adjusted to factor in the new security code.

This sounds far closer to the ridge, bump or slot-based systems seen in hotels than the more sophisticated keycard design methods used today, which can have access adjusted on the fly depending on when and if a person should have access.

In 1954, the idea of a central system controlling the locks was somewhat fanciful given that IBM had just launched their first mass-produced computer that year, it took up an entire room and the concept of networking was all but impossible with the technology available.

Once the principle was established, however, the versatility of keycards allowed for extra technology to be easily added.