What is a Smart Card?

Michael Anissimov
Michael Anissimov

A smart card is any card that has an integrated circuit on it. It does not have batteries, as the size of a card is too small to mount all but the smallest of special-purpose batteries, which are currently too expensive. Because it has no power on its own, the card must be run through a reader to temporarily give it power so that the data on the card can be accessed. The first were used to pay for telephone calls in France.

Smart cards may be used for public transportation.
Smart cards may be used for public transportation.

There are a variety of applications for the smart card, including payment cards, identification cards, access-control cards, cards for public transit, insurance cards, and the SIM cards found in cell phones on the GSM network. When a card contains only memory elements, it is called a memory card. Memory cards, usually a bit thicker and smaller than the type of card that fits in a wallet, are often used to store saved games for video game systems

SIM card, a type of smart card.
SIM card, a type of smart card.

The chip in a smart card will usually hold several processing elements, some of which will be devoted to security and authentication. Because these cards are often used in payment systems, preventing fraud is a high priority. Usually, they come with an associated PIN number, which has to be entered into the reader by the user for all but the smallest transactions. This helps cut back on fraud.

All cards have some form of electronic memory that can be rewritten by an external card reader. For example, in a payment card, the funds available are sometimes represented on the card itself, and when the card reader interacts with the card to perform a transaction, it deducts funds appropriately. On the surface of every smart card is two electrical contacts, through which current flows when the card is inserted into a reader.

The smart card was independently invented and patented by several people throughout the world in the 1970s, when integrated circuits got small enough to fit on something the size of a card. The newest cards contain RFID chips, which permit contactless interactions with card readers, rather than having to put a card into a machine for it to be read. These cards exploded in popularity in the 1990s, and chances are that most people have several in their home, even if they aren't explicitly aware of them.

A phone that uses a SIM card, a type of smart card.
A phone that uses a SIM card, a type of smart card.
Michael Anissimov
Michael Anissimov

Michael is a longtime EasyTechJunkie contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

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Discussion Comments


@NathanG - RFID smart cards (radio frequency cards) are particularly vulnerable to hacking. These little cards are used in military and transportation settings. I read the other day that hackers had succeeded in breaking the encryption codes in these little devices. So to follow up on your point, even these cards are not as secure as once thought.

That’s too bad because I have always been a believer in these RFID cards. Some of them have been used to track birds in flight. At one time I thought it might be a good idea to have really tiny versions of these cards that could be placed in wristbands or watches that kids everywhere would wear to aid law enforcement, in case a child is abducted.

There is good and bad in smart card technology, but we just have to focus on the positive uses while being aware of its dangers.


Smart card phone technology has its advantages and disadvantages. On the one hand I appreciate the ease with which you can switch out your SIM card with different cell phones, especially if you’re traveling overseas and you have a phone that lets you do that.

On the other hand, it’s a little scary to think about the lack of security in having all of your private phone calls and text exchanges on a SIM card. For example, there are SIM readers out there which will read messages on your SIM card, even if they’ve been deleted.

Employers have used these little devices to keep track of what their employees are doing during business travel. It may seem like an invasion of privacy, but unfortunately many employers see the need to do this to protect their businesses from needless liability if the employee does something illegal on company time.


My digital camera has a smart card-a memory chip-and it’s a very convenient storage mechanism for transferring photos to my computer. I have a USB connection on the camera so that I can transfer the pictures, but I can also just pull directly from the smart card.

My computer has a smart card reader writer that reads a variety of data formats. I just plug the memory card into the smart card reader and immediately I can download my camera photos as if they were on an external hard drive.

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