A transaction can be done with just a quick swipe of a credit card. This is made possible by magnetic encoding, a technology that is often forgotten.
Magnetic encoding is the way that information is stored on a magnetic stripe, which is similar to a small cassette tape. Credit cards have a magnetic stripe that has a high coercivity and is less likely to get erased. The stripe has three tracks, and each track is coded with information about the card, such as the name of the user, the account number, and other details.
How it works: A magnetic stripe writer is used to code the information on the magnetic stripe. The writer makes a magnetic field that lines tiny magnetic particles in the stripe. This is how the card's information is actually stored. When you swipe a card through a reader, the magnetic head of the reader decodes the magnetic fields, gets the stored information, and sends it to the bank to be approved.
Security implications: The magnetic stripe changed the way people paid for things, but it also raised worries about card duplication and theft. To stop this, credit cards now come with both magnetic stripes and EMV chips. The identity code on these chips is always changing, which makes them more secure than static magnetic stripes.
Transition to contactless: Magnetic encoding is also important for contactless cards, which have a magnetic stripe and a radio-frequency identification (RFID) chip. The chip talks to the card reader electronically, so you can pay without touching anything. Even though the technology behind smart cards is different, encoding is still very important, even if it is done in a different way.
Noteworthy is that cardmanufacturers and banks are now starting to phase out cards with these magnetics stripes. Nonetheless, magnetic encoding is an idea that we take for granted, but it is important to our daily lives. It shows that magnetic technologies are still useful, even as we move into an age of contactless payments and digital accounts. As we continue to make payments easier, it is still important to understand how technologies like magnetic encoding work.