The black strip visible on most magnetic key cards is just the surface of a tiny metallic strip on which magnetically charged iron particles are arranged such that they store data. Due to the microscopic nature of these charged arrangements, there are billions of possible combinations. What this means practically is that each time we swipe our UR IDs, or credit cards, or anything else with a magnetic strip, the reader is analyzing the pattern of the strip. Then, it will use that information to determine what access should be granted, or in the case of credit cards, what account should be charged. It is impressive to think that just the action of swiping a card informs a machine of who you are and what following actions should be taken, but that is the ability of this technology.
A magnetic sequence with its own meaning.
Magnetic strips can be produced in two levels of coercivity, high and low. While low coercivity magstrips are less expensive to produce, they also have a much shorter lifespan and can be more easily erased, even by interaction with other magnetic items. These are typically only used for gift cards, season passes, and other such short term needs. Longer term cards, such as credit cards or debit cards, require high coercivity magstrips. These use more magnetic energy to encode, thus making them more difficult to erase. Interestingly, high coercivity strips show up as black on cards, while low coercivity strips tend to be light brown.
A key card being read by a reader.
Recently, common magnetic strip key cards appear to be getting phased out. Many more tech savvy companies and consumers are turning to electronic alternatives such as Apple Pay. This technology does essentially the same thing, reading a user's specifically encoded information in order to decide what to do, but with fewer pieces of hardware. Also, increased abilities from identity thieves and hackers have rendered common magstrips more dangerous. Many magstrip readers can be outfitted to send the information input to recipients beyond just the company receiving the payment. Thus, the trend seems to be to favor chip readers, which are more difficult to breach. Regardless, the magnetic key card has been a huge part of our lives as the world has become more technological.
https://en.wikipedia.org/wiki/Magnetic_stripe_card#/media/File:Aufnahme_der_magnetischen_Struktur_eines_Magnetstreifens_auf_eine_EC-Karte_(Aufnahme_mit_CMOS-MagView)2.jpg
http://www.moosekeycard.com/price.html
I think that the more advanced we become, physical cards will become a thing of the past. We have things like samsung pay and apple pay which actually allow a user to just carry their Id instead of many cards. Do you know if Apple pay has a direct correlation to any programming language? What is the computer Science behind that? Those would be an awesome idea for the next blog. But nice post overall, it is cool to see something we use so naturally be broken down in its usage and function.
ReplyDeleteI think this article is particularly interesting, especially since all of us have spider cards that we regularly swipe. I thought this article was also cool since we had also talked I am curious as to who created the language that the card readers read, and how the lines are on the card are interpreted.
ReplyDelete