The RFID Card

I don't exactly remember what year in high school it was, but there was a kid in my class, let's call him Scott, that somehow somewhere was able to obtain one of the RFID cards that would get anyone entry into the school. Essentially, an RFID card is a plastic card with a chip inside and a coil. When the card is placed near a sensor, the electromagnetic field that the sensor puts out is inducted through the card's coil, and power is fed to the chip inside. The chip then emits a wireless string of numbers that the sensor receives, and then either accepts or rejects the card. If it accepts the card, the door unlocks. The doors could be opened simply by holding your wallet with the card inside up to the sensor. Getting this card was one hell of an achievement, and came before I ever got the master key. He realized that he now had quite a bit of power, and wanted to sell it. He had no idea how to copy these cards, and so came to me, one of the nerdier kids of the class. I did a bit of research and found that he could buy an Arduino microcontroller and an RFID read/write shield and be able to read, store, copy and write RFID cards. He bought everything he needed, totaling about $70. I helped him write and set up the code, and load it onto the Arduino. After that, we were successful in reading the number emitted by the RFID card, and then store and write that number to writable cards that he had bought with the Arduino. Once we successfully wrote and tested our first card, we felt very accomplished, but also realized that some people could actually do a lot of unnecessary harm to the school, and so I backed out. Scott decided to go on his own and sell the cards himself, leaving me completely out of it, which I was very happy about. He sold a few cards, I don't recall for how much, and apparently made some decent money. As always, though, some people weren't careful enough, and the whole scheme was taken down by the administration. I'm sure that there are still a few people out there that have a card (at least I do), and surely it will come in handy come senior prank time. Scott had an out of school suspension for three days, and was "sentenced" to an extra 30 hours of community service inside the school. At the time, a lot of people were actually expecting him to get kicked out, but he graduated along with me a year or two later. It was a fun time, but that is an example of a failed business startup. That taught me a valuable lesson, if you're going to start a business, at least let it be legal.