8 - http://www.paicast-5.rl.ac.uk - a bigger sized aperture for RF radiation (used for satellite communications)
An aperture is essentially a “hole” through with signals enter a system. A lens and a satellite dish are both apertures. As demonstrated with the Hubble space telescope, a bigger lens means you can see further.79 The same goes for RF – a bigger aperture (not a bigger antenna, per se) allows one to read RFID cards from farther away. The implementations of possible “snooper” apertures are far beyond this paper, but it is physically possible to build systems which can read some cards at much greater distances. The important message here is that one shouldn’t rely on physical “limitations” or manufactures’ specs to provide a cloak of privacy, but rather implement security mechanisms despite the physics. Every day, we make advances in science and technology, there is nothing stopping someone from making a device which can read an RFID card from a few hundred feet away as if the two were only a few inches apart.
A.4 ###%20# hWo eNeds nEcryption? ####^%687#
In the beginning, there were cards and there were readers. Cards emitted a signal and always emitted that signal when readers asked for it. All were happy until people started poking around. When the technology to read cards became less secretive and more widespread among the cracker population, the security of this access mechanism was lost. Crackers could interrogate a card and replicate its output. They could fool a reader into thinking their emulator was a real card and thus, they could masquerade as someone they were not – without the person being any wiser.
There’s a nifty article about cloning a prox card at which details a curious engineer’s endeavors to hack a prox card system. Basically, the author figured out how the cards transmitted a signal by looking at the output of a card when blasted with a single frequency of RF energy. He managed, through some complicated procedures, to replicate that signal on request. By recognizing the method by which the bits were encoded onto the waveform, he figured out how to turn a randomly read card with the same specs into a cloned card.
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