>>47
[quote]Now what do you think happens when you have two cards in range? They fuck up your envelope detector and you can read exactly zero of them [/quote]
AFAIK, data is send consecutively, as of, you can't read two cards at the same time. Only one string will be read at one time interval - also depends how your reader's soft is implemented. I could be wrong on that, this is what I concluded from the different sources.
1.
http://www.eng.tau.ac.il/~yash/kw-usenix06/ (note it's 100$. One can get more powerful amplifiers, 1 meter is very possible)
2.
http://www.rf-dump.org/
3.
http://cq.cx/proxmark3.pl
4.
http://www.tombom.co.uk/extreme_rfid.pdf
5.
http://people.cs.umass.edu/~kevinfu/papers/RFID-CC-manuscript.pdf
6. You can buy
factory mass-produced hand-held readers with distances going as far as 15cm, working on 13.56 MHz frequency - on eBay