<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>I've seen the RFID passport walled demonstrated at Defcon last year. It appears to work fairly well.</div><div><br></div><div>As for grounding Faraday cages, it seems to me that for this type of application you don't need to ground the cage. I believe that you only need to ground the cage when you are dealing with extremely high electromagnetic fields that would generate a current. </div><div><br></div><div>According to that page : </div><div><br></div><div>"The metal layers are grounded to <b>dissipate any electric currents
generated from the external electromagnetic fields</b> and thus block a
large amount of the electromagnetic interference"</div><div>(My emphasis)</div><div><br></div><div>For what its worth, tinfoil does a pretty good job at the higher frequency RFID, not so much for the lower. </div><div><br></div><div><a href="http://www.rfid-handbook.de/rfid/frequencies.html">http://www.rfid-handbook.de/rfid/frequencies.html</a></div><div><br></div><div>73, de K6EF</div><div><br></div><br><div><div>On Feb 3, 2010, at 11:14 PM, Christie Dudley wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">One of the things Chris mentioned at his workshop is that the little shields that they issue with passports/North American travel cards do not work. You may as well just wrap your stuff in plastic. What he did demonstrate, however, is that a little tinfoil in your wallet goes a long ways to blocking the signal. <div>
<br></div><div>Christie<br clear="all">_______<br>"The road of excess leads to the palace of wisdom." -- W. Blake.<br>
<br><br><div class="gmail_quote">On Wed, Feb 3, 2010 at 1:56 PM, David Stainton <span dir="ltr"><<a href="mailto:dstainton415@gmail.com">dstainton415@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Yeah nevermind... There's nothing to block here.<br>
If people want to play with RFID that's cool.<br>
I may even help... but let's not misuse it.<br>
<br>
I have also been issued credit/debit/atm cards with RFID.<br>
After the first RFID workshop; as per Chris Paget's suggestion, I<br>
promptly microwaved them in<br>
the Noisebridge microwave for about 2 seconds.<br>
There was a satisfying and noticeable rectangular shape that appeared<br>
on the card...<br>
Also a well aimed smashing with a hammer may work as well.<br>
I have since gotten rid of all RFIDs that I used to carry before I was informed.<br>
<br>
As for the passport issue; I don't have a solution and I'm not real<br>
enthused about the shielding wallets.<br>
It would be interesting to perform experiments to see just how well these<br>
RFID shielding passport wallets actually work. These wallets do not<br>
completely encase<br>
the RFID chip... so the RFID chip could still be some exposured to radiation.<br>
<br>
I was thinking to make my own passport RFID shielding wallet out of<br>
sheet metal so that the passport<br>
could be shielded from all directions.<br>
But really the best shielding would be a faraday cage<br>
(<a href="http://en.wikipedia.org/wiki/Faraday_cage" target="_blank">http://en.wikipedia.org/wiki/Faraday_cage</a>);<br>
and it that case the metal would be grounded. Not really possible to<br>
have a portable faraday cage in that case.<br>
<br>
<br>
~david415<br>
<div class="im"><br>
On Wed, Feb 3, 2010 at 9:40 AM, Ian Atha <<a href="mailto:thatha@thatha.org">thatha@thatha.org</a>> wrote:<br>
</div><div><div></div><div class="h5">> + Changing Subject--Door Bell != RFID Access System.<br>
><br>
> David,<br>
><br>
> I find your concerns valid and I sympathize with them, to a certain extend.<br>
><br>
> I was wondering if you would be willing to describe to us what<br>
> measures you are currently taking to protect yourself from such<br>
> surveillance.<br>
><br>
> I have been issued credit and debit cards with mandatory RFID tags, my<br>
> work badge is using some sort of RFID technology, and I've often found<br>
> RFID tags in products I have purchased. All these, assuming the emit a<br>
> constant value when read, could be used to track an individual.<br>
><br>
> How do you currently protect yourself?<br>
><br>
> Out of curiosity, would you be concerned if someone implemented a<br>
> smart-card based system? I presume that someone motivated enough could<br>
> target the electromagnetic noise emitted by a reader reading your<br>
> smartcard--the attacker wouldn't be able to track you around the<br>
> globe, but they'd know your Noisebridge visiting patterns.<br>
><br>
> Lastly, what do you mean by "block the [...] motion". Although a<br>
> Noisebridge newbie, my understanding was that if someone is willing to<br>
> do something, they may do so. If the group decides an RFID tagging<br>
> system is unwelcome, there would have to be consensus on "ban RFID<br>
> systems from Noisebridge", no? What am I missing?<br>
><br>
> Thank you,<br>
><br>
> -ian.<br>
><br>
><br>
> On Wed, Feb 3, 2010 at 02:02, David Stainton <<a href="mailto:dstainton415@gmail.com">dstainton415@gmail.com</a>> wrote:<br>
>> Greetings Blaine,<br>
>><br>
>> I've got to say that while I appreciate your enthusiasm in getting<br>
>> this doorbell problem solved I think<br>
>> RFID is a horrible technology for that purpose...<br>
>><br>
>> I know a thing or two about RFID from hanging out with Chris Paget who<br>
>> graciously taught a couple<br>
>> of RFID workshops at Noisebridge...<br>
>><br>
>> There is just now way I'm going to walk around with an RFID tag and I<br>
>> don't recommend anyone else do it either.<br>
>> The presence of an RFID tag can be detected from across the street or<br>
>> perhaps even farther away.<br>
>> RFID sensors could in fact be placed around the city to track the<br>
>> movements of Noisebridgers.<br>
>> Or how about a public-garbage-can that explodes when a certain number<br>
>> of Noisebridges congregate near it?<br>
>> Sound crazy? I'm sure that similar devices are being developed for<br>
>> sucka fool US passports with the new RFID tag...<br>
>><br>
>> I will block the RFID access control motion. I will explain to all my<br>
>> Noisebridge friends my view on this matter.<br>
>> I won't be the only one to enthusiastically disagree.<br>
>><br>
>> Please give it some thought before responding.<br>
>> BTW this seems to be your first post to the noisebridge-discuss list<br>
>> and you are suggesting this. Wow.<br>
>><br>
>> Cheers<br>
>><br>
>> ~david415<br>
>><br>
>><br>
>><br>
>> On Tue, Feb 2, 2010 at 10:31 PM, Blaine Forbort <<a href="mailto:b.forbort@gmail.com">b.forbort@gmail.com</a>> wrote:<br>
>>> I had a hell of a time getting in on Sunday. There where a ton of people<br>
>>> near the buzzer, so I found it very odd that no one let me in. Then a few<br>
>>> hours later someone reported that they had been buzzing for 10+ minutes, and<br>
>>> even though I was sitting near the buzzer, I only heard the buzzer go off<br>
>>> once and answered it immediately.<br>
>>><br>
>>> I also spoke to another individual about the idea of an RFID system for the<br>
>>> gate. The concept was very simple: a pool of RFID tags would be left at<br>
>>> Noisebridge. You grab an RFID tag on your way out, and it would grant you<br>
>>> automatic reentry on your return. The hardware for such a system would be<br>
>>> VERY simple; something like this:<br>
>>> <a href="http://www.makershed.com/ProductDetails.asp?ProductCode=MKPX2" target="_blank">http://www.makershed.com/ProductDetails.asp?ProductCode=MKPX2</a> with a<br>
>>> microcontroller and a relay.<br>
>>><br>
>>> The question is, would Noisebridge cover the cost of the RFID tags? They<br>
>>> run from $1.50 to $5 each depending on what kind of chip they use (Hitag<br>
>>> would be nice so it would work with my implant). If so, I'd be very happy<br>
>>> to help with the project.<br>
>>><br>
>>> Blaine<br>
><br>
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<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>Mark Cohen</div><div><a href="mailto:markc@binaryfaith.com">markc@binaryfaith.com</a></div><div><br></div><div>Science is a way of skeptically interrogating the universe with a fine understanding of human fallibility.</div><div>-Carl Sagan, 1996</div></div></div></div>
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