In message , at 10:42:01 on Fri, 11 Mar
2011, d remarked:

There are different sots of security tag, just like there are different
sorts of "RFID" tag inside transport cards, or used for things like road
tolls. Much confusion arises when people assume these are all the same
technology.

Well I know there are different sorts - but that doesn't mean there isn't
a type thats RF powered. In fact the latest RFID tags are designed to be
powered up from a distance of a few feet and read.

I'm quite sure there will be battery-powered and RF-powered examples of
both retail security tags *and* transport cards.

But even that doesn't mean all the RF-powered ones will have the same
characteristics.
--
Roland Perry

On Thu, Mar 10, 2011 at 07:36:46PM -0000, tim.... wrote:
wrote in message
...
On Thu, 10 Mar 2011 17:00:36 -0000
"tim...." wrote:
Only of you wanted to fry the human holding it, at the same time
Why? It shouldn't need much more power than you'd get from those shop
security gates.
The security tags have an internal power source.

An awful lot of them don't. In fact an awful lot of them aren't active
devices at all, they simply resonate when exposed to particular
frequencies of magnetic field.

--
David Cantrell | top google result for "topless karaoke murders"

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On Fri, 11 Mar 2011 10:55:34 +0000
Roland Perry wrote:
But even that doesn't mean all the RF-powered ones will have the same
characteristics.

Well no. But that doesn't change my argument that its probably possible to
power up an Oyster card from a short distance away. After all, its been
alledged just this has been done with new biometric passports - not only
did they power them up by they read them too apparently from a few feet away.

B2003

In message , at 12:16:38 on Fri, 11 Mar
2011, d remarked:

But even that doesn't mean all the RF-powered ones will have the same
characteristics.

Well no. But that doesn't change my argument that its probably possible to
power up an Oyster card from a short distance away. After all, its been
alledged just this has been done with new biometric passports - not only
did they power them up by they read them too apparently from a few feet away.

sigh but that assumes the technologies of the Oyster and the Passport
are in any way comparable!

(Apart from anything else, the Passport has a much bigger aerial).
--
Roland Perry

On Fri, 11 Mar 2011 12:28:11 +0000
Roland Perry wrote:
Well no. But that doesn't change my argument that its probably possible to
power up an Oyster card from a short distance away. After all, its been
alledged just this has been done with new biometric passports - not only
did they power them up by they read them too apparently from a few feet away.

sigh but that assumes the technologies of the Oyster and the Passport
are in any way comparable!

In what way are they not comparable?

(Apart from anything else, the Passport has a much bigger aerial).

Fine. Whats the anything else?

B2003

wrote in message
...
On Thu, 10 Mar 2011 19:36:46 -0000
"tim...." wrote:
wrote in message
...
On Thu, 10 Mar 2011 17:00:36 -0000
"tim...." wrote:
Given a powerful enough directed RF signal you could certainly power
up
and
send signals to an Oyster card from a distance.

Only of you wanted to fry the human holding it, at the same time

Why? It shouldn't need much more power than you'd get from those shop
security gates.

The security tags have an internal power source.

You sure about that?

No. I just did a google and that is what I discovered

(OTOH I do know how RFID works without googling!)

tim

wrote in message
...
On Fri, 11 Mar 2011 10:55:34 +0000
Roland Perry wrote:
But even that doesn't mean all the RF-powered ones will have the same
characteristics.

Well no. But that doesn't change my argument that its probably possible to
power up an Oyster card from a short distance away. After all, its been
alledged just this has been done with new biometric passports - not only
did they power them up by they read them too apparently from a few feet
away.


I don't think they did.

The only reports that I have seen are from people eavesdropping when the
cards are powered up by a normal reader.

And then they "headline" their reports as being independently read from 5
meters away because that serves their political/commercial purpose, but if
you read very carefully it doesn't actually say that

tim

On Fri, 11 Mar 2011 13:00:25 -0000
"tim...." wrote:
I don't think they did.

The only reports that I have seen are from people eavesdropping when the
cards are powered up by a normal reader.

Thats worrying in itself.

And then they "headline" their reports as being independently read from 5
meters away because that serves their political/commercial purpose, but if
you read very carefully it doesn't actually say that

*shrug* Who knows.

Anyway , in my original post I merely said that I reckon its possible to
power up and read an Oyster card from a short distance. I didn't say anyone
had actually bothered to do it.

B2003