Re: Detectable cash notes a fantasy

2002-04-11 Thread Sampo Syreeni

On Wed, 10 Apr 2002, Tim May wrote:

>> How come? True, if a bill is idealized as being planar, you'll have
>> trouble on the plane. Spatial diversity will take care of that.
>> Otherwise, a common note has plenty of surface to do your thing on.
>> Especially at higher frequencies, like UHF and beyond.
>
>How come? Because I am assuming the transponders are in the same
>position on each bill.

Why's that? It's easy enough to move the transponder around during the
printing process as long as the exact position isn't too important and the
number of positions isn't too large. Just have a rotating series of
printing plates.

>If you want to posit some "spatial diversity" model, that helps, but not
>but a huge amount.

First, "spatial diversity" is standard terminology for
spatially/polarization-wise separated transmitters/receivers, used in
order to fight multipath and/or antenna orientation trouble. In closed
spaces, that sort of antenna configuration is probably what you'd want,
anyway.

>UHF is hard to launch/receive from a small, planar antenna. UWB is
>easier to launch from a small (< cm) antenna, but is usually too
>directional.

Who's there to say the antenna has to be A stack will interfere, in the sense that planar antennas will couple to
>each other (radiated signal from A will hit B square on, etc.).

So they will. Still, I'm not at all sure one couldn't avoid much of the
coupling by moving the antenna around in the bill. And if that's not
enough, just build in ad hoc networks. Not too difficult, not too
expensive once you've got silicon on-board. Note-to-note, then out.

>As for the proles being too cheap, too gullible to even bother to
>lightly shield, sounds like evolution in action.

Not really, given that shielding could be outlawed.

>True money launderers will use shielding. (Actually, this is all
>oriented at "walking around money," so the vast infrastructure will
>never actually get built, as there is no interest in monitoring trivial
>amounts.)

Who's to say the primary application would be anti-laundering? To me it
seems far more likely that low-cost surveillance would be It, even if it's
clear that that sort of thing isn't currently doable.

>I'm done with this thread, though.

Too bad. Trimming CC's.

Sampo Syreeni, aka decoy - mailto:[EMAIL PROTECTED], tel:+358-50-5756111
student/math+cs/helsinki university, http://www.iki.fi/~decoy/front
openpgp: 050985C2/025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2




Re: Detectable cash notes a fantasy

2002-04-11 Thread Sunder

On Thu, 11 Apr 2002, Eugen Leitl wrote:

> I could imagine airlines screening for this, though, as a big RFID splash
> would invite you to become a target for "random" searches, and a
> prospective target for confiscation.

Better yet, rather than nuke your rfids, try to extract them out of the
currency as money passes your hands and collect them.  Then place them in
some high government official's pocket when they aren't looking.




Re: Detectable cash notes a fantasy

2002-04-11 Thread Tim May

On Thursday, April 11, 2002, at 07:07  AM, Trei, Peter wrote:
> [1. Agreed, this thread has lost steam.
>  2. It always amazes me how often people on this list will handwave and
> speculate on subjects which a few minutes with Google will settle. Too
> often, we're like the medieval academics who debated endlessly over how
> many teeth a horse had, while refusing to go down to the stable to
> conduct an actual count. ]

I didn't handwave and speculate: I said that the detection and antenna 
problems are enormous. This is borne out by the FAQ you cited, but I 
didn't need that FAQ to confirm what the physics already tells us.

That FAQ does NOT support the claim that stacks of bills may be 
detected, even with a door-frame-size antenna.


--Tim May




RE: Detectable cash notes a fantasy

2002-04-11 Thread Trei, Peter

> --
> From: [EMAIL PROTECTED][SMTP:[EMAIL PROTECTED]]
> Sent: Thursday, April 11, 2002 11:24 AM
> To:   [EMAIL PROTECTED]
> Subject:  RE: Detectable cash notes a fantasy 
> 
> > Go and read 'Repent Harlequin! Cried the Tick-Tock Man' by PK Dick for a
> > particularly slackless society with this technology.
> 
> Might be easier to find if you substitute Harlan Ellison as the author,
> though.
> 
>  - Sten
> 
Mea culpa. It's been a long time since I read 'Dangerous Visions'.

peter




RE: Detectable cash notes a fantasy

2002-04-11 Thread thaning

> Go and read 'Repent Harlequin! Cried the Tick-Tock Man' by PK Dick for a
> particularly slackless society with this technology.

Might be easier to find if you substitute Harlan Ellison as the author, though.

 - Sten




RE: Detectable cash notes a fantasy

2002-04-11 Thread Trei, Peter

> Eugen Leitl[SMTP:[EMAIL PROTECTED]] wrote:
> 
> Remember that original issue was reading the embedded RFID in a stack of
> bills from across the room with a portable reader. A possibly shielded
> stack of bills.
> 
> The FAQ you cited says 60 RFID tags/s reader speed under optimal
> consitions (I presume a bunch of naked RFID tags within cm of the reader)
> 
> is impressive, though. I don't see Hitachi tags discussed below, however.
> And those are 0.4 mm^2, 2.45 GHz.
> 
> http://www.hitachi.com/products/material/rfid/rfidprods/index.html says 
> communication distance near-contact (1 cm) for on-chip antenna (the only 
> one useful for in-paper embedding), and 25 cm (potentially up to 1 m), 
> which pretty much settles even the favourable doorframe issue.
> 
I agree, for the moment. I'm more worried about where this
technology will be five or ten years down the road.

> > ... and run into trouble from salesdroids who won't accept them.
> 
> Acting dumb (hey, if it looks like cash, it is cash) helps. And if there's
> no backpressures, before long you'll find yourself strutting down the
> street sprouting an antenna behind the ear, for the teledetonable
> implanted cranial explosive (saves on law reinforcement), and a king-size
> anal probe to boot.
> 
Go and read 'Repent Harlequin! Cried the Tick-Tock Man' by PK Dick for a
particularly slackless society with this technology.

Peter




RE: Detectable cash notes a fantasy

2002-04-11 Thread Eugen Leitl

On Thu, 11 Apr 2002, Trei, Peter wrote:

>  2. It always amazes me how often people on this list will handwave and
> speculate on subjects which a few minutes with Google will settle. Too

I prefer physics to Google any time to settle an issue. Physics and Google 
would seem to disagree on Digital Angel, for instance.

> often, we're like the medieval academics who debated endlessly over how
> many teeth a horse had, while refusing to go down to the stable to
> conduct an actual count. ]

Remember that original issue was reading the embedded RFID in a stack of
bills from across the room with a portable reader. A possibly shielded
stack of bills.

The FAQ you cited says 60 RFID tags/s reader speed under optimal
consitions (I presume a bunch of naked RFID tags within cm of the reader)  
is impressive, though. I don't see Hitachi tags discussed below, however.
And those are 0.4 mm^2, 2.45 GHz.

http://www.hitachi.com/products/material/rfid/rfidprods/index.html says 
communication distance near-contact (1 cm) for on-chip antenna (the only 
one useful for in-paper embedding), and 25 cm (potentially up to 1 m), 
which pretty much settles even the favourable doorframe issue.

Google this, kemo sabe.

> ... and run into trouble from salesdroids who won't accept them.

Acting dumb (hey, if it looks like cash, it is cash) helps. And if there's
no backpressures, before long you'll find yourself strutting down the
street sprouting an antenna behind the ear, for the teledetonable
implanted cranial explosive (saves on law reinforcement), and a king-size
anal probe to boot.




RE: Detectable cash notes a fantasy

2002-04-11 Thread Trei, Peter

> Eugen Leitl[SMTP:[EMAIL PROTECTED]]
> 
> 
> On Wed, 10 Apr 2002, Tim May wrote:
> 
> > How come? Because I am assuming the transponders are in the same
> > position on each bill. If you want to posit some "spatial diversity"  
> > model, that helps, but not but a huge amount. This sounds too science
> > fictionish to actually deploy (transponders are not the same as
> > letters, and cannot be moved around on a random basis).
> 
> The RFIDs are small enough to be able to positioned randomly within the
> fabric of the bill, but it still doesn't help if they yell in unison
> (something much less problematic with ultrawideband, admittedly).  Phased
> array is sure nice, but homing in on a cloud of weak emitters with cm
> spatial jitter doesn't sound viable. Doorway antennas should be able to
> pickup a RFID-tagged cash signature relatively easily, though, though it
> won't be able to pick up the ID of each individual bill in a stack, unless
> 
> you're willing to stand in that (shielded) doorway for a long time.
>  
[...]
[1. Agreed, this thread has lost steam. 
 2. It always amazes me how often people on this list will handwave and
speculate on subjects which a few minutes with Google will settle. Too
often, we're like the medieval academics who debated endlessly over how
many teeth a horse had, while refusing to go down to the stable to
conduct an actual count. ]

I refer you to the TI RFID FAQ, at 
http://www.ti.com/tiris/docs/customerService/faq.htm
to quote:-
4) What is the minimum separation between Tags?

There is no minimum separation between tags. Using the SID
(anti-collision algorithm), multiple tags close to the antenna can be
readily identified but if they are at the extreme reading range, they will
require some separation (5 cm) to prevent mutual de-tuning. If
individual tags are passing an antenna, some separation will need to
be maintained if the anti-collision algorithm is not being used. The
separation is related to the size of the reading zone and should be
sufficient that only one tag is in the field at one time.

5) How many Tags can be identified?

Using anti-collision techniques, there is theoretically no limit to the
number of tags that could be inventoried at one time. Although, in the
real world this is dependant on a number of factors:

1. The size of the reader's antenna
2. RF Power 
3. How closely packed the tags are
4. How long you are prepared to wait for the data

It requires a strong RF field for simultaneous identification, as tightly
packed tags can 'soak up' the power and possibly de-tune each other
if they are too close together. Smaller antennas have stronger RF
fields close to the antenna, whereas a larger antenna, capable of
reading more tags, and may have a less dense RF field.

Using simultaneous identification, around 30 tags/ sec can be
inventoried. If you wish to read extra data, the time required will
increase, e.g. to inventory 20 tags and return one page of information
from each, takes 1 second.

Without simultaneous ID, up to 60 individual tags can be read in one
second. 

-end of quote ---

> Righto. By the time EU will be tagging banknotes (and only bigger ones)  
> I'm very ready to crush and/or nuke the RFID tags in the microwave.
> 
... and run into trouble from salesdroids who won't accept them.

[...]

Peter Trei




Re: Detectable cash notes a fantasy

2002-04-11 Thread Eugen Leitl

On Wed, 10 Apr 2002, Tim May wrote:

> How come? Because I am assuming the transponders are in the same
> position on each bill. If you want to posit some "spatial diversity"  
> model, that helps, but not but a huge amount. This sounds too science
> fictionish to actually deploy (transponders are not the same as
> letters, and cannot be moved around on a random basis).

The RFIDs are small enough to be able to positioned randomly within the
fabric of the bill, but it still doesn't help if they yell in unison
(something much less problematic with ultrawideband, admittedly).  Phased
array is sure nice, but homing in on a cloud of weak emitters with cm
spatial jitter doesn't sound viable. Doorway antennas should be able to
pickup a RFID-tagged cash signature relatively easily, though, though it
won't be able to pick up the ID of each individual bill in a stack, unless 
you're willing to stand in that (shielded) doorway for a long time.
 
> UHF is hard to launch/receive from a small, planar antenna. UWB is 
> easier to launch from a small (< cm) antenna, but is usually too 
> directional.

UWB packs considerable punch in very short pulses, so one obviously needs 
a capacitor, as the passive power is much too weak to drive it directly. 
Nice thing about UWB is intrinsic collision avoidance due to PRNG timing 
of individual pulses.
 
> As for the proles being too cheap, too gullible to even bother to
> lightly shield, sounds like evolution in action.

Righto. By the time EU will be tagging banknotes (and only bigger ones)  
I'm very ready to crush and/or nuke the RFID tags in the microwave.
 
> Actually, more to the point, it means that the vast infrastructure of
> "remote bill readers" will, perforce, pick up the proles. True money
> launderers will use shielding. (Actually, this is all oriented at
> "walking around money," so the vast infrastructure will never actually
> get built, as there is no interest in monitoring trivial amounts.)

I could imagine airlines screening for this, though, as a big RFID splash
would invite you to become a target for "random" searches, and a
prospective target for confiscation.
 
> I'm done with this thread, though.




Re: Detectable cash notes a fantasy

2002-04-11 Thread Faustine

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Tim wrote:
Faustine wrote:

> If, when I came here, I had made the deliberate choice to make an
> effort at "getting along" by emphasizing our similarities instead of
> differences, I dare say the motivation to dissect-and-destroy every last
> comment I ever make would be nonexistent.

>>You haven't contributed anything interesting that I can recall.

Oh of course not, heaven forfend. 


>> Even if you discount my comments, surely you must have noticed that rarely
>> do your posts generate significant follow-up. (Which is a small blessing.)

Who said generating a lot of follow-up was on my "to-do" list? Believe it or
not, I'm perfectly fine with contributing here and there when I can and
learning from everyone else when I can't. If I were as wrapped up in the
pecking order dynamic as you seem to be, I'd really be putting a lot more
effort into it.
 
But as it is--given how incredibly busy I am--if my peculiar little set
of toys is all I feel like bringing to share at sandbox right now,
what concern is it of yours or anyone else's? Why not run along now and kick
some sand on one of your boring asskisser friends, shake things up a little...


>>Sometimes you natter about about (what) you think the RAND Corporation, your
>>apparent ideal, would do things,

Well is that a fact Grampy. Nattering about what interests me, alert the media.


> and sometimes you praise Herman Kahn 

Damn straight I do! Anyone interested in libertarian futurism really ought to
check him out if they haven't already--and I'm assuming this description
applies to quite a few people here...good starting links:

http://www.alteich.com/links/kahn.htm

I seem to remember your having a few kind words for a work or two of his
yourself--so I do hope you won't go running down a great man just for the sake
of getting at me.


>and other O.R. types. 

Hooey. 


> But you have nothing significant to contribute about anything closely related
> to list themes.

There you go again, defining what's acceptable for people what to talk about.
Anyway, as always, it's not what you say or don't say on a list, its what you
do. In the abstract, it would be kind of useful to talk to you about it, but in
practice that's not really an option. A shame, really.

>You should think about some of the real issues and come up with some 
>kind of incisive analysis or creative proposal

As should we all. Fair enough, but I've written plenty I haven't felt like
posting here for a number of reasons. Maybe I will, maybe not, who cares.
Even if I left it to others to post "significant" ideas it hardly matters.


>even Choate is more on-topic than you've been. 

You know, I like arguing with Choate: too bad you pissed him off to the point
he feels the need to post newslinks all the time. Did you catch how he didn't
start up again until you said you "quieted him down" or whatever it was? 
Thanks a lot.


>The lectures from you about how we're a bunch of untrained amateurs are
>getting old.

Oh come on, that's all in your head. Like you're one to talk about being
condescending about what people know and dont know! Pot, kettle, look in
the mirror.


Looking forward to your next significant post,

~~Faustine.


***

"If you don't like 'em, ignore them or filter them. That's
the Cypherpunk way of doing things."

Tim May, on the Cypherpunks list, 1995

-BEGIN PGP SIGNATURE-
Version: PGPsdk version 1.7.1 (C) 1997-1999 Network Associates, Inc. and its 
affiliated companies. (Diffie-Helman/DSS-only version)

iQA/AwUBPLUJAfg5Tuca7bfvEQLdegCg+S2sDHGzsGOTBVPNMf9x8Bn3NWQAoOpF
KG4JNBT8BOO+tK0+wjp6qVwn
=tFxE
-END PGP SIGNATURE-




Re: Detectable cash notes a fantasy

2002-04-10 Thread Tim May

On Wednesday, April 10, 2002, at 11:58  AM, Faustine wrote:
> If, when I came here, I had made the deliberate choice to make an 
> effort at
> "getting along" by emphasizing our similarities instead of differences, 
> I dare
> say the motivation to dissect-and-destroy every last comment I ever 
> make would
> be nonexistent.

You haven't contributed anything interesting that I can recall. Even if 
you discount my comments, surely you must have noticed that rarely do 
your posts generate significant follow-up. (Which is a small blessing.)

Sometimes you natter about about you think the RAND Corporation, your 
apparent ideal, would do things, and sometimes you praise Herman Kahn 
and other O.R. types. But you have nothing significant to contribute 
about anything closely related to list themes.

>
You should think about some of the real issues and come up with some 
kind of incisive analysis or creative proposal--even Choate is more 
on-topic than you've been. The lectures from you about how we're a bunch 
of untrained amateurs are getting old.


--Tim May
"Dogs can't conceive of a group of cats without an alpha cat." --David 
Honig, on the Cypherpunks list, 2001-11




RE: Detectable cash notes a fantasy

2002-04-10 Thread Jonathan Wienke

30 seconds in a microwave on high, stir and rotate tray...

-Original Message-
From: Michael Motyka [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, April 10, 2002 8:24 AM
To: [EMAIL PROTECTED]
Subject: Re: Detectable cash notes a fantasy 


Tim May <[EMAIL PROTECTED]> 
>
>On Tuesday, April 9, 2002, at 10:54  AM, Trei, Peter wrote:
>> Putting RF Tags in cash is one of those ideas with Unintended 
>> Consequences.
>> Muggers would love having a way of determining which victims are 
>> carrying a
>> wad, as would many salesmen (and JBTs looking to perform a 'civil
>> confiscation' on 'a sum of currency'.)
>
>Physics-wise, it's a jiveass fantasy. No way are there "micro-strips" 
>readable from a distance in today's currency, and very likely not in the 
>next 20 years. (I don't dispute that a careful lab setup could maybe 
>read a note at a few meters, in a properly-shielded environment, without 
>any shieding between note and detectors, and with enough time and 
>tuning. But a wad of bills, folded, stuffed, and with little time to 
>make the detection...an altogether different kettle of fish.)
>
>Further, placing the notes in a simple aluminum foil pouch, or a wallet 
>with equivalent lining, would cut any detectable signals by maybe 30-50 
>dB.
>
Or more. 

Not to mention that if you didn't want your money chirping its presence
every time a bad actor pinged it you could just disable the transponder
in the money : 

mechanical pressure or repeated bending
high voltage
high power RF
heat

For paper money failure rates will probably be high anyway.

>--Tim May
>

I'm guessing that electronic tracking or outright elimination of cash
would be coupled with a surge in the use of barter and alternative
monies.

Mike




Re: Detectable cash notes a fantasy

2002-04-10 Thread Tim May

On Wednesday, April 10, 2002, at 12:25  PM, Sampo Syreeni wrote:

> On Wed, 10 Apr 2002, Tim May wrote:
>> (A stack of bills, or cards, will have extremely poor radiation 
>> patterns
>> from any but the top or bottom bill, and probably their patterns won't
>> be good either.)
>
> How come? True, if a bill is idealized as being planar, you'll have
> trouble on the plane. Spatial diversity will take care of that. 
> Otherwise,
> a common note has plenty of surface to do your thing on. Especially at
> higher frequencies, like UHF and beyond.

How come? Because I am assuming the transponders are in the same 
position on each bill. If you want to posit some "spatial diversity" 
model, that helps, but not but a huge amount. This sounds too science 
fictionish to actually deploy (transponders are not the same as letters, 
and cannot be moved around on a random basis).

UHF is hard to launch/receive from a small, planar antenna. UWB is 
easier to launch from a small (< cm) antenna, but is usually too 
directional.

A stack will interfere, in the sense that planar antennas will couple to 
each other (radiated signal from A will hit B square on, etc.).

As for the proles being too cheap, too gullible to even bother to 
lightly shield, sounds like evolution in action.

Actually, more to the point, it means that the vast infrastructure of 
"remote bill readers" will, perforce, pick up the proles. True money 
launderers will use shielding. (Actually, this is all oriented at 
"walking around money," so the vast infrastructure will never actually 
get built, as there is no interest in monitoring trivial amounts.)

I'm done with this thread, though.

--Tim May
"They played all kinds of games, kept the House in session all night, 
and it was a very complicated bill. Maybe a handful of staffers actually 
read it, but the bill definitely was not available to members before the 
vote." --Rep. Ron Paul, TX, on how few Congresscritters saw the 
USA-PATRIOT Bill before voting overwhelmingly to impose a police state




Re: Detectable cash notes a fantasy

2002-04-10 Thread Sampo Syreeni

On Wed, 10 Apr 2002, Tim May wrote:

>A meter-sized antenna is not going to efficiently radiate
>sub-millimeter-sized waves.

But it does give you brutal directivity. If you're truly working with
sub-millimeter waves, you might be able to discriminate between individual
bills with a phased array this size.

Sampo Syreeni, aka decoy - mailto:[EMAIL PROTECTED], tel:+358-50-5756111
student/math+cs/helsinki university, http://www.iki.fi/~decoy/front
openpgp: 050985C2/025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2




Re: Detectable cash notes a fantasy

2002-04-10 Thread Sampo Syreeni

On Wed, 10 Apr 2002, Tim May wrote:

>So, if in fact we _are_ talking about each $20 bill having such a
>transponder, then why are our arguments about how easy it will be to
>shield against remote probing not valid?

Because the economics do not work. People simply aren't
knowledgeable/interested enough to actually shield their notes, even if
this would only imply buying a foil-shielded wallet. Especially if such
wallets are outlawed. (Yes, this is starting to sound like too much, even
if governments don't always behave rationally.)

>(A stack of bills, or cards, will have extremely poor radiation patterns
>from any but the top or bottom bill, and probably their patterns won't
>be good either.)

How come? True, if a bill is idealized as being planar, you'll have
trouble on the plane. Spatial diversity will take care of that. Otherwise,
a common note has plenty of surface to do your thing on. Especially at
higher frequencies, like UHF and beyond.

Sampo Syreeni, aka decoy - mailto:[EMAIL PROTECTED], tel:+358-50-5756111
student/math+cs/helsinki university, http://www.iki.fi/~decoy/front
openpgp: 050985C2/025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2




Re: Detectable cash notes a fantasy

2002-04-10 Thread Tim May

On Wednesday, April 10, 2002, at 11:22  AM, Trei, Peter wrote:
> Detection range turns out to be function of antenna size - the reader's
> antenna, not the one on the transponder. So if you have a big (eg,
> doorframe size) antenna, you can do a lot better than the 'valid bill
> detector' on the countertop.

A meter-sized antenna is not going to efficiently radiate 
sub-millimeter-sized waves.

--Tim May

"They played all kinds of games, kept the House in session all night, 
and it was a very complicated bill. Maybe a handful of staffers actually 
read it, but the bill definitely was not available to members before the 
vote." --Rep. Ron Paul, TX, on how few Congresscritters saw the 
USA-PATRIOT Bill before voting overwhelmingly to impose a police state




Re: Detectable cash notes a fantasy

2002-04-10 Thread Adam Shostack

On Wed, Apr 10, 2002 at 10:59:32AM -0700, Tim May wrote:
| On Wednesday, April 10, 2002, at 09:27  AM, Trei, Peter wrote:
| >> For paper money failure rates will probably be high anyway.

| So, if in fact we _are_ talking about each $20 bill having such a 
| transponder, then why are our arguments about how easy it will be to 
| shield against remote probing not valid? Put the money in a foil packet, 
| or fold it over, or carry it in a stack, or in a standard metal 
| briefcase, and I _guarantee_ that detecting it from afar will be 
| extremely difficult.
| 
| If a stack of bills containing these transponders are supposed to be 
| read from afar, way beyond what a "valid bill detector" is likely to be 
| engineered to do, I'd like to see the physics worked out.
| 
| (A stack of bills, or cards, will have extremely poor radiation patterns 
| from any but the top or bottom bill, and probably their patterns won't 
| be good either.)

Does it matter?  Intuitively, you broadcast a radio signal, and pick
up from that where the largest clusters of bills are.  Repeat several
times if needed.  You don't care about signal accuracy, just
magnitude.  You then decide if the people with wads of cash look like
an easy mugging target.

Adam



-- 
"It is seldom that liberty of any kind is lost all at once."
   -Hume




Re: Detectable cash notes a fantasy

2002-04-10 Thread Tim May

On Wednesday, April 10, 2002, at 11:22  AM, Trei, Peter wrote:
> The argument against shielding is that it is obnoxious that I
> (or anyone) should have to go even further than I already do to
> maintain even a fraction of the privacy which was naturally available to
> every person 150 years ago.

Not to sound too much like Brin, but there was actually very _little_ 
privacy 150 years ago. Everyone knew who was buying what. Small towns 
and small neighborhoods. But I digresss...

Shielding is much easier than you think, unless shielding is outlawed.
>
> Folding the bill won't make any difference. stacking them might make
> a small difference, if the chips are close enough to detune each other.
> Some transponders (not the mu-tag, AFAIK) include anti-collision
> techniques, so many can be detected simultaneously.

The anticollision features are in the code, not the antennas. Stacking 
flat antennas on top of either other is _guaranteed_ to cut the output 
of any of the inner antennas (and probably the edge antennas) by many, 
many dB.

--Tim May
"A complex system that works is invariably found to have evolved from a
simple system that worked ...A complex system designed from scratch 
never  works and cannot be patched up to make it work. You have to start 
over,  beginning with a working simple system." -- Grady Booch




Re: Detectable cash notes a fantasy

2002-04-10 Thread Adam Shostack

On Wed, Apr 10, 2002 at 02:22:04PM -0400, Trei, Peter wrote:

| > If a stack of bills containing these transponders are supposed to be 
| > read from afar, way beyond what a "valid bill detector" is likely to be 
| > engineered to do, I'd like to see the physics worked out.
| > 
| Detection range turns out to be function of antenna size - the reader's
| antenna, not the one on the transponder. So if you have a big (eg, 
| doorframe size) antenna, you can do a lot better than the 'valid bill
| detector' on the countertop. There's actually a privacy win here for
| the passive tags - the returned signal strength falls with the fourth
| power of the distance.

Interesting.  What does that work out to for, say, a 2 meter antenna?
(I'm not sure if this actually works out to a security win.  It may be 
that I can use this fast fall-off to ensure that I'm picking the right 
pocket..)



Adam



-- 
"It is seldom that liberty of any kind is lost all at once."
   -Hume




Re: Detectable cash notes a fantasy

2002-04-10 Thread Faustine

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Tim wrote:

>Everytime I comment on your citations, you go into a snit about how 
>"Gramps" is insulting the "whippersnappers."

No, it's all about the condescending tone you take when you use "your many
years of experience" as leverage against anyone who rejects their place in
your pecking order.

Whether you choose to admit it or not, you're incredibly easygoing on people
here who kiss your ass, flatter you, and never dare contradict you out of a
fear of retribution. Like the example from a few months ago when you related
how somebody asked you if it would be okay to post certain kinds of articles
to the group. Why does this please you--don't you want your friends and
compatriots to have a fucking backbone? You think you're the only one here 
who gets to have a spine? Which isn't to say that if the group is set up a
certain way, it's right to be inconsiderate of what most people want and 
expect: for instance, I stopped posting links to news articles when it was 
made plain to me that most people found it an annoyance. But it wasn't because
anyone bullied me "into line". 

If, when I came here, I had made the deliberate choice to make an effort at
"getting along" by emphasizing our similarities instead of differences, I dare
say the motivation to dissect-and-destroy every last comment I ever make would
be nonexistent.

But then, how interesting would that be. 
 

>For all I know, in Real Life you're older than me, or you're some guy
>working a guard job at Lockheed. Or both. 

Ironically enough--but not that it matters--I haven't manufactured any of the
details about myself I've given here. I suppose the prudent thing to do would
be to encourage people to assume I'm a man (as if I'd have to do anything
besides take a neutral nym!) and keep you all looking for the old Lockheed
fart, etc. But I suppose it must the grandiosity or vanity or something that
compels me to vent under the guise of myself. Which is a pretty funny way to
put it actually, since what I say here is far more "real" than what most
people see of me in the "real world" in a lifetime. Which is probably part of
the point anyway. Not that I've given anyone the slightest reason to believe
a word of it, but there it is.
 
Yeah yeah, I know--"go tell it to Oprah".


>Or you may be the grad student at Hoboken State College you appear to be. 

A slur, eh? Not bad. I suspect you're being a little disingenuous though.
(If I really were at Hoboken, where's the sting in it?) Ah well, think what you
want--I don't have anything to prove. Or shouldn't, anyway.


> Whatever, I know that your main method of argument is either a bunch of "Bah"
> comments followed with cites apropos of nothing you've dug up. Such as your
> refutation of category theory by digging up some of the usual computer vision
> and scene analysis junk that's been going around for 40 years.

I did no such thing! You asked what happened to general systems theory and
expressed a negative view of OR that, though entirely warranted thirty years
ago, isn't true of what some people are doing today. So I gave a couple of
cites to papers that show how these concepts have been evolving, I thought you
might enjoy them. Entirely tangential to the main point of your post, but it's
new and it's not junk, damn it. If it's not interesting to you, fine-- but
there certainly wasn't any criticism of anything related to you somehow hidden
in it.


>I stand by my comment that shielding a thread in a $100 bill, for 
>example, is vastly easier than detecting it. Your cites about WiFi 
>frequencies and 3 meter ranges and suchlike don't mean much.


No of course not, since they were only meant to give a sense of the volume of
related research people are doing--hence my only point that 20 years seems a 
little generous. 

 
~~Faustine.




***

He that would make his own liberty secure must guard even his enemy from
oppression; for if he violates this duty he establishes a precedent that
will reach to himself.

- --Thomas Paine

-BEGIN PGP SIGNATURE-
Version: PGPsdk version 1.7.1 (C) 1997-1999 Network Associates, Inc. and its 
affiliated companies. (Diffie-Helman/DSS-only version)

iQA/AwUBPLSLY/g5Tuca7bfvEQLGigCeOjRDe4ApAZLoTIuGFWxdi/pVTTwAnjjx
aObuLmF9JjD+8oGJj2Y2zBoX
=lfHT
-END PGP SIGNATURE-




RE: Detectable cash notes a fantasy

2002-04-10 Thread Trei, Peter

> --
> From: Tim May[SMTP:[EMAIL PROTECTED]]
> Sent: Wednesday, April 10, 2002 1:59 PM
> To:   [EMAIL PROTECTED]
> Subject:  Re: Detectable cash notes a fantasy 
> 
> On Wednesday, April 10, 2002, at 09:27  AM, Trei, Peter wrote:
> >> For paper money failure rates will probably be high anyway.
> > Perhaps, perhaps not. Remember, the primary app for this is
> > anti-counterfeiting.
> > "Sir: ALL your $20 bills are failing authentication. Please wait
> > while I call Security."
> 
> So, if in fact we _are_ talking about each $20 bill having such a 
> transponder, then why are our arguments about how easy it will be to 
> shield against remote probing not valid? Put the money in a foil packet, 
> or fold it over, or carry it in a stack, or in a standard metal 
> briefcase, and I _guarantee_ that detecting it from afar will be 
> extremely difficult.
> 
The argument against shielding is that it is obnoxious that I
(or anyone) should have to go even further than I already do to
maintain even a fraction of the privacy which was naturally available to
every person 150 years ago.

Folding the bill won't make any difference. stacking them might make
a small difference, if the chips are close enough to detune each other. 
Some transponders (not the mu-tag, AFAIK) include anti-collision
techniques, so many can be detected simultaneously.

> If a stack of bills containing these transponders are supposed to be 
> read from afar, way beyond what a "valid bill detector" is likely to be 
> engineered to do, I'd like to see the physics worked out.
> 
Detection range turns out to be function of antenna size - the reader's
antenna, not the one on the transponder. So if you have a big (eg, 
doorframe size) antenna, you can do a lot better than the 'valid bill
detector' on the countertop. There's actually a privacy win here for
the passive tags - the returned signal strength falls with the fourth
power of the distance.

> (A stack of bills, or cards, will have extremely poor radiation patterns 
> from any but the top or bottom bill, and probably their patterns won't 
> be good either.)
> 
There's a basic faq at
http://www.ti.com/tiris/docs/customerService/faq.htm

> --Tim May
> 
Peter




Re: Detectable cash notes a fantasy

2002-04-10 Thread Sampo Syreeni

On Wed, 10 Apr 2002, Tim May wrote:

>The engineers of such SmartWallets will not give them more range than
>the protocol needs. Extra range costs money. If Alice is expected to
>insert her Smart Wallet into a receptacle (for security, if for nothing
>else), initiating the protocol from several meters away is not in the
>cards, so to speak.

Of course. But when you think of such applications as NID cards, it's
likely range is within the spec. Yes, NID's are suspicious enough as they
stand. No, people don't see this. Especially after services (or
"services", it doesn't seem to matter much) start being bound to them
 -- this is the way Finland, Estonia and a couple of other countries are
going, right now, with their electronic ID's.

>If someone is arguing that such Smart Wallets will merely be passive
>"announcers" of bank balances, this is just too naive to waste
>discussion time on. Good luck selling such a system.

Quite. Passive announcers of identity (or signers) with a secondary,
"enabled" mode for actually signing something legally binding, on the
other hand...

Sampo Syreeni, aka decoy - mailto:[EMAIL PROTECTED], tel:+358-50-5756111
student/math+cs/helsinki university, http://www.iki.fi/~decoy/front
openpgp: 050985C2/025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2




Re: Detectable cash notes a fantasy

2002-04-10 Thread Tim May

On Wednesday, April 10, 2002, at 09:27  AM, Trei, Peter wrote:
>> For paper money failure rates will probably be high anyway.
>>
>>
> Perhaps, perhaps not. Remember, the primary app for this is
> anti-counterfeiting.
>
> "Sir: ALL your $20 bills are failing authentication. Please wait
> while I call Security."
>

So, if in fact we _are_ talking about each $20 bill having such a 
transponder, then why are our arguments about how easy it will be to 
shield against remote probing not valid? Put the money in a foil packet, 
or fold it over, or carry it in a stack, or in a standard metal 
briefcase, and I _guarantee_ that detecting it from afar will be 
extremely difficult.

If a stack of bills containing these transponders are supposed to be 
read from afar, way beyond what a "valid bill detector" is likely to be 
engineered to do, I'd like to see the physics worked out.

(A stack of bills, or cards, will have extremely poor radiation patterns 
from any but the top or bottom bill, and probably their patterns won't 
be good either.)



--Tim May
"Extremism in the pursuit of liberty is no vice."--Barry Goldwater




Re: Detectable cash notes a fantasy

2002-04-10 Thread Tim May

On Wednesday, April 10, 2002, at 07:44  AM, Trei, Peter wrote:
> Tim: I advise you to get up to speed on this stuff.

I think I'm more up to speed on small detectors than I want to be 
(through my involvement with an ultrawideband company).

But I misunderstood the discussions about currency being tagged vs. 
wallets with transponders. (Which I don't see Joe Sixpack ever adopting 
in our lifetimes, for multiple of the usual reasons.)
>

>> Further, placing the notes in a simple aluminum foil pouch, or a wallet
>> with equivalent lining, would cut any detectable signals by maybe 30-50
>> dB.
>>
> Most people don't, and won't do this. You may not worry about the 
> sheeple,
> but I do.
>

I figure the sheeple will mostly take of themselves. And, in fact, they 
do, through a kind of collective recoiling from certain things, coupled 
with monkeywrenching, deliberate misuse, etc.

The "interesting" part of the space of uses of digital money is 
certainly, for me at least, not in the "wallets with transponders so 
that Big Brother can track your cash."

Selective disclosure of information (SDI) and all that stuff.

If wallets carry RF ZKIPS communication capabilities, as they probably 
will, the designed range will be small. And the wallet will probably 
have to be "enabled."

What I would picture is something like this: Alice approaches a kiosk or 
transfer point of some sort. She pulls out her SmartWallet (TM), enters 
a PIN or fingerprint, which turns on the device for some number of 
seconds, aims it at (or actually inserts it into) a receiver, and a 
ZKIPS protocol begins firing back and forth.

(Some here have said the Hitachi tags are passive. Fine. Useful for 
things like tracking railroad boxcars or shipping containers, where 
attaching a battery would be more expensive, less reliable, and too much 
work. But for a smart card or Smart Wallet, there will be active 
processing _anyway_ (as the account balance changes, as PINs are 
entered, etc.), so having a small battery, perhaps 
light-rechargeable (*), is OK. (* Smart cards already have this. I have 
a thin credit card calculator from the early 80s that works this way.)

And as in that standard example of "capabilities," she doesn't say 
"please look inside my wallet and take what you need." Rather, she 
authorizes a specific amount or limit (she extends a capability right, 
rather than an access right).

The engineers of such SmartWallets will not give them more range than 
the protocol needs. Extra range costs money. If Alice is expected to 
insert her Smart Wallet into a receptacle (for security, if for nothing 
else), initiating the protocol from several meters away is not in the 
cards, so to speak.

If someone is arguing that such Smart Wallets will merely be passive 
"announcers" of bank balances, this is just too naive to waste 
discussion time on. Good luck selling such a system.


--Tim May
"That the said Constitution shall never be construed to authorize 
Congress to infringe the just liberty of the press or the rights of 
conscience; or to prevent the people of the United States who are 
peaceable citizens from keeping their own arms." --Samuel Adams




Re: Detectable cash notes a fantasy

2002-04-10 Thread Tim May

On Wednesday, April 10, 2002, at 08:23  AM, Michael Motyka wrote:

> Or more.
>
> Not to mention that if you didn't want your money chirping its presence
> every time a bad actor pinged it you could just disable the transponder
> in the money :
>
> mechanical pressure or repeated bending
> high voltage
> high power RF
> heat
>
> For paper money failure rates will probably be high anyway.
>

As I said in another article, I think there'll be zero acceptance rate 
for any _general_ smartcard cash system which:

-- has no user-controlled on/off switch, or user authentication (PIN 
entry at minimum)
-- has a wide broadcast pattern
-- generally, has a "promiscuous" disclosure model

By "general" I mean a store of value to be used roughly as cash and 
credit cards are used today.

Specialized uses such as subway or bridge token systems may have 
different models. But they will likely also be:

-- limited in amount of money
-- linked to security protocols, e.g., only BART turnstile nominally has 
access
-- broadcast range and transponder physics tuned to specific use (e.g., 
BART turnstyle)

Now, of course, there may be calls by government for "back doors," for 
forced promiscuity, but this will complicate the engineering immensely. 
And shielding is still trivial.

I just don't see this as an interesting or fruitful discussion...maybe 
it's going to be the new version of the "Can I use thermite to destroy 
my data?" recurring thread.

--Tim May
"To those who scare peace-loving people with phantoms of lost liberty, 
my message is this: Your tactics only aid terrorists."  --John Ashcroft, 
U.S. Attorney General




Re: Detectable cash notes a fantasy

2002-04-10 Thread Michael Motyka

"Trei, Peter" wrote:
> 
> > Michael Motyka[SMTP:[EMAIL PROTECTED]]
> >
> >
> > Tim May <[EMAIL PROTECTED]>
> > >
> > >On Tuesday, April 9, 2002, at 10:54  AM, Trei, Peter wrote:
> > >> Putting RF Tags in cash is one of those ideas with Unintended
> > >> Consequences.
> > >> Muggers would love having a way of determining which victims are
> > >> carrying a
> > >> wad, as would many salesmen (and JBTs looking to perform a 'civil
> > >> confiscation' on 'a sum of currency'.)
> [...]
> > >
> > >Further, placing the notes in a simple aluminum foil pouch, or a wallet
> > >with equivalent lining, would cut any detectable signals by maybe 30-50
> > >dB.
> > >
> >
> >
> > Not to mention that if you didn't want your money chirping its presence
> > every time a bad actor pinged it you could just disable the transponder
> > in the money :
> >
> > mechanical pressure or repeated bending
> > high voltage
> > high power RF
> > heat
> >
> > For paper money failure rates will probably be high anyway.
> >
> >
> Perhaps, perhaps not. Remember, the primary app for this is
> anti-counterfeiting.
> 
> "Sir: ALL your $20 bills are failing authentication. Please wait
> while I call Security."
> 
> Peter
I thought of this but I felt that at this point it is no longer cash but
a fixed-denomination smart card. Currently you can exchange a partial
note ( > ~50% ) for a new one. There would have to be a mechanism in
place for failed electronic bills otherwise people might not be very
confident in accepting them. Granted, the inconvenience factor could get
high.

Mike




Re: Detectable cash notes a fantasy

2002-04-10 Thread Nomen Nescio

Tim May writes:
> I'll go back to lurking, as this "thread," so to speak, is not 
> interesting to me.
>
> (More interesting is reading Chris Hillman's page with his Categorical 
> Primer on it, http://www.math.washington.edu/~hillman/papers.html. And 
> to BL and JA, I downloaded O'CAML and picked up a couple of ML texts--I 

Go away.




RE: Detectable cash notes a fantasy

2002-04-10 Thread Trei, Peter

> Michael Motyka[SMTP:[EMAIL PROTECTED]]
> 
> 
> Tim May <[EMAIL PROTECTED]> 
> >
> >On Tuesday, April 9, 2002, at 10:54  AM, Trei, Peter wrote:
> >> Putting RF Tags in cash is one of those ideas with Unintended 
> >> Consequences.
> >> Muggers would love having a way of determining which victims are 
> >> carrying a
> >> wad, as would many salesmen (and JBTs looking to perform a 'civil
> >> confiscation' on 'a sum of currency'.)
[...]
> >
> >Further, placing the notes in a simple aluminum foil pouch, or a wallet 
> >with equivalent lining, would cut any detectable signals by maybe 30-50 
> >dB.
> >
> 
> 
> Not to mention that if you didn't want your money chirping its presence
> every time a bad actor pinged it you could just disable the transponder
> in the money : 
> 
> mechanical pressure or repeated bending
> high voltage
> high power RF
> heat
> 
> For paper money failure rates will probably be high anyway.
> 
> 
Perhaps, perhaps not. Remember, the primary app for this is
anti-counterfeiting.

"Sir: ALL your $20 bills are failing authentication. Please wait
while I call Security."

Peter




Re: Detectable cash notes a fantasy

2002-04-10 Thread Michael Motyka

Tim May <[EMAIL PROTECTED]> 
>
>On Tuesday, April 9, 2002, at 10:54  AM, Trei, Peter wrote:
>> Putting RF Tags in cash is one of those ideas with Unintended 
>> Consequences.
>> Muggers would love having a way of determining which victims are 
>> carrying a
>> wad, as would many salesmen (and JBTs looking to perform a 'civil
>> confiscation' on 'a sum of currency'.)
>
>Physics-wise, it's a jiveass fantasy. No way are there "micro-strips" 
>readable from a distance in today's currency, and very likely not in the 
>next 20 years. (I don't dispute that a careful lab setup could maybe 
>read a note at a few meters, in a properly-shielded environment, without 
>any shieding between note and detectors, and with enough time and 
>tuning. But a wad of bills, folded, stuffed, and with little time to 
>make the detection...an altogether different kettle of fish.)
>
>Further, placing the notes in a simple aluminum foil pouch, or a wallet 
>with equivalent lining, would cut any detectable signals by maybe 30-50 
>dB.
>
Or more. 

Not to mention that if you didn't want your money chirping its presence
every time a bad actor pinged it you could just disable the transponder
in the money : 

mechanical pressure or repeated bending
high voltage
high power RF
heat

For paper money failure rates will probably be high anyway.

>--Tim May
>

I'm guessing that electronic tracking or outright elimination of cash
would be coupled with a surge in the use of barter and alternative
monies.

Mike




RE: Detectable cash notes a fantasy

2002-04-10 Thread Mike Rosing

On Wed, 10 Apr 2002, Eugen Leitl wrote:

> The tags are passive. All tags (whether inductive or electrostatic) must 
> be energized from the outside. The pumping energy can be shielded, as can 
> the RF emission of the tags itself. The environment is noisy. The tags 
> send simultaneously from the same physical location.
> 
> I'm not sure whether microwave-pumped digital pulse radio based tags
> (currently no such technology officially exists) could have a somewhat
> wider range and less crosstalk, but even then they could be shielded.
> 
> On this background, the particular technology one uses is not very
> relevant, as we're talking about limits of physics. Reading secreted
> banknotes on your body with a magic wand reader is easy (unless wrapped in
> metal foil), reading them from across the room -- no, sir.

That's true for all RFID stuff, but the next generation the military is
looking at is called "smart dust".  The idea here is to have each speck
send info, and the conglomeration of specks adds up to a large signal
which can tell you something about the environment (like presense or
movement of large metal objects).  It's all sci-fi for now, and I think
they'll still have to power the things externally so the same shielding
applies, but if the bill holds enough transmitters it could have a
longer range.  But there's no reason a commercial object couldn't have
an off switch and power supply built in - the whole "wearable computer"
thing is aimed at that sort of application.

All we gotta do is prove to the wealthy they can get more wealthy, and we
get to play with the toys :-)

Patience, persistence, truth,
Dr. mike




RE: Detectable cash notes a fantasy

2002-04-10 Thread Eugen Leitl

On Wed, 10 Apr 2002, Trei, Peter wrote:

> So, yes, at the moment they can't scan your wallet very easily. But
> this technology is developing as all others are. I don't know about
> dealing with many similar tags more or less simultaneously, but some
> of the discussed apps for stock tracking require dealing with this
> problem.

The tags are passive. All tags (whether inductive or electrostatic) must 
be energized from the outside. The pumping energy can be shielded, as can 
the RF emission of the tags itself. The environment is noisy. The tags 
send simultaneously from the same physical location.

I'm not sure whether microwave-pumped digital pulse radio based tags
(currently no such technology officially exists) could have a somewhat
wider range and less crosstalk, but even then they could be shielded.

On this background, the particular technology one uses is not very
relevant, as we're talking about limits of physics. Reading secreted
banknotes on your body with a magic wand reader is easy (unless wrapped in
metal foil), reading them from across the room -- no, sir.




RE: Detectable cash notes a fantasy

2002-04-10 Thread Trei, Peter

> Tim May[SMTP:[EMAIL PROTECTED]]
> 
> On Tuesday, April 9, 2002, at 10:54  AM, Trei, Peter wrote:
> > Putting RF Tags in cash is one of those ideas with Unintended 
> > Consequences.
> > Muggers would love having a way of determining which victims are 
> > carrying a
> > wad, as would many salesmen (and JBTs looking to perform a 'civil
> > confiscation' on 'a sum of currency'.)
> 
> Physics-wise, it's a jiveass fantasy. No way are there "micro-strips" 
> readable from a distance in today's currency, and very likely not in the 
> next 20 years. (I don't dispute that a careful lab setup could maybe 
> read a note at a few meters, in a properly-shielded environment, without 
> any shieding between note and detectors, and with enough time and 
> tuning. But a wad of bills, folded, stuffed, and with little time to 
> make the detection...an altogether different kettle of fish.)
> 
Tim: I advise you to get up to speed on this stuff.

I don't recall anyone using the phrase 'micro-strips', which suggests you're
erroneously linking this discussion to the theory that there are detectors
for the anti-counterfeiting strips built into much modern currency. (FWIW,
the old British bills did use a metallic strip - if you scraped off the
paper
over it you could see the metal. US bills use a polymer strip).

We're discussing RFID tags, which are a bit different. In particular, the
mu-tag from Hitachi, which is 0.4 mm square, and 60-150 microns
thick, depending on version. You can see a picture at 

http://beta.kpix.com/news/local/2001/12/03/Tiny_Bay_Area_Invention_Could_Cha
nge_Security.html
(the chips are the things that look like iron filings)

There was a good article in the Economist a while back. If you're not a 
subscriber, it's reprinted (without a registration requirement) at 
http://www.cfo.com/article/1,5309,5867,00.html 

A presentation can be found at 
http://www.hitachi.com/products/electronic/semiconductorcomponent/elecrfid/e
lecrfidspecs/index.html

The version with the on-chip antenna has a range of about 1cm. The version
with an 
off-chip antenna has a range of 25cm (and possibly up to 1 meter). All it
does is
spit back a 128 bit number.

Most current applications appear to be for checking the authenticity of an
item in a
cooperative environment.

So, yes, at the moment they can't scan your wallet very easily. But this
technology
is developing as all others are. I don't know about dealing with many
similar tags
more or less simultaneously, but some of the discussed apps for stock
tracking
require dealing with this problem.

RFIDs are very scary from a privacy point of view, and very little attention

is being paid to them. Most are considerably heftier than the mu-chip, 
but they get cheaper and smaller every year. Mu-chips cost 10-15 cents.

> Further, placing the notes in a simple aluminum foil pouch, or a wallet 
> with equivalent lining, would cut any detectable signals by maybe 30-50 
> dB.
> 
Most people don't, and won't do this. You may not worry about the sheeple,
but I do.

> --Tim May
> 
Peter




Re: Detectable cash notes a fantasy

2002-04-10 Thread Tim May

On Tuesday, April 9, 2002, at 07:06  PM, Mike Rosing wrote:

> On Tue, 9 Apr 2002, Tim May wrote:
>
>> Physics-wise, it's a jiveass fantasy. No way are there "micro-strips"
>> readable from a distance in today's currency, and very likely not in 
>> the
>> next 20 years. (I don't dispute that a careful lab setup could maybe
>> read a note at a few meters, in a properly-shielded environment, 
>> without
>> any shieding between note and detectors, and with enough time and
>> tuning. But a wad of bills, folded, stuffed, and with little time to
>> make the detection...an altogether different kettle of fish.)
>>
>> Further, placing the notes in a simple aluminum foil pouch, or a wallet
>> with equivalent lining, would cut any detectable signals by maybe 30-50
>> dB.
>
> That solves the theives problem :-)  And you wouldn't need a wad, that's
> the whole point.  You'd just need 1.  It could transfer money just 
> like a
> smart card.

I must've missed the setup for this thread...I assumed the talk was of 
the standard "detector threads in our money" paranoia.

 From your description, it sounds like you're talking about a smart card 
variant. Why would it be set to "broadcast amount" or anything remotely 
like this? No smartcard protocol has this, nobody in their right mind 
would propose it as an interesting protocol (not even the Chaumian 
"untraceable road toll" transponders).  Smartcards or stored value 
wallets will obviously not be set, voluntarily or knowingly to broadcast 
their contents, nor to be interrogated by outsiders. Simple access 
control, ZKIPS, etc.

I'll go back to lurking, as this "thread," so to speak, is not 
interesting to me.

(More interesting is reading Chris Hillman's page with his Categorical 
Primer on it, http://www.math.washington.edu/~hillman/papers.html. And 
to BL and JA, I downloaded O'CAML and picked up a couple of ML texts--I 
sense a pun on Mac Lane in "ML for the Working Programmer." Just read 
Egan's "Quarantine," so the Hilbert vectors are coruscating tonight.)

A couple of last comments:

>
> But I'll grant it's science fiction at this point.  Maybe a smart card
> that has the weight of a gold coin with some thickness to it would work
> better.  For the filthy rich, make the outside real gold!  The rest of 
> us
> can use brass.
>
> I still think the basic problem is simple - how do you trust the bits?  
> If
> the actual computations are done inside a secure box, most people will
> trust it.  There will always be people who try to beat the system, but
> it'll take a lot of technology, and they'll do it often enough to get
> caught (most theives simply don't want to pass up a good deal when they
> invent one :-)  The actual structure of the box doesn't matter - a 
> floppy
> cloth bill or thick coin is still a computer.  Who makes and distributes
> it is what matters.
>
> Patience, persistence, truth,
> Dr. mike
>

Frankly, this is a remarkably naive level of understanding of digital 
money. Have you read any of Chaum's papers? Have you thought deeply 
about the issues?


--Tim May
"You don't expect governments to obey the law because of some higher 
moral development. You expect them to obey the law because they know 
that if they don't, those who aren't shot will be hanged." - -Michael 
Shirley




Re: Detectable cash notes a fantasy

2002-04-10 Thread Tim May

On Tuesday, April 9, 2002, at 07:43  PM, Faustine wrote:

> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
>
> Tim wrote:
>
>> Physics-wise, it's a jiveass fantasy. No way are there "micro-strips"
>> readable from a distance in today's currency, and very likely not in 
>> the
>> next 20 years.
>
> I'm not so sure it'll take that long, given the amount of effort people 
> are
> putting into it. Here are some relevant articles from that single 
> five-month
> old issue of Global ID Magazine I referenced...

Everytime I comment on your citations, you go into a snit about how 
"Gramps" is insulting the "whippersnappers."

For all I know, in Real Life you're older than me, or you're some guy 
working a guard job at Lockheed. Or both. Or you may be the grad student 
at Hoboken State College you appear to be. Whatever, I know that your 
main method of argument is either a bunch of "Bah" comments followed 
with cites apropos of nothing you've dug up. Such as your refutation of 
category theory by digging up some of the usual computer vision and 
scene analysis junk that's been going around for 40 year.

I stand by my comment that shielding a thread in a $100 bill, for 
example, is vastly easier than detecting it. Your cites about WiFi 
frequencies and 3 meter ranges and suchlike don't mean much.

  (As it happens, and you'll go into your "whippersnapper" rant for my 
mentioning names, but I'm an early investor in one of the leading 
ultrawideband (UWB) companies, one competing with the better-known Time 
Domain. Their antennas are launching high-current pulses in WiFi and 
even higher frequencies...the tagline is always "DC-to-daylight," of 
course, but 99% or so of the radiated power is in the .5-10 GHz band. I 
was up at their lab last Friday, checking on progress, walking around 
inside the cargo shipping container they've got set up at their place, 
and looking down on Skywalker Ranch below them. UWB may  turn out to be 
useful, but it has nothing to do with detecting threads embedded in Ben 
Franklins.)

> A long range ID system
> http://web.tiscali.it/homeglobal/issues/0111/Nov01-07.pdf
>
> Utilising the internationally approved 2.45Ghz UHF band allows 
> specialised
> readers to access the information contained in transponders at a 
> distance of up
> to three metres. Familiar sources of disturbance such as reflection, 
> noise
> interference and overreach have been eliminated by integrating UMTS/GSM
> technologies

--Tim May
"A democracy cannot exist as a permanent form of government. It can only 
exist until the voters discover that they can vote themselves money from 
the Public Treasury. From that moment on, the majority always votes for 
the candidate promising the most benefits from the Public Treasury with 
the result that a democracy always collapses over loose fiscal policy 
always followed by dictatorship." --Alexander Fraser Tyler




Re: Detectable cash notes a fantasy

2002-04-09 Thread Faustine

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

Tim wrote:

>Physics-wise, it's a jiveass fantasy. No way are there "micro-strips" 
>readable from a distance in today's currency, and very likely not in the 
>next 20 years. 

I'm not so sure it'll take that long, given the amount of effort people are
putting into it. Here are some relevant articles from that single five-month
old issue of Global ID Magazine I referenced...


A long range ID system
http://web.tiscali.it/homeglobal/issues/0111/Nov01-07.pdf

Utilising the internationally approved 2.45Ghz UHF band allows specialised
readers to access the information contained in transponders at a distance of up
to three metres. Familiar sources of disturbance such as reflection, noise
interference and overreach have been eliminated by integrating UMTS/GSM
technologies 


Miniaturising transponders
http://web.tiscali.it/homeglobal/issues/0111/Nov01-16.pdf

by Reihard Jurisch, Micro-Sensys
The consolidated techniques used for fabricating integrated circuits have been
successfully applied to the manufacturing of integrated transponders. Antenna
coils are micro-structured onto the chip containing the transponders 
electronic circuitry


Smart banknotes challenge conterfeiting
http://web.tiscali.it/homeglobal/issues/0111/Nov01-14.pdf

by Gaia Steden
Hitachi has developed its smallest RFID integrated circuit called the Mu
- -chip, which is thin enough to be embedded in paper.


Designer antennas for RFID applications
http://web.tiscali.it/homeglobal/issues/0111/Nov01-06.pdf

by Bob Scher, Dynasys
The choice of the correct RFID antenna for a specific application is a complex
issue. It is necessary to consider what elements of an RFID system are needed:
from the spacing of antennas to the strength, shape and resonance of readers 
and transponders


***

He that would make his own liberty secure must guard even his enemy from
oppression; for if he violates this duty he establishes a precedent that
will reach to himself.
- --Thomas Paine

-BEGIN PGP SIGNATURE-
Version: PGPsdk version 1.7.1 (C) 1997-1999 Network Associates, Inc. and its 
affiliated companies. (Diffie-Helman/DSS-only version)

iQA/AwUBPLOm2/g5Tuca7bfvEQJYWgCgmKncKA9rpBsIbiI7J3isPQ0pL5QAoPIC
4/1byzrcjsekyN/DxUi67mCE
=3OXb
-END PGP SIGNATURE-




Re: Detectable cash notes a fantasy

2002-04-09 Thread Mike Rosing

On Tue, 9 Apr 2002, Tim May wrote:

> Physics-wise, it's a jiveass fantasy. No way are there "micro-strips" 
> readable from a distance in today's currency, and very likely not in the 
> next 20 years. (I don't dispute that a careful lab setup could maybe 
> read a note at a few meters, in a properly-shielded environment, without 
> any shieding between note and detectors, and with enough time and 
> tuning. But a wad of bills, folded, stuffed, and with little time to 
> make the detection...an altogether different kettle of fish.)
> 
> Further, placing the notes in a simple aluminum foil pouch, or a wallet 
> with equivalent lining, would cut any detectable signals by maybe 30-50 
> dB.

That solves the theives problem :-)  And you wouldn't need a wad, that's
the whole point.  You'd just need 1.  It could transfer money just like a
smart card.

But I'll grant it's science fiction at this point.  Maybe a smart card
that has the weight of a gold coin with some thickness to it would work
better.  For the filthy rich, make the outside real gold!  The rest of us
can use brass.

I still think the basic problem is simple - how do you trust the bits?  If
the actual computations are done inside a secure box, most people will
trust it.  There will always be people who try to beat the system, but
it'll take a lot of technology, and they'll do it often enough to get
caught (most theives simply don't want to pass up a good deal when they
invent one :-)  The actual structure of the box doesn't matter - a floppy
cloth bill or thick coin is still a computer.  Who makes and distributes
it is what matters.

Patience, persistence, truth,
Dr. mike