webcam app to watch for and time stamp changes
Most two factor authentication systems have re-sync capability, rsa had thieir token master key compromised for all des based tokens I believe
Sent from my iPhone
On Mar 2, 2013, at 16:41, Jim Lux jimlux@earthlink.net wrote:
On 3/2/13 1:29 PM, lists@lazygranch.com wrote:
If you think about it, there would have to be some time correction if only because these fobs can't be all that accurate in maintaining time. That is, they would be no better than a watch.
I'm not so keen on wearing out the internal battery since these things are now $30 instead of $5 when paypal introduced them.
mine is on all the time..
http://en.wikipedia.org/wiki/File:SecureID_token_new.JPG
I presume the battery will die in some number of years <10
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On 03/03/2013 01:00 AM, Peter Gottlieb wrote:
Perhaps you can detect EMI from the device especially if you put it it a
shielded metal box with pickup antenna. You might be able to get the
clock right from that.
Well, considering that actively "driving" a LCD segment involves passing
an AC field over it, in electrostatic drive, you could detect the
existence of AC or not on a segment, but you would have to "mask out"
that of other segments. On the other hand, you can expect a multiplexed
drive. An E-field detector as such would be able to pick up the shifts.
Wonders if the multiplexing is done by the same clock or a free-running
clock. If it is the same clock, just picking up the E-field from the
multiplex suffice to detect the clock ticking.
Cheers,
Magnus
On 3/2/13 4:12 PM, Magnus Danielson wrote:
On 03/03/2013 01:00 AM, Peter Gottlieb wrote:
Perhaps you can detect EMI from the device especially if you put it it a
shielded metal box with pickup antenna. You might be able to get the
clock right from that.
Well, considering that actively "driving" a LCD segment involves passing
an AC field over it, in electrostatic drive, you could detect the
existence of AC or not on a segment, but you would have to "mask out"
that of other segments. On the other hand, you can expect a multiplexed
drive. An E-field detector as such would be able to pick up the shifts.
Wonders if the multiplexing is done by the same clock or a free-running
clock. If it is the same clock, just picking up the E-field from the
multiplex suffice to detect the clock ticking.
OH, ho.. this is clever.. Time to get the scope probe out.. Find the big
peak, work out a quick and dirty analog filter, run it to the counter...
I would suspect that the multiplexing comes off the same oscillator, the
whole thing probably runs off a 32 kHz clock crystal.
On 03/03/2013 01:39 AM, Jim Lux wrote:
On 3/2/13 4:12 PM, Magnus Danielson wrote:
On 03/03/2013 01:00 AM, Peter Gottlieb wrote:
Perhaps you can detect EMI from the device especially if you put it it a
shielded metal box with pickup antenna. You might be able to get the
clock right from that.
Well, considering that actively "driving" a LCD segment involves passing
an AC field over it, in electrostatic drive, you could detect the
existence of AC or not on a segment, but you would have to "mask out"
that of other segments. On the other hand, you can expect a multiplexed
drive. An E-field detector as such would be able to pick up the shifts.
Wonders if the multiplexing is done by the same clock or a free-running
clock. If it is the same clock, just picking up the E-field from the
multiplex suffice to detect the clock ticking.
OH, ho.. this is clever.. Time to get the scope probe out.. Find the big
peak, work out a quick and dirty analog filter, run it to the counter...
Thanks. It's physics applied, knowing the basics and work from there.
I would suspect that the multiplexing comes off the same oscillator, the
whole thing probably runs off a 32 kHz clock crystal.
Most probably. You would probably enjoy having a JFET amplifier in there.
Cheers,
Magnus
Well, considering that actively "driving" a LCD segment involves passing
an AC field over it, in electrostatic drive, you could detect the
existence of AC or not on a segment, but you would have to "mask out"
that of other segments. On the other hand, you can expect a multiplexed
drive. An E-field detector as such would be able to pick up the shifts.
Wonders if the multiplexing is done by the same clock or a free-running
clock. If it is the same clock, just picking up the E-field from the
multiplex suffice to detect the clock ticking.
Magnus,
That is indeed a clever idea. I'm sure the AC drive is derived from the same clock so if Jim can see the LCD segment/backplane waveform he's got a handle on the clock.
When playing with watches a while ago I tried to pick up any 32 kHz signal but failed. Those with 1 Hz stepper motors were easy, but LED or LCD displays were too electro/magnetic/acoustic quiet for me to ever detect anything.
Do you have suggestions on what sort of "antenna" to use to pick up the LCD AC E-field? I'd expect the LCD drive current to be vanishing small.
/tvb
Content-Type: text/plain; charset=ISO-8859-1
In message 657D7F7CC03849419A2A90752E6A60A6@pc52, "Tom Van Baak" writes:
When playing with watches a while ago I tried to pick up any 32
kHz signal but failed. Those with 1 Hz stepper motors were easy,
but LED or LCD displays were too electro/magnetic/acoustic quiet
for me to ever detect anything.
Most LCD and LED clocks have a shielding metal-coating on the front
glass, exactly to eliminate all EMI/EMC issues.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
On 03/03/2013 10:00 AM, Poul-Henning Kamp wrote:
Content-Type: text/plain; charset=ISO-8859-1
In message657D7F7CC03849419A2A90752E6A60A6@pc52, "Tom Van Baak" writes:
When playing with watches a while ago I tried to pick up any 32
kHz signal but failed. Those with 1 Hz stepper motors were easy,
but LED or LCD displays were too electro/magnetic/acoustic quiet
for me to ever detect anything.
Most LCD and LED clocks have a shielding metal-coating on the front
glass, exactly to eliminate all EMI/EMC issues.
Darn. I should have guessed.
Cheers,
Magnus
On 3/3/13 1:00 AM, Poul-Henning Kamp wrote:
Content-Type: text/plain; charset=ISO-8859-1
In message 657D7F7CC03849419A2A90752E6A60A6@pc52, "Tom Van Baak" writes:
When playing with watches a while ago I tried to pick up any 32
kHz signal but failed. Those with 1 Hz stepper motors were easy,
but LED or LCD displays were too electro/magnetic/acoustic quiet
for me to ever detect anything.
Most LCD and LED clocks have a shielding metal-coating on the front
glass, exactly to eliminate all EMI/EMC issues.
Yes, but perhaps there's enough leakage to make this work. After all,
the EMI requirement (assuming it's running at 32 kHz) isn't particularly
stringent and because the fob is small, the radiated field at any
distance is going to very small. OTOH, I can put a probe or coil right
on or around the fob.
I'll let you all know what I detect when I try it tomorrow.
On 03/03/2013 03:46 PM, Jim Lux wrote:
On 3/3/13 1:00 AM, Poul-Henning Kamp wrote:
Content-Type: text/plain; charset=ISO-8859-1
In message 657D7F7CC03849419A2A90752E6A60A6@pc52, "Tom Van Baak"
writes:
When playing with watches a while ago I tried to pick up any 32
kHz signal but failed. Those with 1 Hz stepper motors were easy,
but LED or LCD displays were too electro/magnetic/acoustic quiet
for me to ever detect anything.
Most LCD and LED clocks have a shielding metal-coating on the front
glass, exactly to eliminate all EMI/EMC issues.
Yes, but perhaps there's enough leakage to make this work. After all,
the EMI requirement (assuming it's running at 32 kHz) isn't particularly
stringent and because the fob is small, the radiated field at any
distance is going to very small. OTOH, I can put a probe or coil right
on or around the fob.
I'll let you all know what I detect when I try it tomorrow.
An electrostatic shield will not contain the H-field from the shifting
currents.
Cheers,
Magnus
On Sat, 02 Mar 2013 11:33:02 -0800, Jim Lux wrote:
I am interested in the timing behavior of my RSA fob, which changes
every 60 seconds. Since I'm not about to open it up and probe inside, I
was wondering if someone had a clever way, say using a USB web cam, to
log the changes over a 48 hour period. You'd point the web cam at the
fob, and it would log the time when the display changes Or one might
even be able to look at the blinking 1 pps indicator using a light and
photocell or something..
Isn't this "Just what the doctor ordered"
http://smallhacks.wordpress.com/2012/11/11/reading-codes-from-rsa-
secureid-token/
CFO