BT2 and Police

[imported_spankdidly]

I knew you'd say that.

LOL, I almost fell out of my chair reading that.

[Packets]

In the Mid 80's Wim van Eck was able to recreate the display from another computer at over 100 yards with $15 - $20 in electronic parts and an old television. I remember reading about it a little in the early 90's and wanting to experiment with it, but I was never able to find enough free information on it to create anything that would work.

This thread got me a little interested in the topic again. I was under the same impression as others that modern day flat screen monitors wouldn't be susceptible to this. However, after a little research it seems like there might still be some potential to achieve this from some emanations coming from the cables.

Regardless, interesting thread... Thanks for the good read.

[InSanCen]

While I agree with InSanCen that increases in areal density to provide slight hurdles to recovery I would also argue that the precision of the recovery and forensics tool is also increasing (microscopy etc). It's the same with everything in IT right? The attackers get better then the defenders get better, etc.... never ending repetition

And i would agree wholeheartedly. Modern Forensic Investigation is nothing short of a Miracle to joe public, and still pretty damn impressive to a jaded Tech like me.

I just meant to make the point that it is more than possible, as I do not like to see other people called out by someone with no proof and even less intelligence.

Looking forward to your rebuttal LinuxBeast

[phoenix910]

I'm also fully in agreeance with shamanvirtuel. I have also recovered data fully formatted multiple times, it's not like it's an impossible task. And the DoD standards of 3 or 7 times overwrite aren't for secure data erasure, that's just for everyday files - they delete their average things like that. So if that's not secure erasure, then they can obviously get that back. What's another three times gonna hurt?

And in terms of reading your screen from across the street - entirely possible with CRT monitors, but in terms of reading LCD monitors via cable emissions, I doubt that, because the shield cables (often with coaxial shielding) so that they don't pick up outside signals (which cause interference). Maybe it is possible, but I see it as unlikely.

Best way to protect your screen from being read? Put your entire computer in a Faraday box/cage including your screen (although impractical, it blocks out all signals). Only way to prevent streaker reading your mind? Make one for your head

-Stephen

[Archangel-Amael]

[QUOTE=phoenix910;53258]

And in terms of reading your screen from across the street - entirely possible with CRT monitors, but in terms of reading LCD monitors via cable emissions, I doubt that, because the shield cables (often with coaxial shielding) so that they don't pick up outside signals (which cause interference). Maybe it is possible, but I see it as unlikely.


Markus Kuhn a proponent TEMPEST shielding has conducted tests that have shown even LCD screens to leak some information but the majority comes from the DVI cables that are used both inside and outside of the screen as being the best source to find what is refered to as compromising emanations (CE).

[Barry]

I'm also fully in agreeance with shamanvirtuel. I have also recovered data fully formatted multiple times, it's not like it's an impossible task. And the DoD standards of 3 or 7 times overwrite aren't for secure data erasure, that's just for everyday files - they delete their average things like that. So if that's not secure erasure, then they can obviously get that back. What's another three times gonna hurt?

And in terms of reading your screen from across the street - entirely possible with CRT monitors, but in terms of reading LCD monitors via cable emissions, I doubt that, because the shield cables (often with coaxial shielding) so that they don't pick up outside signals (which cause interference). Maybe it is possible, but I see it as unlikely.

Best way to protect your screen from being read? Put your entire computer in a Faraday box/cage including your screen (although impractical, it blocks out all signals). Only way to prevent streaker reading your mind? Make one for your head

-Stephen

There's a whole thread on how to shield your computer over at the netstumbler forums. The 3 to 7 rewrite thing with the dod is for inter-office transfer of equipment. If they're actually getting rid of the equipment, the drives are physically destroyed.

[balding_parrot]

I would say this is possible. Probably the way it works, and I have no citations in reference to this, just general knowledge of how the stuff works, is that when the machine is shut down, the RAM probably still has it's last data stored in it. That data is probably only deleted over time (whatever the RC time constant is on the RAM) or when the machine boots up normally and the BIOS wipes the RAM for a clean boot.

If the RAM were pulled out within the RC Time Constant timeframe, then it could effectively be read through a specially designed device. I would think that if they were to wait at least 3 hours, chances are, they wouldn't be able to recover anything off of a stick of RAM.

I do believe the RAM experiment is true. It seems quite possible that RAM still holds its memory even though it doesn't have an active voltage applied. Not knowing the type of RAM involved its hard to say how it works, but perhaps the RAM doesn't automatically clear it's registers when voltage is applied. My guess is most RAM is like this in that you have to issue a command to it to zero it out. Then again zero it out might not actually zero out the data just a register that says it's got data? It seems plausible that this could be done with the Cache on the hard drive also. After all it is just memory.

Thank you both for that.

The explanation given at the time of how it worked, was that each of the circuits when power is removed will still have a slight bias towards it's last condition, be that on or off. That condition will remain for a period of time, although the degree of bias towards that state will diminish over time, With the ability of reading it successfully equally diminishing. A circuit that is designed to store data in this way is inherently going to hold such a bias for a far longer period of time.

As a side note, you only have to look at a decay curve for a simple RC circuit to know that the charge in that circuit will to all intents and purposes never return back to zero. I know this is a very simplistic view of part of the circuit that actually is in RAM, but it does show the principal at the heart of it.

As for recovering data from a HDD, there are a lot of big companies that do that sort of thing every day, so does that mean that they are just conning people into believing that it can be done. And if what you are saying is true, how come they are still in business, and how come the DoD etc go to such extreme measures to ensure complete deletion of data.
You have yet to show any documentary evidence that such data recovery from a HDD is impossible, yet there is a plethora of evidence that proves it is indeed possible.

In case you missed the post

So you speak of documented irrefutable proof that it is *not* possible?

I certainly hope so, before you spout off calling people liars.........

But then, maybe you have somewhere else you'd rather be anyway??

Where is this proof that you obviously must have to be calling people liars like you have ??

[Duritoxn]

There's a whole thread on how to shield your computer over at the netstumbler forums. The 3 to 7 rewrite thing with the dod is for inter-office transfer of equipment. If they're actually getting rid of the equipment, the drives are physically destroyed.

Ah, the voice of reason.

Your data is more recoverable than you think. Sort of scary then, that some companies and individuals sell old computers with hard drives intact on ebay.

[Barry]

Ah, the voice of reason.

Your data is more recoverable than you think. Sort of scary then, that some companies and individuals sell old computers with hard drives intact on ebay.

I know a guy who bought a whole shitton of cf cards off ebay to see what he could recover. AFAIK it was all just boring vacation type pics, no "private pics".

[balding_parrot]

I know a guy who bought a whole shitton of cf cards off ebay to see what he could recover. AFAIK it was all just boring vacation type pics, no "private pics".

I heard you lost a bunch of money on them, and still have quite a few that you haven't managed to sell yet.