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A Linux-Based "Breath Test" For Porn On PCs
Gwaihir the Windlord writes "A university in Western Australia has started beta testing a tool that's described as 'a random breath test' to scan computers for illicit images. According to this article it's a clean bootable Linux environment. Since it doesn't write to the hard drive, the evidence is acceptable in court, at least in Australia. They're also working on versions to search for financial documents in fraud squad cases, or to search for terrorist keywords. Other than skimming off the dumb ones, does anyone really expect this to make a difference?" The article offers no details on what means the software uses to identify suspicious files.
It looks for files like "guyongirlonsheep37.jpg"
Test your net with Netalyzr
Quick! Whats the RGB color value for "pink" ?
Don't blame me, I voted for Kodos
Helix can do most of the "breath test" functionality referred to, and is a great forensic Linux distro. Helix is also considered a viable method in which to capture data that is consistent with the chain of custody that is required for evidence to be presented to a Judge. Check it out... http://www.e-fense.com/helix/Download.html
Computer forensics is hard, expensive, and time-consuming. I would guess this is just a tool for cops to save cash in criminal investigations compared to hiring an expert, or at least to triage which systems need to be investigated by an expert.
Also, if your friends are IT staff and your online watercooler is slashdot.org, you may think everyone but the "dumb ones" knows how to encrypt a drive. But the reality is that the vast majority of criminals have never heard of Truecrypt.
A slashdotter who didn't build his own computer is like a Jedi who didn't build his own lightsaber.
Now everybody in Australia is guilty until proven innocent!
I thought that was the founding principle of Australia :)
The article offers no details on what means the software uses to identify suspicious files.
I highly suspect that the police don't want people to know the details of how sophisticated their technology is because they don't want to embarrass themselves. Keeping an aura of mystery and FUD around themselves and their techniques is also a form of psych-ops; it's the chrome facade of a lemon.
Might want to avoid the US and the UK as well.
For kiddie porn you want to scan for small swaths.
<cheesysoundtrack>
*WEEW*
"License and registration please...are you drunk ma'm?"
"No Ociffer, I swear to Drunk I'm not god"
"Step out of the car please. I'm giving you a breathalyzer test. I need you to blow on this"
"Wait...wut...come on I just want to go home"
"Well if you don't want to do the breathalyzer I can give you a balance and mental aptitude test..."
"Come on just cut me a break, I live just down the road, outside of these dark woods on this lonely country road"
"Well OK, but if you want me to skip the breathalyzer, I need you to blow on _this_"
</horribleacting>
</cheesysoundtrack>
"When information is power, privacy is freedom" - Jah-Wren Ryel
'Human skin tones' is a pretty wide range though. Even just restricting it to 'white' people gives you a big range of colours if you consider the various shades of tan / sunburn - anything from deep red to pale white through dull brown. If you want to find naked black- or yellow-skinned people then it's an even bigger range. If something is blue or green you could probably guess it's not naked skin (unless the person is bruised, or wearing body paint), but without factoring in shape as well it's pretty difficult to tell if something is human coloured or not.
Actually, human skin is pretty much all the same hue, it just has different saturation levels. If you convert each image to HSV from RGB, you can just look at the hue component and people all pretty much look the same. This is common in computer vision techniques for identifying skin.
-Taylor
Worldwide Military budgets: $2100 billion. Worldwide Space Exploration budgets: $38 billion. Really, world? Really?
Once upon a time, a company did this, and sold their product to another corporation so that they could monitor employees' email. If I recall correctly, it ended in tears when somebody got sent baby pictures.
The minute you change the contents of that hard drive, you open the door to claims of tampering with evidence. "Your honor, the kiddy porn only showed up after the police 'inspected' it. They planted all of it." That's what 'chain of custody' means. Police have procedures to follow to ensure that evidence can't be tampered with.
Good meatspace analogies would be OJ Simpson's DNA showing up on evidence only after he gave a blood sample. More hypothetically, say the cops take your backpack as evidence. What happens to it? Well, it sits in a police warehouse storage facility somewhere, possibly for months. If any cop has access to that backpack on demand for this whole time, then there is effectively have no way to prevent someone from stuffing the bag full of drugs. No accountability. So for meatspace evidence, there are very strict rules that say you have to keep track of every person who has access to that piece of evidence. There can be no exceptions.
The equivalent in the computer forensics world is that you have to guarantee you didn't alter the original equipment's hard disk. Proper forensic analysis involves making a *copy* bit-for-bit and then analyzing this copy. The new thing here is a bootable CD that presumably has been rigorously tested and certified (by who, I couldn't say) that it literally cannot modify the hard disk.
Remember, we were selected by the best judges in England...
The difference between the USA and Australia - first, England rounded up all of it's religious fanatics, and sent them to the American colonies, then they rounded up all of these criminals, and send those to the Australian colonies....
What the parent poster is trying to illustrate is that when a particular type of humor that roughly fits the phenotype of a reductio ad absurdum, or farce, in modern parlance, and, further, is based upon the implication of knowledge, which creates the perception of an 'inside joke', magnifying said statement's entertainment potential, has the piece of knowledge, previously conveyed via implicit communication, explained explicitly the statement so doing actually assumes the full weight of the previously mentioned 'absurdum', leaving only a fact and a non sequitur.
:)
In other words, it's not funny when you explain it, but thanks!
(Notes to subsequent posters: a formulaic representation where the function of the humorous statement is subsequently undermined by the explanation and proved untrue (or similar), while funny, would have taken a bit more time than today's actual work-a-day requirements would allow. I would however be pleased to enjoy another's attempts to compile such an argument.)
Disclaimer: This message is intended as humor and not flamebait, contrary to the anonymity assumed during the posting of said message. Furthermore, contrary to what is stated above, this post is the opinion and property of Slashdot. (Just kidding on that last part.)
-HH
on a flight from DFW to LAX, I was recently asked by the American in the seat next to me 'where New Zealand got it's heritage - because, you know, Australia was a criminal colony'.... my answer: oh, dont mess with New Zealand...
Australia rounded up its worst criminals and sent them there...
So the Australians won the coin toss and got to pick?
None of them can see the clouds; The polished wings don't care.
Well technically, I think we've all been IN one at least once in our lives, females included. However I suspect that's not the point you were going for.
Official Heretic from the "Church of Global Warming". Proven right thanks to whistle blowers. AGW = Flat Earth Theory
The difference between the USA and Australia - first, England rounded up all of it's religious fanatics, and sent them to the American colonies, then they rounded up all of these criminals, and send those to the Australian colonies....
In those grand traditions I propose the following test...
Turn the laptop on, tie a large weight to it. If it floats, it's a witch! Burn it! If it sinks it's innocent. Pity it didn't survive.
These posts express my own personal views, not those of my employer
Your post contains invalid markup: you can't interleave tags like that.
"[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz
I was a C-Section baby, you insensitive clod!
One of the environments I worked in had a sniffer that grabbed all the images (and associated session information) it could see on the wire for that organization (or at least a subset - there was a LOT of traffic involved). It would then process those images and generate a "skin folder" of suspect imagery. We could then sift through that skin folder looking for illicit browsing, etc.
Yeah - it caught porn. But it also contained a lot of imagery of furniture, mars landscapes, deserts (it really liked the time pictures of camel spiders in Sandland were the hot topic of emails) and other such not-skin-oriented imagery.
Actually, no. This method does not work - which is what I said at the time. Because this misinformation is apparently still around, I decided to run a test.
I took a large file (1600x1200 px) and then applied a basic red-eye reducing algorithm to various spots on the image. The result: visually, exactly the same image.
Then I turned to my trusty Apple Preview. I resized each photo to 9% of its original size (144x108 pixels), and the proceeded to turn the color saturation down to 0 (black and white). I then saved each file in a compressionless TIFF format. Lastly, I computed the md5 hash for each file.
Result?
MD5 (smlimg3.tiff) = d300d23ce0ca2d6dcc7188665b1e2ada
MD5 (smlimg4.tiff) = a1cf7d59f9bf4ccceb6651c5f08750dd
Let me say this once more, in case anyone else who blindly accepts anything they read on the internet has heard this: THIS TECHNIQUE DOES NOT WORK. To compare two SIMILAR images, one needs to use an image comparison algorithm - of which there are many. Hashing ONLY works on two images which are EXACTLY the same.
If you doubt the test or the results, I would be glad to email you all of my test pictures so you can see them and calculate their md5s for yourself.
3 words. British prison colony
The big question is -- can this program tell the difference between a porn photo and a photo of Fidel Castro eating a banana?
You just solved the CAPTCHA problem.
It seemed like the sort of thing that would work in theory, but I can see why it doesn't. Even changing a few pixels in the corner (I made a 10x10 white square) gave drastically different MD5s.
I'm a moron for blindly accepting a +5 post as fact, please mod down my original post.
Obligatory Soundbite Catchphrase
...oh, and your mom.
(Sorry, had to)
3 words. British Penal Colony There, fixed that for you
Don't anthropomorphize computers. They *hate* that.
Now you will get a ton of Ubuntu backgrounds....
The whole point of a hashing algorithm like MD5 is that even a single bit change should change lots of random bits in the resulting hash. If it was predictable it wouldn't be suitable for it's purpose.
Jason