Slashdot Mirror
Digital Camera Image Verification
Polo writes "While reading dpreview, I noticed that among several new products, Canon has announced a Digital Image Verification Kit to prove that an image taken by a particular camera has not been modified. It's disturbing to think about the conditions that would allow digital images to be accepted in a courtroom. I guess one defense would be to figure out how to 'verify' a photo of shark attack..."
The card reader connects to a computer USB port (only Windows 2000/XP compatible at the moment).
Suddenly, this throws out the validity of anyone who owned a Mac or was using FreeBSD as their primary desktop operating system.
The World is Yours.
The kit consists of a dedicated SM (secure mobile) card reader/writer and verification software. When the appropriate function (Personal Function 31) on the EOS-1D Mark II or EOS-1Ds is activated, a code based on the image contents is generated and appended to the image. When the image is viewed, the data verification software determines the code for the image and compares it with the attached code. If the image contents have been manipulated in any way, the codes will not match and the image cannot be verified as the original.
So it's basically an MD5 (or equiv hashing method) of the image at the time it's taken? Too bad -- I thought they had a unique idea to verify images that had already been taken.
Two or three questions I suppose:
All in all I suppose it's a neat idea -- hope it actually works before somebody is on trial for his life though...
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
1.) Take picture :-)
2.) Photoshop picture
3.) Print picture
4.) Take picture of printed picture
It won't work. From everything I've seen, attempts to verify ANYTHING digital will be cracked within a week or three.
1. take picture
2. modify picture
3. regenarate image verification data
4. profit?
Canon is very cool - they are one of the only camera manufacturers that still supports the cheapest, non-proprietary form of flash media in all of their cameras - CompactFlash.
To everyone out there: you are an idiot if you buy a camera that does not support CompactFlash. You'll end up paying twice as much for the media.
In other good Canon news, they've announced that they'll be releasing 20 new digicams this year. Hail to the king, baby!
Life is the leading cause of death in America.
I'm willing to be that one of the first customers for this software is the tabloid newspapers/magazines. They pay small fortunes of photos of celebrities in their most intimate and private moments and without a way to verify digital photographs they could be duped of millions of dollars.
There's nothing concerning about digital images in the courtroom.
Ask the photographer, under oath, "is this representative of what you saw?".
If it was, he says so.
It's really the same as with any other evidence that can be tampered with. If someone testifies under oath that it is what it is then there's no difference between a digital image and any (many?) other types of evidence.
Slashdot? Oh, I just read it for the articles.
any image, not just a digital one, can be changed, modified, or completely faked. Yes, digital technology makes it easier, but this is not a new phenomenon. Juries know (and should be told) that any image introduced into evidence might not be real and could have easily been altered by the other side. Depending on who took the image and the chain of possession, weighed against how believable the picture actually is, will determine how much weight the jury gives to a given photograph.
These digital picture verifiers are nice but not the end of the question. A validation from one of these machines is just some more evidence that the picture is real. It's not conclusive and shouldn't be taken as so. In fact, the evidence of validation from one of these machines might not even be allowed into court if they're extremely unreliable. Daubert to the rescue.
Stupid people make stupid things profitable.
When the appropriate function (Personal Function 31) on the EOS-1D Mark II or EOS-1Ds is activated, a code based on the image contents is generated and appended to the image. When the image is viewed, the data verification software determines the code for the image and compares it with the attached code. If the image contents have been manipulated in any way, the codes will not match and the image cannot be verified as the original.
Note to self: run the signing software *after* altering the image. If the image was alrady signed, display it, take screenshot, alter the image, and re-run the signing software.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
By doing an autocorrelation of the image, you can detect parts that have been copied, but the mathematical part is not that easy, particularly if there are uniform noiseless areas (sky).
I can still deal with 1D autocorrelation, but in 2D my maths skills are rusty...
Non-Linux Penguins ?
You don't have to re-invent the wheel.
This is a funny article on why you shouldn't use your digital camera when trying to detect / prove the existance of ghosts. No not like a bad flat screen playing Quake, but like Casper the Friendly.
He seems real serious about it too....
This is mostly for the use of Law Enforcement, where the cops have to prove the photos taken as evidence, haven't been tampered with....
"We're also trying to annoy our customers like Adobe, but that software is still in beta. We might try to license some software form Microsoft, as they seem to be the leaders in that field."
Wayne continues, "Our R&D department has some great ideas, such as forcing the user to take every picture twice, erasing photos at random, and my personal favorite - increasing the time between pressing the shutter release and when the picture is taken!"
"We won't stop until our product is unusable at last!"
This is just general, but there are many rules about entering photograghs and other documents.
Fight Spammers!
What if you had a different piece of hardware other than the camera that can write to the memory card? I wonder...can you buy those off the shelf today?
I know! I was the one on the ladder. One of the scariest moments of my life, as well. Hanging from a chopper is bad enough, but having sharks take dives at you is worse.
The separate images that the debunkers claim they're made up from are the fakes.
How it works
The kit consists of a dedicated SM (secure mobile) card reader/writer and verification software. When the appropriate function (Personal Function 31) on the EOS-1D Mark II or EOS-1Ds is activated, a code based on the image contents is generated and appended to the image. When the image is viewed, the data verification software determines the code for the image and compares it with the attached code. If the image contents have been manipulated in any way, the codes will not match and the image cannot be verified as the original.
So the upshot is that they use a memory card which has some additional security functionality. This additional functionality can only be accessed by the card reader and the camera.
The the crackers simply need to break that functionality or bypass it. This could be accomplished by breaking the camera's firmware (or the card reader) and changing it, or sitting between the USB reader and the computer (software or hardware wise) and changing the data as it goes along. Alternately it woud not be impossible to modify the camera so it gets the image from a computer instead of an image sensor.
The ultimate, however, would be to break the protocol and keys between the reader and card or camera and card. Hopefully they are using a good encryption algorithm with fully secured sessions and a long key. I'd hate to see this broken in less than a few months time.
-Adam
I'm thinking this is for Canon to target the camera at a specific market where legal evidenciary issues come into play: crime scenes, insurance, autopsy, etc. This is likely not to be a feature that will appear for most consumer products.
What it really shows is more about how the professional film camera market is facing realistic competition from digital cameras.
I would love to see the firmware write all photographs to the CompactFlash already encrypted to my public key. Of course, that would mean you'd have to (1) forego viewing the images on the LCD, or (2) require the private key and allow entering some kind of text phrase or biometrical key.
It's not like I engage in some sort of espionage or porn market, but I want to see more publically available data devices support cradle-to-grave security.
[
All this hinges on the testers having an _original_ copy of the image in addition to the supposedly modified version.
/dev/null
Let's say someone tries to use a doctored digital photo as evidence. They eliminate the original md5 with the aforementioned screenshot trick, and then recreate it. The photo is contested on the grounds it is a fake. To prove it, they go off and get their wonderous DVK-E2 kit, and then they get their md5. The test works just fine, so they know the md5 has been altered, so they go and ask for the original image. And so where is the original image? Do they have it? No, of course not, because it went on a little stroll down memory lane and landed without a sound in the fastness of
Have we accomplished anything here?
Defenestrate Windows...
You mean that was not a picture of the Olsen twins giving some guy a blow-job?
I would point out that there was a noted case where someone took pictures with a reduced scale ruler to make a crack or pothole look that much bigger. The picture was all original but already manipulated.... Ultimately I think I would go with affidavits (this is a true, accurate and unmodified picture of what it purports to be) containing a print in b&w on the affidavit as well as an md5 checksum of the pic file or files if I was attaching a cdrom or floppy. There are issues here about submitting info this way which I wont go into, but this may be appropriate in certain situations. And btway- I really like my canon a300. CF, AA batteries, 3.2meg.. no zoom function though, and a little large.
I dont do meaning of life questions.
This is correct. The federal rules of evidence (and the rules of most states) require that the witness testify that the photograph actually depicts what it is that the witness says it depicts. The witness could paint the photograph, if he were an adequate artist.
All writings and papers and so forth have to be introduced in such a way as to either not be hearsay or to gain a hearsay exception.
I don't know why you might think that a video movie is more sacrosanct than something like a blood sample. Both require someone to testify about them and in both cases the person can convict someone simply by lying.
By the way---remember the video in the Microsoft trial? They could have easily faked that too.
Sooner or later you have to rely upon people to tell the
truth and there is no way around that fact. These cameras will make no difference whatsoever.
The camera stores information about focus distance, focal length (zoom) and exposure parameters as well as other data in each image (in EXIF format, commonly). Example:
Also, you'd also have to account for the distortion effects that are measurable and reproducible with each camera model. For example, barrel or pincushion distortions compound if you take a shot of an existing picture.
The problem is, that kind of noise will only appear in areas with low exposure (due to the gain control which amplifies the noise). When the sensor is getting sufficient light, the noise becomes less pronounced to invisible.
ElGamal was a legacy key and not really meant to be used that much. The one slashdot poster who said he was affected (when that came out) said he chose it because he liked the sound of the name. ElGamal is legacy and shouldn't really be counted against GPG
Photos.