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xtofury
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security related question
#10572182 - 06/25/09 04:46 PM (14 years, 10 months ago) |
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Ummm I keep wanting to post pics here but I'm a little paranoid I'm thinking I should buy a camera that I use specifically for taking them with (like one of them 100-150 dollar digital ones), I mean I know what sorta sneaky shit they put in this stuff.
From what I understand all printers and cameras generate a unique watermark which is embedded into the pictures, scans and printing it does. And that this watermark may be preserved through stacks of these processes (such as a printed digital photograph, that is rescanned and printed on a different printer -- which means a watermark for the camera, a watermark for the 1st printer, a water mark for the scan maybe the same watermark for the 2nd print, so a total of 3 unique and 4 total watermarks embedded into the document).
Just wondering but isn't it kind of stupid posting pictures without regard to what else the camera is being used for (when they could be keeping the pics on this site and reading the watermarks off them, then attempting to detect the watermarks in other pictures on the net using a spider -- thereby possibly cross-referencing with facebook by any chance?)
I really don't think I'm being too paranoid on this one, seems like it would be a terrible mistake to be doing something an then have evidence kicking around of past activity which they can pin to a person, and come busting in.... it's only a matter of time before they do that. So I decided a camera specific to the task is a fucking smart idea.
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george castanza
Lord Of The Idiots!

Registered: 10/21/02
Posts: 8,762
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Re: security related question (moved) [Re: xtofury]
#10572201 - 06/25/09 04:49 PM (14 years, 10 months ago) |
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This thread was moved from Mushroom Cultivation.
Reason: More/better answers in the proper forum.
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Alan Rockefeller
Mycologist


Registered: 03/10/07
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The shroomery filters out EXIF data.
That may be different from watermarks though.
I know some color printers print watermarks in little yellow dots.
I have never heard of a camera having a watermark embedded into the image, but its certainly possible. A google search shows lots of digital camera watermarking related hits, but all of them are for copyright reasons and its generally something the photographer has to enable.
No one has ever gotten in trouble posting images to the shroomery, watermark or not.
Resizing an image and saving it using a photo editor will wipe out some data.
If you are paranoid buy a cheap camera off of CL and just use that.
Probably not worth the effort to combat a possibly non-existent problem however.
I recommend that concentrate your security efforts more on real world issues - traffic stops, narcs, friends who talk too much, apartment inspections, roommates who smoke tons of weed, loud parties, posting identifying personal information, etc.
I have seen more than one ID request where people used their drivers license as a background for the mushrooms.
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Psilon
Curious cultivator



Registered: 06/18/09
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I think what you're referring to by 'watermarks' is digital camera sensor pattern noise. The CCD (sensor chip) in a digital camera is imperfect, and will usually have a consistent pattern of digital noise that emerges based on the properties of a given photograph (things like specific colors or lines). If an investigative department with A LOT of money and time and experience to waste managed to get ahold of a large amount of pictures taken with the same camera that produced an identifiable noise pattern or the camera itself, they MIGHT be able to analyze the noise and link a given camera with a picture (the analysis is imperfect and not completely reliable). Not a lot of people have the resources or knowhow to do this, and it's probably not something you'd need to worry about unless you're under a really serious investigation by some serious organizations.
As mentioned above, if you're super paranoid get a cheap one somewhere but it's really not worth the effort and there are other things you really should be worrying about.
-------------------- Nothing I say is real
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PsychoReactive
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Registered: 05/22/09
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Loc: Cocalero
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Re: security related question (moved) [Re: Psilon]
#10572787 - 06/25/09 06:40 PM (14 years, 10 months ago) |
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Just resize all the photos and save as JPEG in paint to remove when the photo was taken and what camera was used.
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PNutButta
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You could also use a steganography program in an off-label fashion, such as taking a file of random junk and embedding it into the image. This would have the effect of mucking with the lowest significant bits of the image, where uniquely-identifiable noise is generally located. You wouldn't need a stego program to perform this, but it would be a natural artifact of using one. Since many forms of stego are detectable, this may have the added benefit of producing a red herring for the investigator. They may end up wasting time and resources attempting to recover the random, useless data that you embedded into the image.
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xtofury
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Re: security related question (moved) [Re: PNutButta]
#10575513 - 06/26/09 07:32 AM (14 years, 10 months ago) |
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I'm just wondering, aside from the random noise within the image produced by imperfections in the silicon and lensing system of the camera, wouldn't it have been a smart move on part of national security to implement a watermarking system that would make such photography more traceable? I mean seriously think about it: it could conceivably be designed to allow for super-imposition of multiple watermarks (like in, why tis assumption that an image can only handle a single watermark at a time?) depending on how the system is employed. The gov has had their hands all into printers and stuff, how daft would one have to be to surmise that since they had this system in place for printers before the age of digital photography that the feds might have pre-emptively put something in place?
I learned one thing in life and that is to never underestimate the system (or a foe). Whatever technology they have is decades ahead of consumer level stuff don't kid yourself.
From what I understand is that a watermark can be embedded in many places within an image using an algorithm and even if part of the watermark is destroyed is can still be read. Is it really that far of a leap to think that maybe these so called experts out there could have come up with that very sae idea after having had a system in place for printers and realizing over it's time that there were a few flaws to the system that they had used there?
I mean how dumb is the sytem, really? (I know it can be dumb as a rock sometimes but that doesn't necessarily mean all of the time)
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Alan Rockefeller
Mycologist


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Re: security related question (moved) [Re: xtofury]
#10576377 - 06/26/09 11:54 AM (14 years, 10 months ago) |
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Quote:
wouldn't it have been a smart move on part of national security to implement a watermarking system that would make such photography more traceable?
Most cameras aren't made in the US.
Also there are many manufacturers, it would be hard to convince the really cheap brands to add something like that.
Quote:
I learned one thing in life and that is to never underestimate the system (or a foe). Whatever technology they have is decades ahead of consumer level stuff don't kid yourself.
Its also good not to overthink things. There are many more likely ways to get busted, like a traffic stop or a packet sniffer.
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xtofury
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ummm cameras -- yes, mos sensors, no. There are lots of manufacturers of digital cameras but not lots of companies that are designing their own and fabricating their own silicon for digital imaging, Kodak being one of them.
Actually it's only good for cops for people like us not to overthink things because that's what gets you caught. Driving around with narcotics is a pretty stupid idea and thus I don't really think I would do that.
Ever hear of mems? The single molecule detection systems that have already been made (not on a large scale). Right now actually there has been one made to detect rdx, the active compound found in plastic explosives. Driving around and going through airports and shipping stuff are eventually, and quite quickly (dependent on making mems devices cheaper to build) going to become stupid ideas.
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