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Study Finds Low Use Of Steganography On Internet
schnippy writes: "New Scientist reports on new study from the University of Michigan that argues that steganography (the science of obfuscating communications) is not in wide use, or at least not on the 2 million images they scanned on eBay. Earlier this year, USA Today reported that Bin Laden was using steganography to disguise his communications. Full study is available here. Wonder how long before someone sets up a distributed computing client to help search for Bin Laden's secret communications? :p" Niels Provos' research was mentioned in Slashback not long ago, and this article is based on the same research.
Half of slashdot posts are encrypted evil plots for mass destruction.
Je t'aime Stéphanie
The whole point of stenography is that people CAN'T spot the fact that you're using it!
i think the extinction of the dinosaurs wiped out steganography; the mysteries of how the stegasaurus learned to write with its' tail will never be known to any of us...
...does anyone else think that "steganography" is just the latest in annoying media-driven hysterics? Every month there's a new buzzword that exists simply to point out the "evils" of the internet...
MAYBE this is just another one of those words!! With so many other more effective and simple methods of encryption (read: PGP), why would anyone go to all the trouble?
So does someone have a super-duper steganography-detection algorithm, or what?
Maybe they assume in color-discretized images that images having RGBs one-off of their surrounding pixels are steganographic? I gotta write a filter to induce 1-off color changes then, just to keep 'em busy. =)
Or are these people just freakin morons?
--- The reclining dragon deeply fears the blue pool's clarity.
Steganography is supposed to hide messages as well as possible. That's the whole point. So wouldn't a study just find the use of bad steganography, that is, stego that is easy to detect?
And who says that you have to post images to send a message? Maybe posting a baseball card for sale means that a cell is to attack on the day that the auction closes. A Sammy Sosa card means we fly into the Sears Tower; a Thurman Munson card means the WTC. The starting bid is the price is the time at which it's to happen.
The whole point of steganography is that the outside world doesn't even know what your encoding system is, much less be able to decipher it.
From what I heard, not that I have any clue what I'm talking about other then what I've seen on the news and water cooler talk. But, they don't even use computers for the most part. Not only are they low-tech, they are no-tech. I don't see what the fear is other then some goverment officials taking advantage of the mass hysteria.
Steganography in and of itself is fairly powerful. However, the real beauty lies when you combine it with encryption. Encrypt your strings of bytes, strip off headers and define the headers through some other mechanism and THEN you'll have truly clandestine communications. The best steganography is the kind no one even knows is there (as has been mentioned previously).
I know a group of guys who were literally taking all of the porn off of the alt.binaries newsgroups to look for hidden messages, but gave up do to the volune, the low chance of actually getting a hit, etc. In other words, it will be impossible to tell if the image you have is actually encoded.
An interesting look at what steganography is for beginners.
- There is no significant use of steganography on the Internet.
- Nobody uses steganographic systems that we can find.
- All users of steganographic systems carefully choose passwords that are not susceptible to dictionary attacks. (emphasis mine)
In response to number 3, I'd like to say, "well, duh". Anyone clever enough to transmit messages via steganography is not going to be stupid enough to potentially compromise themselves by choosing a simple password.But beyond that, this search is limited to one small part (Ebay) of the entire Internet. There are certainly many other places where images can be transmitted inconspicuously (certain usenet groups come to mind).
To me, this seems like a "feel good" story designed to put people at ease. It has little actual merit.
www.scorbett.ca
Yeah, if I was going to hide a message, I'd use commonly available tools already out there. *sigh*
Terrorists are not stupid. I would think a home-brew methods would be better in many circumstances.
These people aren't communicating with 45 meg Powerpoint Presentations outlining the plans. Short, concise messages could be encrypted with previously agreed upon one-time pads, hidden in a few bytes of an image, or even across 8 or 10 images across multiple sites. These people have time and a mountain of data to hide in.
Ebay seems like a poor choice for stenography. First off, you have to actually sell something to get a picture on Ebay (IIRC), and I doubt the terrorists are going to want to bother with having buyers on their back all the time.
It seems to me like it would be much easier just to set up some random Geocities site with text like:
Hi, I'm Lisa Smith and this is my site about me and my 10 cats!
Then include several pictures of 10 different cats, including some with covert information. If you need new information you can reencode some of the pictures and reupload them. Other messages can be sent by subtly changing the HTML (adding and deleting extra spaces for instance).
I still can't figure out why they thought the images would be one Ebay.
I read the internet for the articles.
Apart from the fact that by default, good steganography should be undetectable, it appears that e-bay is a poor site to use. By default, the user posting a sale has to exist in some manner, unless a new identity is created for each item to be sold - which makes sense, but the bottom line is that it is a pain to keep creating e-bay accounts, and making up e-mail addresses.
Something on the newsgroups would be a much better place to look. the alt.binaries.pictures.* areas. Almost total anonymity.
If I were to want to communicate this way, I would avoid e-bay.
gus
.. if only.
This is important, because the FBI, NSA, CIA, etc. should definitely NOT be wasting its time looking into these crazy claims of hidden messages.
The cake is a pie
Someone pointed out these paragraphs to me, from the BBC's coverage of this story:
"No, really, we havehave to look at more pr0n now..."
GROGGS: alive and well and living in
I know people are joking about it being the whole point that you can't find it in use, but reading the article, this is not far from the truth. The researchers admitted that the method they used only hunted for known, commercially available techniques, and that there were other techniques available that would not have been spotted. Add in any totally novel methods people may have used themselves.
Still, if we're going to give these researchers funding...
I couldn't help laughing at the title. The first thing that popped into my head was, "How do you measure the amount of steganography on the internet?" Seems like the answer is that there should be a lot of nearly useless information, a low signal-to-noise ratio if you will. Which, I'm sorry to say, is a very accurate description of the internet. :P
:)
Okay, okay, now I'll go read the article.
Happy winnowing and chaffing!
Dave
It seems a bit sketchy to conclude that if something doesn't happen on e-bay, then it must not be happening anywhere else on the internet.
I could easily encode a message into an image, and NOBODY could detect that one was there, even through careful examination... why would this study be accurate?
For example:
-take an original image as a reference
-encode a message into binary 1's and 0's (use encryption if you like, or just the binary ascii equivalent)
-go through the image in a certain direction, and change each pixel value by 1 to encode a binary "1", or leave it alone to encode a binary "0".
-distribute a "reference image" separately that can be used to decode the image (like a key)
-use a simple algorythm to compare the original and reference, which will give you a binary sequence
-decode the binary sequence using whatever method you used to encode it
Unless you have the reference image, you're screwed. Changing RGB values by 0 or 1 will not be detectable, and will easily blend in with the noise of most images.
The only thing you can't do is compress the image with JPEG or other "lossy" compression routines.
How could you detect this? How could you prevent it from being used? You can't, unless you know the reference image. I could post secret messages on the front page of CNN.com and nobody would know (ok, assuming I had access to CNN.com to post an image).
MadCow.
I used to have a sig, but I set it free and it never came back.
is like trying to prevent a germ warfare attack.
The truth is, that even if we had known about the WTC attack we could not have prevented it without causing an economic loss of millions of dollars in the city of New York that our current hero-mayor -- Rudy Giuliani -- would have prevented, to the accolades of his fellow citizens if an attack had not come.
You have to do so much alteration to the medium which you are trying to keep free of bad stuff, be it Internet porn or our daily lives, that the medium itself is changed beyond recognition. It's not worth it.
Unlike a specific cryptographic algorithm, steganography is a group of methods that take advantage of the huge volume of information that passes over the internet.
Unless you want to dramatically slow down the transfer of all information, making sure the file looks the same at each gateway it passes through, there is very little you can do to catch people who disguise information in this way.
ObL is a modern terrorist, using modern methods to operate and communicate. He want us to be afraid of our own modern trappings and conveniences in our lives; if we try to make it impossible for him to communicate, we give up far too much ourselves.
We must allow full encryption freedom, full steganography freedom, and all otehr lifestyle freedoms in the US and around the world.
Traditional deterrence methods, such as massive military response, should be used to stop terrorists; we need to stop them after their attacks, and instill fear in others who would attack through a terrifying military response, unfortunately against the innocent as well as the guilty.
Goat sex free since 2001
Earlier this year, USA Today reported that Bin Laden was using stegnography to disguise his communications.
In other new, Osama bin Laden has unilaterally agreed to stop sending encrypted messages, in advance of forthcoming legislation U.S. legislation restricting cryptography. When approached for a quote, bin Laden quipped, "I no longer wish to be secretive in my communications, from here on, I vow to only Exchange pictures of beautiful American women with my friends in the United States.
Seen any BadMarketing lately?
Tampering can still leave traces, and once you know how a tool works, you may be able to detect it. This turns out to be the case with almost all of the currently available steganographic tools. From the Slashback link:
"[The researcher has] been developing several interesting tools to do steganalysis during the course of his universal stego engine development: (http://www.outguess.org/) including stegbreak (which can detect images produced by all popular stego tools -- except outguess)....
Of course, this only works if you know the tool, so this research only would detect the use of "off-the-shelf" steganography, as the researchers point out. From the article:
The technique may not be infallible. The methods used by Provos and Honeyman were particularly aimed at uncovering use of steganographic tools already released on the internet.
There are more advanced methods of hiding communications within images that involve using active, as well as redundant parts, of the underlying code. Sushil Jajodia of the Centre for Secure Information Systems at George Mason University in Virginia, US, says that this could have evaded detection but would require considerable technical sophistication.
BTW, it's "steganography". "Stenography" is what those speedy typists in courtrooms do.
After an extensive search I have concluded that Flying Saucers, Santa Claus and the Tooth Fairy don't exist because I couldn't find them.
I am Slashdot. Are you Slashdot as well?
Ignoring terrorists for the moment, what about the rest of us?
Most of us agree that use of encryption is probably a good thing. (Envelope as opposed to postcard and all that.)
So, how do we get normal folks to use encryption? By creating tools that interface well with the tools normal folks use. If that means writing a plugin to outlook, so that the braindead can encrypt the latest virus they're trying to pass me, we should do it.
The study is about detecting stego when normal tools are used for the encryption. It doesn't suggest that the message is easily extracted, and it's foolish to suppose that terrorists will only use the most commonly available tools.
What can we do to get normal folks to use stego, PGP, or other forms of encryption?
I think that we spend a lot of time on Slashdot arguing about Linux and it's place on the desktop, when we could be focusing on encryption as well, and how to make it ubiquitous.
The report omits a glaring error in the study. Namely, that the researchers never checked out the alt.binaries.pictures.steganography group. And the moral? Never send a scientist to do a lurkers job.
"Old man yells at systemd"
When everyone is scouring the internet for hidden messages, a better form of steganography would avoid using the internet at all.
Granted, I suspect it's just the media that's obsessed by the internet, so any intelligence organization worth its salt would be doing a thorough monitoring of all possible communications channels.
It's like the article says: Using a code word in a telephone conversation or a radio broadcast would provide a far easier way to communicate in secret.
Accountability on the heads of the powerful.
Power in the hands of the accountable.
there has been speculation that Osama Bin Laden has hidden messages in pornographic images posted and swapped on Usenet
.jpg, .mpg, .avi, .bmp, .pcx, .mov and .html file ever posted. Also I have every .txt, .doc file from alt.stories.erotica.camel.
If they posted in alt.binaries.erotica.veils or alt.binaries.erotica.bondage.camels between 1990 and 2001 I have every
This
EBay is a nice choice for this: it is a symbol of the DotCom hysteria, and there are already a lot of stories about it (people selling their child's names, organs, nazi ensigns).
Now you idea is much more logical, but emotionnaly unnaceptable. Having the FBI raid eBay is one thing (nobody works there anyway) but suspecting people who show pictures of their cats, that would be truly evil (everybody knows somebody who likes cats).
This is not about logic, but about finding somebody to blame. It's much easier to suspect and to blame people you don't know... Why do you think comes the idea that Bin Laden had to use the internet?
Why even make the site 'public'? Restrict access, and don't have a link on your main page pointing to a hyper-secret-photo.
It's absurdly trivial to hide something, for a short time at least.
"Ignorance more frequently begets confidence than does knowledge"
- Charles Darwin
WHAT?
Stenography is nothing of the sort!
Stenography is shorthand. It's a method of quickly writing information down in an abbreviated form that's still fully comprehensible later.
Part of the problem with not recognizing stenography anymore is the fact that it's no longer really taught in schools. With the advent of compact tape recorders and dictaphones, the need for steno skills pretty much evaporated.
Chas - The one, the only.
THANK GOD!!!
Nice page. Another good one belongs to Professor Dave Touretzky (he of the anti-DMCA campaigns): it's a gallery of ways to hide DeCSS steganographically, which explains the concepts pretty well.
GROGGS: alive and well and living in
Or, more realistically...
Your tax dollars were given to researchers to surf pr0n.
"Faith is the last resort of a desperate man" - Me
Didn't you know? Only law-abiding U.S. companies can make security software!! This is why implementing encryption backdoors is such a good idea for national security as well as the national economy, because the world needs to use our products to ensure high quality security.
"He's more machine now than man, twisted and evil."
with the "backdoor" that Ashcroft feels is so important? Now that the US Government has so blatantly advertised its intent to try to get encryption standards with a "key" that can be known to a government agency, why would anyone "upgrade" to such a system? It's not like the ones we use now don't work.
Had the US Government been doing the things that it, itself, recommended back in 1991 to better secure airports, the terrorists would have had no chance to hijack the aircraft in the first place. Corporate (airlines) interests fought those to a standstill, however. Now they blather about a backdoor in encryption systems as if that would fix the problems they, themselves, ignored
No one ever had to evacuate a city because the solar panels broke!
Well, now it is my patriotic duty to spend time checking out UT servers for potential terrorists!
"Rub her feet." -- L.L.
/.
If you want to securely signal someone, you start with the previously mentioned "here's a picture of my cat" in a web ghetto.
Encrypt some textual child porn into the picture. Once the thought police find that, they stop looking at the data and come looking for you.
This ensures that dopy morals enforcement cops will trigger your early warning system before the theoretically subtle and dangerous secret agent heros show up.
But, since you are smarter than a gelded water buffalo, the porn contains key words that indicate meaning based on knowledge shared by the correspondents. For example, any reference to Marsha Brady combind with the word "pigtails" would mean that you've shot a bunch of morals cops and relocated your base of operations. You get the idea.
Criminal and spy communications have been done through the personals in newspapers for a century at least. Restrictions on encryption impose no significant hardship on persons who consider themselves either above or beneath the law.
--Charlie
Stenography could be used to hide an illegally encrypted message in a picture that is being sent to someone via email, etc. There is no reason to use E-Bay as a means of communication like this.
Better yet, take your message and encrypt it using public key encryption without the use of a key escrow. Then file the encrypted message as an XOR key for one-time use, and use it to encrypt a copy of this message...
LedgerSMB: Open source Accounting/ERP
The specific rumor, back in Feb2K, when this whole hysteria started, cited EBay. That's why.
I love the smell of Karma in the morning
There was supposedly a whole system of signals guiding African-American slaves to escape to the north. The signals were hidden in quilts, which could be left out in the open. It's written up in Hidden in Plain View, and you can see some of the symbols here. This was very low-tech, and the end-users didn't even have to be literate. Haven't you seen spy movies where signals were passed according to whether a curtain was open or shut, the color of a shirt hanging on a clothesline, etc.? This kind of low-tech signal would leave much less footprint than anything composed or transmitted via machine.
Ok, so we have a study that says that only a small percentage of pictures on eBay seem to have some kind of steganographic content, but none of them can be confirmed to actually contain this information. You can conclude several things from this, depending on your personal bias:
-Steganography is not used on the web.
-Steganography is not used on eBay.
-We can't detect steganography.
-Any steganographic we can detect can't be decoded.
-Steganography isn't widely used - yet.
You can mix and match these to fit your personal agenda, which I'm sure many people will do. In reality though, these results say almost nothing. The only way to know where, how, and how often steganography is used is to find out from the people using it.
Unfortunately, I have a feeling some people in Congress and elsewhere in the US government will use this as proof that if they can control encryption, there won't be too much use of other methods of hiding data. Ignoring all of the flaws in this conclusion, there is a further flaw in the assumption that by changing the security in encryption, the amount of use of other methods will remain the same. I would not be surprised if there aren't any people on eBay using steganography, nor would I be surprised if the same was true on most other sites; with available alternatives, this is just one of many tools that could be used to transmit messages securely. If the alternatives are removed, more effort will be spent on steganography, resulting in more widespread use and more resistance to detection. In other words, a ban on secure encryption would just encourage development in other areas, even if such development is dormant right now.
On a final note, if you want to look for steganography, try a sleazy porn site. Not that I've seen any myself, but I've heard that they toss all kinds of random stuff up on those, grabbing the images from all over the internet. This would seem to make a more representative sample than a site full of people selling their junk.
It's almost unbelieveable. Specially for the big church ones.
I would have just emailed a plaintext message "Achmed, meet me at WTC at 9". The whole f**king FBI/CIA could have read that message Sept 10 and not thought anything about it.
Slow down, cowboy! It has been 4 hours since you last posted. You must wait another few hours.
Snow White,
The owl howls at midnight.
Rumpelstiltskin
Always keep a sapphire in your mind
Searching for a method that is not susceptible to computerised scanning such as the research mentioned in the article, I have decided the best way is to always send my secret messages on the insides of drinks cartons, in December. I have had gret success in passing on information with out detection this way, so I heartily recommend you all adopt eggnoggraphy as your chosen espionage technique from now on.
A pizza of radius z and thickness a has a volume of pi z z a
Two simple points :
1) you do not ever want to use the same image for multiple messages. The fact that the same image is shown but has subtle differences is a strong indicator of the presence of stegoed data.
2) you do not ever want to restrict access to the images containing stegoed messages - that enables traffic and association analysis.
If you do place stego data in an image make sure that the image is an original ( eg from your own digital camera or scanner ) and that once you have produced the modified image you destroy all copies of the original - see #1 above.
The point isn't "there is no steganography on the web." The point is "here is a system to look for steganography."
In typical mass media fashion, both New Scientist and Slashdot go for the flashy story rather than the more interesting point of the research.
Folks,
Passing secret data, if you have resources, is not that hard. Look up any book on "Field Craft" in the field of "Intelligence"
Real low bandwith messages are trivial - aka, attack tommorow. It could be a chalk mark on the wall, a newspaper folded a certain way etc.
Even more fun is to pass LOTS of encrypted messages in the clear, but 99% are nothing but random noise. Look up the topic "Numbers Station"
Add in a few cutoffs / dead drops, and it's trivial
Let's say OBL wants to send a message. He could use a combination of low/high tech. He uses a courier to move the data from where he is, to the first drop. The next person has NO idea where OBL is. They use another drop. That person sends a message via the net "Look at the new picture of my dog" might be the whole message - the data isn't even in the picture. Youc could go even further. Use some sort of Steg, but spread the message across multiple images.
The whole trick is to make the signal/noise ratio low enough that you can't see the signal unless you know where to look
-- 73 de KG2V For the Children - RKBA! "You are what you do when it counts" - the Masso
why transliterate. Just use unicode.
That would work if we knew they were using unicode, but we don't. They could just as easily be using a transliteration into Roman letters.
I like to play children's songs in minor keys.
"We're all sons of bitches now." --J. Robert Oppenheimer
Everything I read about stegonagraphy seems to rely on hiding sensitive information within a single, seemingly innocous file.
I've always thought it'd make more sense to spread it between files so that, with the encoding based on differences between the files.
For example, say I want to transmit the binary number 1011, for whatever reason. 1011 is in decimal number the 11, so now I take an image, make a single pixel change at (1,11) and then make some humorous 'before and after' changes to the image, like moustaches, body parts or captions. Whatever, just don't alter row 1.
Send the two pictures, the receiver checks the difference between row 1 of the two images, and gets 11, which he can then converts to 1011. From there, he uses whatever binary-message decoding.
You can thus encode a 512-bit message by making a single pixel change to a 264x512 image.
Include those two images in a pic gallery of 200 images, and now it really becomes hell for anybody trying to detect it.
And that's using a very, very simple method.
Vs lbh pna ernq guvf, ybt bss abj. Tb bhgfvqr. Syl n xvgr.
I'd bet money that messes w/ messages...And their detection...
LFS. Have you built your system today?
Why even make the site 'public'? Restrict access, and don't have a link on your main page pointing to a hyper-secret-photo.
Because that would defeat the whole point of using steganography. The idea is that terrorists can talk to each other without the government knowing that they're even talking to each other. If only one person visits the site, you might as well just email the encrypted data.
If 10,000 people all view the picture, how do you know which one is actually receiving the information? It's just one more layer of "security".
ok then your [sic] infringing on my copyright! Could you as [sic] me next time before STEALING my comments for your own?
Why use EBay when you can get CNN to distribute your stegonagraphically encoded messages for you?
ok then your [sic] infringing on my copyright! Could you as [sic] me next time before STEALING my comments for your own?
exactly vot ve vant them to think. Ve make beeg trouble for moose and squirrel for sure now.
Another proud carrier of the $rtbl flag
The canonical answer is - for the same reason you put a letter in an envelope, not just write on a postcard every time. for a lot of things (particularly love letters and business negotiations) you don't want anyone but the intended recipient to read it.
Q: Why would a Terrorist use software that has a US/UK/UN backdoor, surely they'd write it themselves (hard) or download it from the net (easy)?
They wouldn't use broken software, and it is impossible to force them to without a 100% scan of all email.
Q: Assuming most T's are small organisations surely they'd use replacement words, which unless you've infiltrated the group, you'll never understand.
Or use steganography, yes.
Q: The UK government have been talking about bringing in ID cards in the face of the WTC horrors. Doesn't the US have ID cards already? Every time I wanted a drink in Las Vegas I got 'carded' and I'm 30, so it's not like they don't get checked.
It is sad, but all sorts of control freaks have come out of the woodwork, waving laws that got voted down last time they tried it with "terrorist" scribbled in at a few places to make them look a bit different. ID cards would do nothing against terrorism - it is likely we will never know the real names of the terrorists, given how many seem to have popped up and said "no, I am still alive here" when named.
-=DaveHowe=-
Yes but it seems reasonable to infer that if you can't find anyone doing it badly, it's fairly rarely used. It's human nature that for every guru there are 10-100 novices.
$5 / month hosted VPS on linux = awesome!
Overall steganography applications might arise, this harms especially United States' international status considering other matters in neareast geopolitical future or relations you ought understand, really unwanted now!
PS. If you're a terrorist, read the first letters of my above paragraph.
If you're talking about applying the reverse of various well documented steganography algorithm on an image (or an mp3-song, for that matter) and then looking at the result, you're wrong.
All you will get is a random stream of bits. And without the private key to which this message was encrypted, you have no possibility to know whether these random bits really are some supersecret data, or just random noise introduced by the digital camera, the image processing software or the compression algorithm.
Why would you put the images on ebay? There are plenty of forums that aren't as public, and don't require as much information to register, and best of all, don't cost money.
There is absolutely no relationship between there being no stenographic images on Ebay, and the use of stenography by Bin Laden or other terrorist groups.
Seriously, think about where you would put your images? I would say porno boards would be the best place, possibly newsgroups. Tons of people look at porn, so the traffic wouldn't seem strange, and theres so much out there, you wouldn't even know where to look if you were looking for said stenographic images.
As for distributed clients... I'd love to see a distributed client that started searching all the pr0n sites out there, checking them for secret messages. Could you see that popping up as your screen saver?
Its just not going to happen.
Captain_Frisk
I'd use an obscure MP3 sharing site, not jpegs. Something that does not arouse suspicion if you try to do it covertly.
Nothing as suspicious as trying to hide something seemingly innocent, but if they take it too far (pr0n jpegs or warez for instance) it would attract attention again.
The pattern of where the bits are hidden has to be a constant because the reciever has to be able to find them to :)
The pattern does not have to be constant; it simply has to be derivable by the recipient. For example, we could agree that when I diddle the low-order bit of the blue component of a pixel, the red component of the same pixel gives the offset to the next pixel which contains data...etc.
We can get as complex as we like, provided we agree on the system. This is one of the things that makes it silly to even talk about "measuring steganography on the internet." It's also one of the case where "security through obscurity" pays off--or, to quote an old adage, people don't rob banks they can't find.
To take this even further, imagine a system like Blonde=0, Dark hair=1; Large breasts=0, Small breasts=1; Full frontal=0, Partial=1; etc. where the pictures are to be read in the normal reading order. This provides a 64 bit convolution key, which is used to combine all of the images from another site; the result is used to select letters from the postings on an unrelated newsgroup...
I defy anyone to prove that this sort of system is or isn't being used. And note that it need not use any standard encryption software.
-- MarkusQ
In any case, except for the nefarious use by criminals, or a few people having fun, there's no reason to use steganography very much. The hope is not to be detected when you do use it.
True, most stego falls into security through obscurity, and few systems have fit the design specs for a good stegosystem:
- Difficult to detect that a message (hereinafter a "Watermark") exists in a signal without a key (possibly public key for sdmi; secret key for terrorist applications)
- Difficult to remove the Watermark without unacceptably affecting the signal or using a second key (secret key for sdmi; not that important for terrorist apps)
SDMI's four stegosystems failed because it was too easy to remove the watermark from the signal.Will I retire or break 10K?
As a science steganography is vary old. One of the first book on the subject steganographica was written by Gaspari Schotti in 1665. It has however been a subject of limited public interest until vary recently. This is not to say that various steganographic techniques haven't been used ovar the years. On the contrary, many intelligence agencies have uses steganographic techniques to smuggle secrets our of various countries throughout the cold war and before. One of the best known ancient uses of Steganography was in the book Hypnerotomachia Poliphili published in 1499. The point is, it's been around for a vary long time, there just hasn't been any public interest.
--CTH
--Got Lists? | Top 95 Star Wars Line
I think the detection of steganography in an image file, given reasonable smarts on the part of the stego software designers, is totally impossible. A typical plain text email message might have 1k words, to be generous. This works out to about 40k bits (5 characters per word, 8 bits per character). A 2048x1536 tiff file, common with today's digital cameras, is about 10+ MB in size. I think that hiding the 40k bits in 10MB of binary image file would result in a file that would pass any practical test, statistical or otherwise.
Also consider this technique, you (the encryptor) could run the statistical tests on the output file and tweak garbage bits at random until it would not raise any alarms. The design principle would be: 1. Encrypt your message, 2. Insert a compensating set of (probably ordered) bits into the image. 3. Test for randomness, you want to have the final encrypted/hidden output look like the original by every statistical measure you can test for. Repeat steps 2 & 3 until done.
The basic principle is that you keep the number of encrypted bits in the hidden part buried in the file low relative to the size of the file the message is buried in; I am not a crypto guy but maybe someone who is would care to comment. I would not bet on the TLAs in this race, it's too easy to hide stuff.
if I was conducting a Jihad, I wouldn't trust the internet either.
Jihad is not terrorism. In fact, the Qur'an prohibits terrorism against innocent civilians. Islam is a religion of peace, and jihad does not refer to a "holy war" but merely "struggle ... such as an internal struggle to follow Islam, a struggle against oppression, or a struggle for peace" (source:).
Will I retire or break 10K?
Why would they even be posted on e-bay where lots of personal information has to be given out. The sites with less public traffic is usualy sought out when hiding information to reduce the number of chance discoveries. All two parties need is a mutual place to check in. Some personal obscure "My vacation pictures of Alabama" on My-Yahoo may be a better place to look.
The truth shall set you free!
If I really wanted noone ever to guess what I am sending to someone, I would use a number, a LARGE number of free internet services to send SMALL portions of my message through them. I need many accounts on geocities, yahoo, tripod, ebay, maybe some news groups, and I would distribute my super secret message among them in a fassion that would only be known to me and the person I am communicating with. Every message would be sent in a different manner with different accounts. Decrypt this.
You can't handle the truth.
Sooo, let me ge this straight.
... Man.
The report states that the Internet, the most obvious and well known center of lies and obfuscated information, a place so ravaged by dis-information that we as a people may have lost all hope of ever pulling ourselves out of ignorance and delusion, a place where major information providers lie (such as regarding Bin Laden using encrypted JPGs... he never did), and this report...
This report... thing... says Stenography isn't in wide use. WHO CARES!
According to my friend, steganographic messages posted to newsgroups were up the week before 9/11/2001.
If someone is trying to hide information on the internet why would they use web pages. If I were going to hide information on the web I would do it with a secure webserver not eBay.
Second of all I would use more obscure protocols and programs than http. I would use things like irc or a propeitary online bbs.
And third I would use things that would be easier to hide information in than pictures. Movies are ideal because you have a large amount of space to hide your data and it would introduce less entropy (or whatever).
Terrorist and bad people aren't going to go out of their way to comunicate right under our noses, just like they'd never use encryption with backdoors.
"...steganography (the science of obfuscating communications..."
Shouldn't that be, "steganography, the science of encrypting communications as image files"?
Seeing as how "the science of obfuscating communications" is otherwise known as "cryptography". This would seem to be confusing the part with the whole.
-Kasreyn
Kasreyn: Cheerfully playing the part of Devil's Advocate to hairtrigger
Users install the plugin as an altruistic act, much as they choose to run the SETI@Home screensaver. In fact, this thing could just be a screensaver that runs against all images in the browser cache during idle time. You would get moderate coverage of the web, but would likely miss tiny, unpopular pages. Unfortunately, these are likely to be the kind of contrived pages that would be used to post steno'd images.
Or call the cool gang at Google or Inktomi and have them crawl and test a large fraction of the web as a service to their country. Their customers would probably be cool with stale searches for a couple weeks if they explained why. The gov't could build a big cluster to do this themselves for very little money (couple $100k).
This is actually a project that could help locate real live terrorist steno, if any exists and has not already been pulled down. If they went to the trouble of using steno, the data is certainly encrypted. But, I'm sure some interesting traffic analysis would be possible.
What are the moral implications of such a project? If image file steno is always detectable given enough effort, do its users really have any expectation of secrecy? How long before the anon-remailer crowd starts generating tons of steno background noise all over the web, so everyone can hide more easily?
(*) Their test function looks pretty basic. Since this is a distributed idea, it could probably do a more detailed analysis. Someone correct me, but even very sophisticated image file steno is detectable if you do the correct analysis, right?
PS: Ebay is a horrible choice. I believe you need to provide a credit card # to become a seller. Ebay wants a fairly strong notion of seller identity, so they can identify and remove people who lie/cheat.
...you've discovered the true purpose of Fat Chicks In Party Hats!
Well, it's been shown you can figure out a lot of what a CPU is doing by watching power consumption (very accurately).
And by watching time-sharing you can get a fairly good idea about what other users on the computer are doing. Someone showed this being used to figure out a secret key, based on how much CPU time they got while the target was decrypting something. I imagine you'd need quite a few decryptions before you got it all, but even a hint helps the cracking.
Yes, these subtle communications channels can be very powerful.