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Hiding Packets in VoIP Chat
holy_calamity writes "Two Polish researchers say they have developed a system to hide secret steganographic messages in the packets of a VOIP connection. It exploits the fact that VoIP uses UDP, not TCP; it is designed to tolerate some packets going missing -- so hijacking a few to transmit a hidden message is not a problem." You may also be interested in reading the original paper.
Didn't /. just post an article a few months ago about how the NSA figured out a way to block steganographic messages in VOIP?
Tic-Tac-Toe, Global Thermonuclear War, and relationships all have the same winning move.
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Thanks Slashdot, because I really want to go to Slashdot to get links to a story that I have to pay to read.
The complete article, accessible without NewScientist subscription, may be found here.
____
~ |rip/\/\aster /\/\onkey
It's not a sectret anymore now is it?
Stop this research. No way I am going to say GoodBye to my Secretary. She knows a lot more than just stenography;)
hilarious
Based on the RFCs for VOIP they are supposed to support UDP and TCP per the new specs. Most companies are moving to support both so you can choose, but some of the large companies are going to TCP because this is what all of the 'Unified Communications' packages go with (such as Microsoft Office/Live/Communicator, etc).
One of the reasons they are leaning this way is security. Go figure.
Besides that, I don't really see the point. What does this solve that just encrypting sensitive data wouldn't?
If you want to hide packets over VoIP I suggest making "beeping" noises.
Here is the actual paper as a clean PDF. This is the good version.
The linked Technology Marketing Corporation page mentioned in the parent post has only the beginning of the article. It also has 24/7 Media ads in the middle of the article, Google ads on the right, TMC ads at the top, bottom, and in boxes within the article, buttons for more promoted services at the left, a Flash banner at the top, ads from OAS at the lower right, a Digg button, and an email signup box. Oh, and the page refreshes itself every two minutes to change the ads.
Article by Wojciech Mazurczyk and Krzysztof Szczypiorski... wow ... Did they encrypt and hide their original names ?
You shall see a cow on the roof of a cotton house.
This has been looked at elsewhere:
http://voipcc.gtisc.gatech.edu/
as more and more companies move their voice system over to VOIP, this creates an interesting dilemma: how do you prevent information leaks from secure sites when your telephone system can act as the carrier? Which probably means that we'll have more company snooping around and more "by using this system you agree that your privacy will be raped daily" forms we all have to sign when we get hired.
-- All this knowledge is giving me a raging brainer.
I didn't even know we knew what a Stegosaurus sounded like, and these guys hid its messages in VoIP traffic!
stuff |
...if you're using steganography in your VoIP data stream to imbed pr0n images, then you've invented a clever new form of digital phone sex, right?
While VoIP certainly can use UDP, it's also quite possible (and even common) for VoIP calls to use TCP as the transport. Hell, the original paper even mentions steganography over TCP.
Saying "VOIP uses UDP, not TCP" is overly simplistic. RTP can run over either UDP or TCP, while SRTP runs over TLS-over-TCP.
I support the Center for Consumer Freedom
"Hey." ... ...
"Hey."
"I'm sending you a stenographically encrypted file through this call."
"Oh, okay."
"Uh, hello?"
"Sorry, I gotta give it enough talk time to transmit."
"Oh, gotcha."
"So, how's the family?"
So. You're the one paying for my internet surfing.
Sounds like you need adblock.
Deleted
Doesn't skype use it's entire userbase to broadcast packets from the sender to the reciever? Wouldn't this allow people to communicate practically anonymously?
VoIP doesn't "use UDP instead of TCP". VoIP (which is usually SIP+RTP, but there are other protocols out there used to carry voice over IP networks) can use UDP over TCP, and that configuration is the most common one. But not the only one possible as the article suggests.
Also, the article in the /. article kind of suggests that VoIP (which is a concept, not a protocol) can use only UDP, which is not true. It's like saying Internet is used only for HTTP.
Isn't VOIP illegal in most of the countries where data hiding needed to protect yourself from the political police?
Telephone service is usually a government monopoly in the developing world. VOIP bypasses the government telecommunications monopoly. And since that monopoly is so profitable, the government authorities in these places violently suppress anyone that they catch using VOIP.
What kind of information would be hidden in VOIP transmissions? General political tracts and religious books are too large for the limited space available. Specific information about meetings, such as, "Go to this address at this time and ask for Raul if you want to receive absolution from an ordained priest" in places where Christianity is illegal? Or criminal activity information, like "go to this address at this time and ask for Abdul. He'll have the bomb that you need to blow up the infidel day-care center"? Or, in the USA, drug deal information like "We received your PayPal transaction, Thank you very much. Eight grams of dynamite skunk weed for you is located in a crushed Mountain Dew can in the gutter exactly sixteen feet south east of the bus stop sign at the corner of First and Main. We will pick it up if you don't do so by 3:30pm Tuesday"? I've always wondered why simple dope dealers don't use Internet technology for anonymous untraceable transactions? Could it be because most dope dealers are stupid, or just old-fashioned?
Why would someone want to hide information in a VOIP transmission when they could use an encrypted e-mail for the same purpose? This isn't a rhetorical question. I'd like to know your opinion. I don't have VOIP, so you'll have to take a chance and post it here.
It does get one thinking, though... So many things on the internet appear to be governed purely by entropy; how many of them could conceivably be used for steganographic purposes?
/. accounts set up for bots to automatically comment on stories, with an algorithm somewhere to scrape and concatenate certain characters based on a key consisting of times and offsets...
Imagine a series of
Come to think of it, there's no reason why this necessarily couldn't be the case with some of the vast volumes of blog comment spam out there. Spread out wide enough and with a resilient enough algorithm, there could be more than enough signal to cover for the noise of spam-killed comments...
Your mind is clear / The things that you fear / Will fade with how much you / Believe what you hear
I think the future will see the use of trojan/virus techniques to send data. It's already been fairly well proven that stopping botnets is next to impossible given current technologies, attitudes and ideas on the part of administrators and engineers, and most importantly that AI bears not a candle compared to Natural Stupidity.
Forget just VoIP. In the future we'll hide communications networks under multiple layers of encryption inside trojan'd everything that is awfully hard to tell innocent user data from something else. We'll probably also host websites and files that way in a coalescence and then expansion of BT/P2P and anonymous remailer methods but not so much with identifiable clients but instead viral ware that people choose to allow on their machines so as to prevent privacy invasion by government and business.
If my grammar and spelling are off, I am [distracted/tired/careless] (take your pick)
It must be cuz it sure as shit don't work right. I could reach more people sticking my head out the window and yelling than with AT&T.
There are sometimes other places to hide data:
I can't remember whether it was FTP Software of NetManage, but one of those used to hide the serial number of the software in the bits between the end of broadcast ARP requests and the end of the Ethernet frame.
That way they could check for duplicate license keys on the same net without bothering anybody. Only worked across the broadcast domain, but that was adequate for that purpose.
There's lots of other places too.
RTP packets have optional extension headers that can be used, DNS can hold extra information in parts of the query and response packets - I once encountered someone tunneling music feed via buggered DNS packets. (It became very visible when it caused a Cisco firewall to go haywire.)
Voice is one place for stego, but Video over IP can use a lot more bandwidth, and gives you more places to hide info--you can do more with the codecs, and can "hide" information in the picture itself (hey, the bad guys could use sign language.) :)
One interesting thing about the paper is that it implies that some types of DRM mimic stego. Is this a reason to outlaw DRM?
Say this:
;P )
W Szczebrzeszynie chrzszcz brzmi w trzcinie.
(note: your head may explode)
(PS. and don't look at my nickname
One that hath name thou can not otter
Just read the paper. While their research is entirely sound (no pun intended), the value of their research is pretty limited.
.wav encapsulated G.711 or G.722.1 file. That would lose the RTP packets altogether while leaving the audio playable. But doing so would probably delete the hidden message.
In circumstances like Skype (not RTP), it is possible to talk and text chat at the same time. All of it is encrypted.
The application of this type of stegonographic message is for stored data. But for that, the data would have to be stored. There's just not point in storing a voice conversation as RTP packets on the users' system. In fact, it would be almost ridiculous to store audio in a network session specific payloaded form.
Typically, it would be better to just store the audio as a
So far as I can tell, there's no application for using this in the real time context and if you're trying to hide your data, storing it in RTP encapsulated audio packets on disk is pretty silly since it isn't a standard file format.
If you want to hide something, find a way to hide it in a jpeg. png, etc...
- Sincerely yours, the DHS.
/. comment system cut out one letter with diacritic...so, I'll just use closest thing from the roman alphabet:
;)
chrzaszcz
There, should be much easier to you
One that hath name thou can not otter