Hiding Information in Retransmissions
Wojciech Mazurczyk, Milosz Smolarczyk, Krzysztof Szczypiorski
The paper presents a new steganographic method called RSTEG (Retransmission Steganography), which is intended for a broad class of protocols that utilises retransmission mechanisms. The main innovation of RSTEG is to not acknowledge a successfully received packet in order to intentionally invoke retransmission. The retransmitted packet carries a steganogram instead of user data in the payload field. RSTEG is presented in the broad context of network steganography, and the utilisation of RSTEG for TCP (Transport Control Protocol) retransmission mechanisms is described in detail. Simulation results are also presented with the main aim to measure and compare the steganographic bandwidth of the proposed method for different TCP retransmission mechanisms as well as to determine the influence of RSTEG on the network retransmissions level.
I don’t think these sorts of things have any large-scale applications, but they are clever.
Posted on May 28, 2009 at 6:40 AM •
This is cool. It writes like a normal pen, but if you run a hair dryer over the written words they disappear. And if you put the paper in the freezer the words reappear. Fantastic.
EDITED TO ADD (5/20): This is the same technology as the widely available Pilot Frixion pen. Here’s a temperature sensitivity test, and a freezer test.
Posted on May 19, 2009 at 6:49 AM •
Here’s a tip: when walking around in public with secret government documents, put them in an envelope.
A huge MI5 and police counterterrorist operation against al-Qaeda suspects had to be brought forward at short notice last night after Scotland Yard’s counter-terrorism chief accidentally revealed a briefing document.
The operation was nearly blown when Assistant Commissioner Bob Quick walked up Downing Street holding a document marked “secret” with highly sensitive operational details visible to photographers.
The document, carried under his arm, revealed how many terrorist suspects were to be arrested, in which cities across the North West. It revealed that armed members of the Greater Manchester Police would force entry into a number of homes. The operation’s secret code headed the list of action that was to take place.
Now the debate begins about whether he was just stupid, or very very stupid:
Opposition MPs criticised Mr Quick, with the Liberal Democrats describing him as “accident prone” and the Conservatives condemning his “very alarming” lapse of judgement.
But former Labour Mayor of London Ken Livingstone said it would be wrong for such an experienced officer to resign “for holding a piece of paper the wrong way”.
It wasn’t just a piece of paper. It was a secret piece of paper. (Here’s the best blow-up of the picture. And surely these people have procedures for transporting classified material. That’s what the mistake was: not following proper procedure.
Posted on April 10, 2009 at 7:06 AM •
I’m sure you need some skill to actually use this, and I’m also sure it’ll get through airport security checkpoints just fine.
Posted on March 6, 2009 at 6:05 AM •
They’re used to smuggle drugs into the U.S.
Since the vessels have a low profile—the hulls only rise about a foot above the waterline—they are hard to see from a distance and produce a small radar signature. U.S. counterdrug officials estimate that SPSS are responsible for 32% of all cocaine movement in the transit zone.
But let’s not forget the terrorism angle:
“What worries me [about the SPSS] is if you can move that much cocaine, what else can you put in that semi-submersible. Can you put a weapon of mass destruction in it?” Navy Adm. Jim Stavridis, Commander, U.S. Southern Command
Posted on February 10, 2009 at 12:59 PM •
There’s a bill in Congress—unlikely to go anywhere—to force digital cameras to go “click.” The idea is that this will make surreptitious photography harder:
The bill’s text says that Congress has found that “children and adolescents have been exploited by photographs taken in dressing rooms and public places with the use of a camera phone.”
This is so silly it defies comment.
EDITED TO ADD (2/13): Apparently this is already law in Japan.
Posted on February 3, 2009 at 6:08 AM •
This is a 2 Gig USB drive disguised as a piece of frayed cable. You’ll still want to encrypt it, of course, but it is likely to be missed if your bags are searched at customs, the police raid your house, or you lose it.
Posted on December 10, 2008 at 7:02 AM •
Sidebar photo of Bruce Schneier by Joe MacInnis.