Hiding Secret Messages In Skype Silences 79
Orome1 writes "A group of researchers from the Institute of Telecommunications of the Warsaw University of Technology have devised a way to send and receive messages hidden in the data packets used to represent silences during a Skype call. After learning that Skype transmits voice data in 130-byte packets and the silences in 70-byte packets, the researchers came upon the idea of using the latter to conceal the sending and receiving of additional messages."
There goes that idea (Score:5, Insightful)
If you are going to hide something, don't let everyone know where you put it.
Now that the exploit has been discussed it will be watched out for.
Re:Eloquent silence (Score:2, Insightful)
UDP overhead is 28 bytes for ipv4. Add in overhead for the audio codec to represent a timeframe for a sound and 70 bytes become reasonable.
Re:Eloquent silence (Score:5, Insightful)
Exactly what I was thinking.
You would think that a packet specifying X seconds of simulated silence could be packed into a few bits, so maybe two bytes should suffice.
Were you planning on sending that "two seconds of silence" packet at the _start_ of the pause? If so I know a few theoretical physicists and at least one state lottery commission who would _love_ to see your algorithm.
Re:Eloquent silence (Score:2, Insightful)
Btw, Silence is a sound for computers which is represented by a flat line or basically the value of 0. Not getting packets and getting a value of 0 are different things whereas the former can be due to packet lost and broken connection while the latter is an actual value.
Re:Go old school rather than packet level? (Score:0, Insightful)
If it were "undetectable", it wouldn't be able to be spotted by the *receiver* either.
It may well be *innocuous*, but 'undetectable communications' are about as useful as 'unbreakable encryption', and every bit as oximoronic.