[1]the physics arXiv blog [2]Breakthrough calculations on the capacity of a steganographic channel Posted: 03 Nov 2008 11:49 PM CST [3]Steganography Steganography is the art of hiding a message in such a way that only the sender and receiver realise it is there. (By contrast, cryptography disguises the content of a message but makes no attempt to hide it.) The central problem for steganographers is how much data can be hidden without being detected. But the complexity of the problem means it has been largely ignored in favor of more easily solved conundrums. Jeremiah Harmsen from Google Inc in Mountain View and William Pearlman at Rensselaer Polytechnic Institute in Troy NY, say: "while false alarms and missed signals have rightfully dominated the steganalysis literature, very little is known about the amount of information that can be sent past these algorithms." So the pair have taken an important step to change that. Their approach is to think along the same lines as Claude Shannon in his famous determination of the capacity of a noisy channel. In Shannon's theory, a transmission is considered successful if the decoder properly determines which message the encoder has sent. In the stego-channel, a transmission is successful if the decoder properly determines the sent message without anybody else detecting its presence. Previous attempts have all placed limits on the steganographers channel for example, by stipulating that the hidden data, or stego-channel, has the same distribution as the cover channel. But Harmsen and Pearlman have take a more general approach which takes some important steps towards working out the channel capacity over a much wider range of conditions. The results are interesting and in some cases counter-intuitive (for example, adding noise to channel can increase its steganographic capacity and in some cases, mounting two attacks on a channel instead of one can do the same). It's fair to say that Harmsen and Pearlman are pioneering of the study of steganographic capacity and that with this breakthrough, the field looks rich with low hanging fruit. Expect more! Ref: [4]arxiv.org/abs/0810.4171: Capacity of Steganographic Channels [5][arXivblog?i=RJeacp] [6][arXivblog?i=KtAON] [7][arXivblog?i=4bYNN] [8][arXivblog?i=vTEyn] [9][arXivblog?i=dwzIN] [10][arXivblog?i=ty7nn] [11][arXivblog?i=FpGdN] [12][arXivblog?i=oaKyn] [13][arXivblog?i=Ao24N] You are subscribed to email updates from [14]the physics arXiv blog To stop receiving these emails, you may [15]unsubscribe now. Email Delivery powered by FeedBurner Inbox too full? [16](feed) [17]Subscribe to the feed version of the physics arXiv blog in a feed reader. If you prefer to unsubscribe via postal mail, write to: the physics arXiv blog, c/o FeedBurner, 20 W Kinzie, 9th Floor, Chicago IL USA 60610 References 1. http://arxivblog.com/ 2. http://feeds.feedburner.com/~r/arXivblog/~3/441756399/ 3. http://arxivblog.com/wp-content/uploads/2008/11/steganoraphy.jpg 4. http://arxiv.org/abs/0810.4171 5. http://feeds.feedburner.com/~a/arXivblog?a=RJeacp 6. http://feeds.feedburner.com/~f/arXivblog?a=KtAON 7. http://feeds.feedburner.com/~f/arXivblog?a=4bYNN 8. http://feeds.feedburner.com/~f/arXivblog?a=vTEyn 9. http://feeds.feedburner.com/~f/arXivblog?a=dwzIN 10. http://feeds.feedburner.com/~f/arXivblog?a=ty7nn 11. http://feeds.feedburner.com/~f/arXivblog?a=FpGdN 12. http://feeds.feedburner.com/~f/arXivblog?a=oaKyn 13. http://feeds.feedburner.com/~f/arXivblog?a=Ao24N 14. http://arxivblog.com/ 15. http://www.feedburner.com/fb/a/emailunsub?id=8632699&key=kesJ612ZsV 16. http://feeds.feedburner.com/arXivblog 17. http://feeds.feedburner.com/arXivblog ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE