When Dexter goes to conference

Tonight is the night, welcome party. Be careful, it is hard to find a way among this jungle. Everybody welcomes you with big smiles. Some are sincere, others lie. Some are your friends, some appreciate your work, others are reviewers who nailed down your paper with unfair arguments. But one is never sure. Who is who?

"- Hey! Hello! Are you presenting a paper?"

Strange to ask me such a pretendedly innocuous question right away! Usually one starts with "when did you arrive here?"… This is suspicious. I always attend conference to present a paper luckily accepted. But this conference is the only exception, and therefore his question is very embarrassing. He knows this, he did it in purpose.

Except that I noticed your little game, I am security minded, I see worst case attacks everywhere, I am Dexter. The server cuts cheese with a big knife. And the lake is just nearby. It is time to say goodbye to my 'good friend'. There will be a no-show at this conference.

Invited speakers

How to boost the appeal of a conference which had a relatively low number of submissions?

Here is the trick:

1) Maintain the acceptance ratio as low as possible,

2) Fill the program with sexy invited speaker talks.

Examples:

- Ton Kalker @ MMSP 2010, "Protected Video Distribution in the Networked Age"

- Gabor Tardos @ IH 2010, "Capacity of collusion secure fingerprinting - a tradeoff between rate and efficiency"

- Pim Tuyls @ IH 2010, "Hardware Intrinsic Security"

- Boris Skoric @ IH 2010, "Security with Noisy Data"

Miss cucumber, from the travel agency desk.

SPIE get closer to the Village People

For 2010, the SPIE conference on Media Watermaking, Security and Forensics leaves San-Jose to meet San-Francisco (more exactly its International Airport).

On good trafic conditions, the Airport is 30mm far for downtown by car, and the same by the subway, which means possibly interesting after-sessions.

Deadline for extended abstract and summary: 28 June 2010.

More information Here.

Stormy SPIE

From Mr Tsukemono,

Mr. Tsukemono was sad to see only 4 papers related to Steganography and Steganalysis on the whole conference. The general trend of the decreasing number of papers continues, as WIFS enjoyed only one such paper. But the good news is that the quality of papers was good. And quality is preferred over quantity. 
Mr. Tsukemono has enjoyed following two papers:
  - Application of Viterbi algorithm to asymptotically reach rate distortion bound due to T. Filler, J. Judas and J. Fridrich.  
 - YASS algorithm is finally broken by blind steganalysis, though 1200 features makes Mr. Tsukemono rather bitter.
 Remark: The session was dominated by Binghamton University, from which 3 out of 4 papers came. What are the other groups doing? Are they saving papers for IHW, ACM, WIFS, IWDW, ICIP, ICASP or what else? We should hope.  By considering number of papers and sessions, forget steganography and steganalysis, forensics is the hype now. Forensics was subject of  5 sessions. We could see great papers coming from Dartmouth, Dresden, Binghamton, Purdue, and others. It was not coincidence that 3 papers dealt with the same topic, i.e. how to efficiently search and match fingerprint in large database. Each paper approached the problem from completely different direction. 
Another important point: we could finally see an attempt to plant a new camera fingerprint to the image (and method to detect this forgery).  The watermarking is getting popular as well. The number of accepted papers was so large that the papers had to be presented in parallel sessions. Good for watermarking, bad for conference attendees.  Although tutorial talks this year lacked stunning pictures from deep sea or from deep inside of the human body, they made Mr. Tsukemono a goose flesh. He realized that his new shiny iPhone is spying on him... 

IEEE WIFS'09

Open drum roll. "Ladies and gentlemen, this is the first edition of IEEE Workshop on Information and Security (a.k.a. WIFS). This is the first day of the first edition. This is the first session of the first day of the first edition. This is the first..." Well, this first session will not go down in history, but, this conference was indeed very good:

- a conference theater looking like the "Who wants to be a millionaire" stage (thanks BT!),

- low acceptance ratio,

- high attendee per speaker ratio,

- a good mix of all that matters in information security (watermarking, forensics, traitor tracing, biometrics, steganography, fingerprinting, cryptography...)

- refreshing invited speakers: a judge with subliminal erotic pics (is that what is called the 'french touch'?), a megalo but introspective security expert, and a frightening virus hunter ("Stay away from computers!")

- nasty questions and hot sessions (especially the "We will rock you" traitor tracing speeches), may be too hot since it trigged the fire alarm (thanks BT!).

- the nice playlist in the control booth (thanks BT!).

Miss cucumber back from ye olde London

ACM mmsec 09, the hidden (and fun) parts

By Tsatsiki
Miss cucumber is right, there were interesting papers in the ACM workshop on Multimedia and Security. And the participants had some fun as well. This is mainly thanks to one guy: Scoot Craver, the co-chair of the conference.

Scott is born data-hider, let me tell you why.
Firstly, when the participants arrived to register, they were offered a nice usb key like this one:


- these were the two first hidden messages. (look at it upside down)







Secondly, Scoot launched the workshop saying that there was a hidden (and cyphered) message on the building of the conference (the Friend Center in Princeton). This was true indeed since during the next coffee break the participants were able to see this:

- this was the second hidden message! Did Scoot add the bricks just for the conference? François Cayre, knowing ASCII code by heart, succeeded to decipher the message, while some others asked Google for the solutions.


Of course the talks of the workshop were also filled with hidden information (it was voluntary or not) and two of them were rather fun:
- the magic display cable (Atakli et al.) which is able to recognize, descramble and display encrypted images of a computer desktop on the fly,
- during the rump session, a teaser of the first contest on steganography was presented by T. Pevny. According to him it will be launch in 2010 and called BOSS (for Break Our Steganographic Scheme). I think that this contest is going to be rather popular.

Let's hope that WIFS 2009, the next conference on data-hiding, will be as fun as this one.

ACM mmsec 2009: the rise of the dragon?

ACM mmsec took place under the black and orange flags of the amazing campus of Princeton University, 7-8 september.

The general chair was Ed Felten, Prof. of Computer Science and Public Affairs (might be the only one to have this title), and the director of the brand new Center for Information Technology Policy.

He made a very good introduction speech calling for more discussions between computer scientists and law makers, and then, he almost disappeared from the conference (I could understand, after all, Monday was Labor day)! Never mind, Scott Craver organized a very good social event between nowhere and goodbye in a house near the lake and the lunch in Prospect House was also terrific.

Helas, there were only 40 to 50 attendees! Scott Craver defended the idea that, despite the decline of submissions, their overall quality was good. Therefore, good papers don't fear the financial crisis (if this is the real reason for the submission number decrease).

Like in IH'09, there were indeed quite few papers of lower interest so that the idea of S. Craver holds.

So, what is hot? MP3 quality assessment! The scenario is as follows: a low bitrate MP3 file is transcoded at a higher bitrate and sold as a pretendedly high quality tune. How to detect this? By revealing the signs of a double compression. Actually, H. Farid also presented a talk about double compression to detect video edition. Three speeches, three different approaches: from the "I don't know what happens, but my SVM will tell" heuristic to a more convincing statistical modeling.

The asian dragon? The era of old asian professors reading with difficulty their slides full of approximative english long sentences is over. We are witnessing, in multimedia security (it is probably the case for a long time in other fields), a new generation of young, convincing communicator and quite good researchers. Among the speakers but also in the audience. Some aggressive but very relevant questions were asked.

We also met the future leaders in steganalysis: Jan Kodovsky and Jan Judas replacing the two Tomas evil twins leaving Binghamton (Tomas has already left for Grenoble and soon Praha, while Tomas is finishing his ph.D). The Czech eagle vs. the asian dragon... An interesting battle is coming.

Talks I liked:

- "Two Key Estimation for the Borken Arrows watermarking Scheme", P. Bas and A. Westfeld. Another evil twin couple is born. How to break Broken Arrows (the watermarking technique used for BOWS-2) again and again. I guess, since P. Bas is one of the inventor, it is easier to analyze one's own scheme.

- "Additive Spread-spectrum watermarking detection in demosaicked images", P. Meerwald and A. Uhl. Hack your camera! The Austrian team modified the firmware of a camera so that watermark embedding is done in the device just after the CFA capture. Cool hack! This rises the challenge of watermark detection after demosaicking.

- "Exposing digital forgeries in video by detecting double quantization", W. Wang and H. Farid.

The best paper of all the "double compression" works in this conference. Nice but oversimple talk (as always), which plays the role of a teaser to read the paper for further information. The paper is indeed good: statistical model, identification of the parameters with an 'E-M' like algorithm, hypothesis test.

- "Calibration revisited" J. Kodovsky and J. Fridrich. My understanding about calibration is that natural images follow no statistical model or a so flat pdf p(X) that no hypothesis test will work with so few discrimination. Calibration is about estimating a set of parameters P specializing the model, switching from the flat marginal p(X) to the much more contrasted conditional p(X|P). Calibration is about statistical modeling. Whereas this paper uses calibration with SVM, which is, IMHO, the contrary of statistical modeling. SVM means "I don't know how to model things but, once trained, the SVM will find its way". Therefore, I was a little confused by this approach. But the results are there.

- "Square Root Law" A. Ker. During IH'09, I was not convinced by the talks about the square root law: It is was not enough formalized, the assumptions were not clearly delimited, so that if the law indeed holds, we could not tell the real reasons. This is exactly what Andrew Ker did in between the two conferences, and now, this became serious math with theorem (conditions and results) and proofs.

- "Detection of seam carving and localization of seam insertions an digital images" A. Sarkar, L. Natarj, and B. Manjunath. Seam carving is this image processing tool. It a priori seems a 'mission impossible' to detect seam carving, but a heavy tool (a 324 Markov features classifier) starts producing good results. Work in progress. A maybe too dense presentation.

Miss Cucumber

IEEE DSP 2009

What would you expect from a conference located in a gorgeous place (Santorini, Greece), during summer and with an acceptance rate of 76%?

It was very good (Sea, Sirtaki & Sun), and very bad (security with no secret key, security with no threat analysis,...). So bad? No, so nice invited talk by M. Unser, nice compressed sensing presentations (link with traitor tracing becomes more and more obvious). And what about watermarking? Although there were 5 sessions dealing with multimedia security and forensics, I was quite disappointed in general. Some good presentations:

• Content-Adaptive Semi-Fragile Image Authentication Based on JPEG2000 Compression, M. Schlauweg. The idea of J. Eggers but pushed to a more practical level.
• Blind DT-CWT Domain Additive Spread-Spectrum Watermark Detection, P. Meerwald. The idea of Loo & Kingsbury, but improved to a more practical level. At last, someone no longer uses PSNR for quality assessment. 
  
• Analysis of Denoising Filters for Photo Response Non Uniformity Noise Extraction in Source Camera Identification, I. Amerini. At last, somebody noticed that since PRNU is multiplicative noise, then, linear estimation is not the optimal. Too bad, the correlation is still here.

Miss Cucumber from the tatziki country.

Information Hiding 2009

Information Hiding is one of the oldest workshops on Data Hiding. The 11th edition took place in Darmstadt, June 8-10. The organizers were Stefan Katzenbeisser (TU Darmstadt) and Ahmad Sadeghi (Univ. Bochum).

One third of the papers dealt with Steganography, one third with forensics (active or passive), the others with traitor tracing and exotic applications. This edition faced a low number of submissions, hence, some accepted papers were not so good.

The German community was very impressive and well organized. Several towns/universities clearly carry the label "IT Security" and/or "Multimedia Security" and get huge fundings: Bochum, Darmstadt, Dresden and Magdeburg.

Steganography becomes (at last) a noble science. Papers are more and more theoretical (see Tomas Filler, Andrew Ker or Rainer Bohme very interesting talks). On the contrary, forensics are always very ad-hoc.

The most controversial talk was "Hardware-based public-key cryptography with public physical unclonable functions" by M. Potkonjak. From what I understood: Take a chip implementing a network of XOR gates. The system has w binary inputs, and w outputs. When the input changes from NULL to w-bit message M, many glitches appear at the output before it is stable. Indeed, these astable states of the output depend on the delay of each gate. Therefore, at a given time t (before stability), from one chip to another, the output is very random.

This could be used to identify the chip. But, here, the authors propose to use this for asymmetric cryptography. Basically, Alice publishes the model of her chip (ie. the set of delays). Bob simulates the scenario above thanks to this model. He sends the output C to Alice. Alice has the hardware, she can make a brute force attack to find back M. Eve must software simulate like Bob. Eve must lead a brute force attack like Alice. However, software simulation is much much slower, and a brute force attack is not tractable if the number of gates is big enough. This was quite a controversial talk: "Public key cryptography relies on non-proven conjectures, whereas here, we resort to technological and physical laws preventing the manufacturing of fully identical systems." What a bold statement! No need to say that the cryptos in the room were coughing.

 Miss cucumber, back from Darmstadt