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.
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
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