Institute of Information Science, Academia Sinica



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CITI--Information theoretic security: from post-quantum to multimedia

  • LecturerDr. Shih-Chun Lin (National Tsing-Hua University)
    Host: Prof. Wei-Ho Chung
  • Time2011-01-28 (Fri.) 10:30 – 12:00
  • LocationAuditorium 106 at new IIS Building




Network information theory was proved to be a powerful tool 
to design reliable transmissions in multiuser channels. Recently, 
network information theory has been applied to information security 
problems including secrecy in post-quantum era and protecting 
copyrighted multimedia. The so-called “information theoretic 
security” is among the hottest topics in research society nowadays. 
The first part of this talk focuses on the application of information 
theoretic security on post-quantum confidentiality problem. We 
consider the transmission of confidential messages over the wireless 
channels subjecting to eavesdropping by terminals within the 
transmission range. Conventionally, the confidentiality is assured 
by cryptographic systems which are only computationally secure, and 
will eventually become insecure when quantum computers or other even 
more powerful computing techniques are mature. Thus we consider the 
worst case scenario that the eavesdropper can perform attacks with 
unlimited computations. One promising method to guarantee 
confidentiality is combining secure coding and artificial-noise 
assisted beam forming.
We study the impacts of quantized channel feedback on the performance 
of this method. As first appeared in the literature, we identify the 
important role of the artificial noise leakage problem, and propose 
methods to combat it. The asymptotic analysis shows that without 
proposed system designs, the secrecy rate loss may approach infinity 
due to the artificial noise leakage problem.
The second part of this talk focuses on the application of information 
theoretic security on the multimedia fingerprinting problem. Digital 
fingerprinting is a technique to protect copyrighted data against 
illegal distribution. A powerful attack to break the digital 
fingerprinted system is that several users may collude to form a 
coalition, enabling them to produce an unauthorized copy which is 
difficult to trace the colluders. We adopt an information theoretic 
framework for the design of collusion-resistant coding and decoding 
(identification of colluders) schemes for digital fingerprinting. 
We found out that the code design for digital fingerprinting is 
closely related to that for multiple-access channel. Based on this 
relationship, two practical fingerprinting codes tailored for 
different collusion attacks was proposed, and both can respectively 
protect the largest number of licensed users in literatures.
Bio: Shih-Chun Lin received the B.S. and Ph.D. degrees in electrical 
engineering from National Taiwan University, Taipei, Taiwan, in 2000 
and 2007, respectively. He was a Visiting Student at The Ohio State 
University, Columbus, in 2007, hosted by Professor Hesham El Gamal 
(IEEE Fellow). After serving his military duty in 2008, Dr. Lin is 
a postdoctoral research associate at the Institute of Communications 
Engineering, National Tsing-Hua University, Hsinchu, Taiwan now. He 
also served as a TPC member of IEEE VTC 2010-Spring. His research 
interests include coding/information theory, communications, and 
signal processing.