Bo XIAO
Research Assistant
Lab of New Generation Network
Department of Electronic Engineering
Tsinghua University

Room 9-327, East Main Building
Tsinghua University
Beijing 100084, P.R. China
Tel: +86-10-62792710
Cell: +86-13521888750
skype: bob_xiaobo
E-mail:

Master Candidate
New Generation Network Lab
Department of Electronic Engineering
Tsinghua University
Advisor: Prof. Yongfeng Huang
GPA: 90.0/100

• Research on information hiding communication system based on streaming media (e.g. VoIP)
• Design and Implementation of VoIP softphone based on SIP supporting IPv4/IPv6 on Windows OS using VC 2005

• Support: National Science Foundation of China (NSFC) / National High Technology Development Program of China


• Optimized Information Hiding in Low Bit-rate Speech:
  Traditional QIM(Quantization Index Modulation) embedding divided the codebook into 2 parts, each labeled '0' and '1', but overlooked the way of partition, which may introduce intolerable distortion in case the partition is not proper.
  
  In our work we used Graph Theory to prove that it is always feasible to guarantee that every codeword is partitioned into the opposite group of its nearest neighbor.
  As the result, we find a minimum bound of maximum distortion in data embedding.


• Covert Communication System of Information hiding over VoIP:
  Layered structure is designed for adaption to diverse embedding algorithms, carriers, speech codec and functions.
  The layer over TCP/IP application layer is called Execution and Adaption, whose function is actual embedding into VoIP data and extraction from received data.
  The second layer is called Transmission Management, whose function is to guarantee the accurate secret data transmission and provide interface for application.
  The top layer is called Information Hiding Application, whose function is providing useful application based on the covert communication.
  
  Specific protocol is design for secret message retransmission in transmission management layer, using ARQ-like scheme.
  The carrier is not reused. Instead, the secret message frame is re-embedded in new coming voice data.


• Improved Reversible Data Hiding in Image:
  Traditional Histogram Shifting algorithm was carried out in the whole image. This method desires the histogram to be concentrated with a sharp peak.
  
  Considering the locally correlated nature of image, the total capacity is enlarged if the shifting is carried out in every small block rather than the whole image. However, some blocks may not available for embedding, or change into unavailable after embedding, making the receiver unable to find which blocks are used in carrying messages.
  
  To address this problem, a scheme of capacity reserving is designed to provide the information of the blocks to receiver. Though such information increases overhead bookkeeping, the real capacity is increased 2 to 5 times due to embedding in small blocks.


• Other works in the team:
  Information Hiding in RTP/RTCP protocols
  Detection of Information Hiding in middle bit-rate speech stream

• Xiao Bo, Huang Yongfeng, Shanyu Tang. An Approach to Information Hiding in Low Bit-rate Speech Stream. IEEE Global Communications Conference (GLOBECOM'08), New Orleans, USA, Dec. 2008.

• Xiao Bo, Huang Yongfeng. Modeling and optimizing of the information hiding communication system over streaming media. Journal of Xidian University (Natural Science). 2008 Vol.35, No.3, P.554-558. (In Chinese)

GRE: 530(V)+800(Q)+4.5(AW), TOEFL: 28(R)+28(L)+22(S)+25(W)=103

Swimming, Table tennis, Reading History/Novel, Chinese poem, Movie

Yang CHEN (Ph.D student at Tsinghua University)
Xiaohan Zhao (Master student at NGN Lab, Tsinghua University)