1. Chair Professor Chin-Chen Chang Feng Chia University
Security Technologies on Communication Networks and Their Applications to Electronic Business
Chair Professor Chin-Chen Chang
Feng Chia University
National Chung Cheng University
National Tsing Hua University

2. Outline Mobile services Radio Frequency Identification (RFID)
Roaming between cellular network and WLAN
Watermarking
Image authentication
Visual cryptography
Secret sharing
Steganography
MSN lab

3. Mobile services (1/4)
MSN lab

4. Mobile services (2/4)
MSN lab

5. Mobile services (3/4)
MSN lab

6. Treats ? (4/4) User perspective Network perspective Spoofing Framing
Denial-of-service
Network perspective
Passive
Active
1. Eavesdropping
2. Traffic analysis
1. Masquerading
2. Replay
3. Message modification
MSN lab

7. Spoofing
MSN lab

8. Framing
Legitimate?
Bogus?
MSN lab

9. Denial-of-service
MSN lab

10. RFID (1/4)
Tag
Reader
Database
Antenna
MSN lab

11. RFID (2/4) Shopping Library Transportation Household appliance …
MSN lab

12. Risk? (3/4) Eavesdropping Traffic analysis Replay attack
Position detection
Physical attack
MSN lab

13. Issue? (4/4) Anonymity -> Privacy Synchronization Authentication
Efficiency
MSN lab

14. Roaming (1/3) Access to the Internet anywhere & anytime
Mobile device
Base station AP AS
ISP WLAN
Cellular network
AS: Authentication server
AP: Access point
MSN lab

15. Roaming (2/3)
Cellular networks : wide service areas and continuous pervasive access
WLAN : high-speed pervasive communications
How to integrate?
MSN lab

16. Issues? (3/3)
Mutual authentication
Anonymous service
Charging
MSN lab

17. Watermarking Visible watermarking Easy to embed Clear to see watermark
MSN lab

18. Watermarking (Cont.) Invisible watermarking Requirements:
Good visual quality of watermarked image
Robustness
Watermarking
Original image
Watermarked image
MSN lab
Watermark

19. Image authentication Requirements: Detect the tampered area
Try to restore the tampered area
Image
Tampered image
Detected image
Restored image
MSN lab

20. Classification: Meaningless shadows Meaningful shadows Secret sharing
MSN lab

21. Secret sharing (Cont.) Sharing Shadow size: 256  256 Reconstructing
Image size: 512  512
Reconstructing
(2,4)-threshold secret
sharing scheme
MSN lab
PSNR=24 dB

22. Secret sharing (Cont.) Reconstructing Secret image Hiding Stego-image
Reconstructed secret image
Secret image
Stego-image
(2, n)-threshold secret
sharing scheme
Stego-image
MSN lab

23. Visual cryptography
Stacking
Shadow 1
Shadow 2
Secret
MSN lab

24. Visual cryptography (Cont.)
Stacking
Shadow 1
Shadow 2
MSN lab
Secret

25. Visual cryptography (Cont.)
Rotating 40o
Stacking
Stacking
Share 1
Share 2
Secret 1 “VISUAL”
Secret 2 “SECRET”
MSN lab

26. Steganography The targets Restoration
Frequency domain (e.g. DCT, DWT, DFT)
Spatial domain (e.g. pixel values)
Compression domain (e.g. VQ)
Text
Restoration
Irreversible
Reversible
MSN lab

27. Steganography (Cont.) Image Hiding system Stego image Cover image
Secret message
Stego image
MSN lab

28. Steganography (Cont.) Text Video Sound 壞的毛病 壞毛病 山東的蘋果 山東蘋果 我的媽媽 我媽媽
壞的毛病 壞毛病
山東的蘋果 山東蘋果
我的媽媽 我媽媽
主要的問題 主要問題
另外的一件事 另外一件事
其他的問題 其他問題
北京的大學 北京大學
Video
Sound
MSN lab

29. Conclusions The biggest risk: eavesdropping & copy The limitation:
Power
Computing capability
Robustness
Image quality
MSN lab

30. Security Technologies on Communication Networks and Their Applications to Electronic Business
MSN lab