Commutative Encryption and Watermarking in Video Compression

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Commutative Encryption and Watermarking in Video

Compression

Ieee Transactions On Circuits And Systems For Video Technology, Vol. 17, No. 6, June 2007

Shiguo Lian, Member, IEEE, Zhongxuan Liu, Member, IEEE, Zhen Ren, and Haila Wang

Adviser: Chih-Hung LinSpeaker:Tzu-Hsun Liao

Author Shiguo Lian

In 2004, he was a research assistant in City University of Hong Kong

Shiguo Lian got his Ph.D degree in multimedia security from Nanjing University of Science and Technology in July 2005

He has been with France Telecom R&D Beijing since July 2005.

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Author

Zhongxuan Liu Current : Researcher at Orange Education : Shandong University

2007-2008

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Author

Zhen Ren From 1983 to 1986 and 1989 to 1995, she worked as

a Design Engineer at Beijing Institute of Radio Measurement in China.

rom 1995 to 1997, she worked at Glocom Inc, USA, where she was a Design Engineer and involved in several projects that were related to satellite communication terminals

Since 1997, she has been with Intelligent Automation, Inc (IAI), USA, where she is currently a Senior Electronic Engineer

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Author

Haila Wang Current :CEO France Telecom R&D

Beijing Education: Ecole polytechnique 1980-

1983

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Outline

1. Introduction2. Proposed watermarking and

encryption scheme3. Performance analysis4. Conclusions and future work

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1. Introduction Video encryption and watermarking scheme

based on H.264/AVC codec

Intra-prediction mode(IPM), Motion vector difference(MVD) and residue coefficient’s sign are encrypted

Amplitude of dc or ac is watermarked(4*4 DCT Block)

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2 .Proposed watermarking and encryption scheme

Y:encrypted Y’: are the encrypted copy of

YE():encryption algorithm Ke: encryption key

Z:watermarkedZ’: watermarked copy of ZW():watermark algorithmB: watermarkKw:watermark key

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2 .Proposed watermarking and encryption scheme

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2 .Proposed watermarking and encryption scheme

Proposed Encryption Process• MVD Encryption

• IPM Encryption

• Residue Encryption

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2 .Proposed watermarking and encryption scheme

MVD Encryption

X:For each Macroblock the sign is 0-positiveY:For each Macroblock the sign is 1-nonpositiveX’ & Y’:are the encrypted copy of X & Y

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2 .Proposed watermarking and encryption scheme

IPM Encryption

0 0 0 1101

M Zero Mbits

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2 .Proposed watermarking and encryption scheme

Residue Encryption For each non-zero residue macroblock,DCT

coefficients are encrypted partially For each 4*4 DCT block is only first 8

coefficients are encrypted

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2 .Proposed watermarking and encryption scheme

Proposed Watermarking Process• Block Selection

• Coefficient Selection

• Watermark Embedding

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2 .Proposed watermarking and encryption scheme

Block Selection The residue block is nonzero

For I/P-frame, the residue DCT block is composed of only ac’s

For B-frame, the residue DCT block is composed of either dc’s or ac’s

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2 .Proposed watermarking and encryption scheme

Coefficient Selection In middle frequency, M coefficients

are selected randomly from the 8 ones proposed in residue encryption

0<M≤8

middle frequency(4*4DCT Block)

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2 .Proposed watermarking and encryption scheme

Watermark Embedding

W:watermark Z: original coefficientZ’: watermarked coefficientq: quantization stepSign:+ or -

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2 .Proposed watermarking and encryption scheme

Watermark Embedding

W:watermark Z: original coefficientZ’: watermarked coefficientq: quantization stepSign:+ or -

2 .Proposed watermarking and encryption scheme

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2 .Proposed watermarking and encryption scheme

Watermark Extraction

W:watermark Z: coefficientq: quantization step

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3. Performance analysis

Security• Cryptographic Security

• Perception Security

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3. Performance analysis

Cryptographic Security 128-bit AES cipher is used to encrypt

the selected parameters

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3. Performance analysis

Perception Security(a). Original

(b). IPM

(c). MVD

(d). Encrypted with the proposed method

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3. Performance analysis

Perception Security

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3. Performance analysis

Robustness and Imperceptibility

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3. Performance analysis

Robustness and Imperceptibility

Salesman-QCIF/30 fps

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3. Performance analysis

Commutation

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3. Performance analysis

Commutation

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Conclusions and future work

The modified watermarking algorithm makes the watermarking operation and encryption operation commutative

The scheme keeps secure against present attacks, is efficient in implementation, keeps imperceptible, and is robust against recompression in some extent