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Digital Watermarking. Thái Chí Minh Trần Lương Khiêm. Content. Introduction History Applications Requirements Techniques Attacks. Content. Introduction History Applications Requirements Techniques Attacks. Introduction. 499.99 = 0.99. Introduction. Introduction.

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Presentation Transcript
slide1
Digital

Watermarking

Thái Chí Minh

Trần Lương Khiêm

content
Content
  • Introduction
  • History
  • Applications
  • Requirements
  • Techniques
  • Attacks
content1
Content
  • Introduction
  • History
  • Applications
  • Requirements
  • Techniques
  • Attacks
introduction
Introduction

499.99 = 0.99

introduction2
Introduction

Digital watermarking

Steganography

introduction3
Introduction

Digital watermarking

Relation between embedded message and cover work

Goal and assumption

Steganography

content2
Content
  • Introduction
  • History
  • Applications
  • Requirements
  • Techniques
  • Attacks
history
History

Fabriano

Histiæus & the slave

Paper watermark, 1282

Banknote. 18th century

history1
History
  • In 1954, Emil Hembrooke of the Muzak Corporation filed a patent for watermarking” musical Works
  • The first Information Hiding Workshop (IHW) ,which included digital watermarking as one of its primary topics, was held in 1996
content3
Content
  • Introduction
  • History
  • Applications
  • Requirements
  • Techniques
  • Attacks
applications
Applications
  • Broadcast monitoring
  • Owner identification
  • Proof of ownership
  • Transaction tracking
  • Content authentication
  • Copy control
broadcast monitoring
Broadcast monitoring

Advertisement

Rebroadcasting

owner identification
Owner identification

Original

Lena Soderberg, 1972

content authentication
Content authentication
  • Digital signature is NOT enough
copy control
Copy control
  • Cryptography is NOT enough
content4
Content
  • Introduction
  • History
  • Applications
  • Requirements
  • Techniques
  • Attacks
requirements
Requirements
  • Perceptual Transparency
  • Robustness
  • Data payload
  • With / Without originals
  • Security
robustness
Robustness
  • Fragile
  • Semi-fragile
  • Robust
data payload
Data payload
  • Data payload refers to the number of bits a watermark encodes within a unit of time or within a Work
  • Different applications may require very different data payloads
with without originals
With / Without originals
  • Non-blind watermarking
    • Type I
    • Type II
  • Semi-blind watermarking
  • Blind watermarking
security
Security

(Present later)

content5
Content
  • Introduction
  • History
  • Applications
  • Requirements
  • Techniques
  • Attacks
techniques
Techniques
  • LSB
  • Spread spectrum
  • Applying on Vietnamese documents
techniques2
Techniques
  • There are many techniques to do watermarking in digital things:
    • Spatial domain watermarking: LSB, in text data, …
    • Transform domain watermarking: frequency-based watermarking, wavelet based watermarking
      • Embedding the watermark in the transform domain from carrier object (using DCT, DFT, DWT, …)
techniques3
Techniques
  • LSB:
    • Embedding:
      • Choosing some representation values (e.g pixels) of carrier object.
      • Embed the bits of message (watermark) to LSBs of representation value
        • Message ‘A’: 100 0001
        • Carrier object: RGB (2 bits)

100000 010101 101100

010001 100001 000100

101110 011010 111000

techniques4
Techniques
  • LSB:
    • Embedding:
      • Choosing some representation values (e.g pixels) of carrier object.
      • Embed the bits of message (watermark) to LSBs of representation value
        • Message ‘A’: 100 0001
        • Carrier object: RGB (2 bits)

100001 010100 101100

010000 100001 000100

101111 011010 111000

techniques5
Techniques
  • LSB:
    • Detector:
      • Retrieve the watermark by having the knowledge of the representation values (e.g pixels) used for embedding individuals bits
techniques6
Techniques
  • Spread spectrum
    • Using frequency domain transform to convert the input image into another domain and embedding the watermark to this domain.
techniques7
Techniques
  • Apply on Vietnamese documents
techniques8
Techniques
  • Apply on Vietnamese documents
techniques9
Techniques
  • Apply on Vietnamese documents
    • Besides, we can use some methods:
      • Vertically shifting text lines
      • Horrizontally shifting words
content6
Content
  • Introduction
  • History
  • Applications
  • Requirements
  • Techniques
  • Attacks
attacks
Attacks
  • From processing
  • From attackers
attacks1
Attacks
  • The actions take effect on the watermark embedded in carrier objects.
    • Affects:
      • Destroying the watermark or modifying the watermark with new wrong information.
      • Removing the watermark entirely.
    • But: not degrading the quality of carrier objects (image, audio, video)
    • Relating to a requirements of watermarking: Robustness
attacks2
Attacks
  • Classification:
    • From proscessing carrier objects
      • Common signal processing: digital-to-analog and analog-to-digital conversion, or change image contrast, color, JPEG compression, …
      • Common geometric distortions: scaling, rotating, cropping, dithering …
    • From attacker
      • Mosaic
      • Collusion attacks: get the watermark or remove watermarks entirely to get the original work.
attacks4
Attacks

Mosaic attack

attacks5
Attacks
  • How to protect watermarks from attacks
    • Understanding and applying new researchs in watermarking
    • Using StirMarkBenchmark evaluation engine to evaluate your watermarking scheme
      • “All vendors of digital watermarks have their products benchmarked by Stirmark and as of August 2001, no watermark from any vendor survives the test, ie: the watermarks are all removed without degradation to image quality occurring. “
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