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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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Digital Watermarking

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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

Digital watermarking

Steganography


Introduction

Digital watermarking

Relation between embedded message and cover work

Goal and assumption

Steganography


Content

  • Introduction

  • History

  • Applications

  • Requirements

  • Techniques

  • Attacks


History

Fabriano

Histiæus & the slave

Paper watermark, 1282

Banknote. 18th century


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


Content

  • Introduction

  • History

  • Applications

  • Requirements

  • Techniques

  • Attacks


Applications

  • Broadcast monitoring

  • Owner identification

  • Proof of ownership

  • Transaction tracking

  • Content authentication

  • Copy control


Broadcast monitoring

Advertisement

Rebroadcasting


Owner identification

Original

Lena Soderberg, 1972


Proof of ownership

Bob

Alice


Transaction tracking


Transaction tracking


Content authentication

  • Digital signature is NOT enough


Content authentication


Copy control

  • Cryptography is NOT enough


Copy control


Content

  • Introduction

  • History

  • Applications

  • Requirements

  • Techniques

  • Attacks


Requirements

  • Perceptual Transparency

  • Robustness

  • Data payload

  • With / Without originals

  • Security


Perceptual Transparency


Robustness

  • Fragile

  • Semi-fragile

  • Robust


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

  • Non-blind watermarking

    • Type I

    • Type II

  • Semi-blind watermarking

  • Blind watermarking


Security

(Present later)


The mutual dependencies among the elements


Content

  • Introduction

  • History

  • Applications

  • Requirements

  • Techniques

  • Attacks


Techniques

  • LSB

  • Spread spectrum

  • Applying on Vietnamese documents


Techniques


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, …)


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


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


Techniques

  • LSB:

    • Detector:

      • Retrieve the watermark by having the knowledge of the representation values (e.g pixels) used for embedding individuals bits


Techniques

  • Spread spectrum

    • Using frequency domain transform to convert the input image into another domain and embedding the watermark to this domain.


Techniques

  • Apply on Vietnamese documents


Techniques

  • Apply on Vietnamese documents


Techniques

  • Apply on Vietnamese documents

    • Besides, we can use some methods:

      • Vertically shifting text lines

      • Horrizontally shifting words


Content

  • Introduction

  • History

  • Applications

  • Requirements

  • Techniques

  • Attacks


Attacks

  • From processing

  • From attackers


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


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.


Attacks


Attacks

Mosaic attack


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. “


Questions & Answers

Thank you


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