This document compares watermarking and cryptography. It discusses that watermarking involves hiding secret information in digital images while cryptography transforms information into an unreadable format. Watermarking provides security and an extra layer of authentication while cryptography focuses on protecting the meaning of documents. The document also outlines some advantages and disadvantages of each technique such as watermarking being more resistant to attacks but cryptography providing better security through encryption.

1. SAVEETHA UNIVERSITY
CHENNAI:602105
DEPARTMENT OF ELECTRONICS AND
COMMUNICATION ENGINEERING

2. DONE BY,
POOJA SHUKLA
PRIYANKA RANJAN
SONAM TIWARI

3. • To compare watermarking with cryptography
• To compare the relative advantages and disadvantages
• To provide security needs as well as extra layer of
authentication

4. • Watermarking is a technique for labelling digital pictures by
hiding secret information into the images.
• Cryptography is a scheme of protecting information by
transforming it into an unreadable format.

5. • Cryptography is a secret sharing scheme which
independently disclose no information about the
original secret image
Cryptography can be applied to,
 TEXT
 CODE
 IMAGES

6. • Watermarking uses electronic stamps which is used
for labeling digital pictures by hiding secret
information into the images.
Water Marking can be applied to,
 IMAGES
 TEXT
 AUDIO
 VIDEO

7. ORIGINAL WATERMARKED
IMAGE WATERMARK IMAGE
EMBEDDING INVERSE DWT
DWT
PROCESS

11. WATERMARKING CRYPTOGRAPHY
1. Watermarking is about 1. Cryptography is about
robustness against protecting the meaning of
possible attacks the document
2. Uses steganography 2. Uses biometrics
techniques techniques
3. Gives more privacy 3. No privacy

12. • Undetectable and Undeletable by hackers
• Resistant to lossy data compression
EXAMPLE : JPEG
• Resistant to image manipulation and processing
operations
EXAMPLE : cut-copy-paste
• Privacy
• Security
• Cost and Capacity
• Recoverable and Reversible

13. • Message secure algorithm
• Security parameter
• Secure keying
• Not transmitted to anyone
• Enables use of DIGITAL CERTIFICATES
• Fully automated
• High speed

14. • Copyright protection
• Prevention of unauthorized copying
• Authentication
• Media Bridging
• Broadcast Monitoring
• Fingerprinting
• Secret Communication
• Determination of ownership

15. • Secrecy in transmission and storage
• Integrity in transmission and storage
• Authentication of identity
• Credentialing system
• System using changing key
• Hardware support

16.  Perceptually Invisible
 Robustness
 Embedding Effectiveness
 Data Payload
 Blind and Informed Detection
 High bit rate

17.  Image resistance
 Message authentication codes
 Accessibility
 Cryptokey security
 Protection
 Exportable and Removable
 Unique owner

18. Requirements vary with application. For
example,
Perceptually transparent - must not perceptually
degrade original content.
Robust – survive accidental of malicious attempts
at removal.
Oblivious or Non-oblivious – recoverable with or
without access to original.
Capacity – number of watermark bits embedded.
Efficient encoding and decoding.

19. 1. Embedding Locations
2. Robust Watermarking
3. Fragile Watermarking
4. Semi-Fragile Watermarking
5. Configuration of Cover Work by Watermark
Embedding
6. Watermarking Domains

20. 1. Hash Techniques
2. Symmetric Key Cryptography
3. Asymmetric Key Cryptography

21. DISCRETE FREQUENCY TRANSFORM
DISCRETE COSINE TRANSFORM
DISCRETE WAVELET TRANSFORM

22. • PSNR
• SNR
• Transformation Method
• Image Format
• Quality Factor
• Kemel size
• Security Parameter
• Embedding Parameter
• Detection Parameter

27.  Detecting and decoding the hidden data within a given
medium.
 Even if secret content is not revealed, modifying the
cover medium changes the medium’s statistical
properties.
 Distributed Dictionary Attack
 It deals with possible attacks and protects the
content.
 Once you try to hack the secret the whole content
gets destroy.

28. The most important use of
CRYPTOGRAPHY techniques will probably
lie in the field of digital watermarking.
It may become limited under laws -
governments claimed that criminals use
CRYPTOGRAPHY AND WATERMARKING to
communicate.

29. • Independent watermarking classification by
Dittmann, J., Mukherjee, A., & Steinebach, M. (2000,
March 27 - 29).
• Applied cryptography by Wiley and Sons, 1996.

30. • Hidden Digital Watermarks in Images by Chiou-Ting
Hsu and Ja-Ling Wu, Senior Member, IEEE
• A Feature-Based Robust Digital Image Watermarking
Scheme by Chih-Wei Tang and Hsueh-Ming Hang,
Fellow, IEEE
• Comparison Of Visual Cryptography Schemes by M.
Amarnath Reddy, IJEST