STEGANOGRAPHY AND

DIGITAL WATERMARKING

KAKATIYA INSTITUTE OF TECHNOLOGY AND SCIENCES,WARANGAL

COPY RIGHTS: Copyrights are the rights of an author

or creator to control the reproduction of their own intellectual property

COPYRIGHTS PROTECTION 1. Steganography 2. Digital Watermarking 3. Cryptography etc.,

WHY FOR STEGANOGRAPHY!

WHAT IS STEGANOGRAPHY?

HOW WITH STEGANOGRAPHY!

DEFINITION:DEFINITION:

• Steganography is derived from the Greek name “steganos” (hidden or secret) and “graphy” (writing or drawing) and literally means hidden writing

• Steganography is the art and science of writing hidden messages in such a way that no one apart from the intended recipient knows of the existence of the message .

HISTORICAL STEGANOGRAPHIC HISTORICAL STEGANOGRAPHIC TECHNIQUESTECHNIQUESHidden messages in wax tablets: in ancient

Greece, people wrote messages on the wood, then covered it with wax so that it looked like an ordinary, unused, tablet.

kings would shave the heads of slaves and tattoo important messages on their scalps. Then, hair was allowed to grow back and slaves would carry messages without anyone suspecting any kind of communication

Other private codes used invisible ink. This would dry up after the message was written and would not be visible until it was exposed to heat

MODERN STEGANOGRAPHIC MODERN STEGANOGRAPHIC TECHNIQUESTECHNIQUES

Steganography in TEXT FILES

Steganography in AUDIO FILES

Steganography in IMAGE FILES

Assume the original three pixels are represented by the three 24-bit words below:

(00100111 11101001 11001000) (00100111 11001000 11101001) (11001000 00100111 11101001)

The binary value for the letter A is (10000011). Inserting the binary value of A into the three pixels, starting from the left byte, would result in:

(00100111 11101000 11001000) (00100110 11001000 11101000) (11001001 00100111 11101001)

“After the theater, all clients keep a tab down at Wesley’s Nook.”

by taking first letter from each word, we get…

ATTACK AT DAWN

CountermeasuresCountermeasuresThe detection of steganographically

encoded packages is called steganalysis. The simplest method to detect modified

files, however, is to compare them to the originals.

To detect information being moved through the graphics on a website, for example, an analyst can maintain known-clean copies of these materials and compare them against the current contents of the site. The differences (assuming the carrier is the same) will compose the payload (the hidden message).

ADVANTAGES DISADVANTAGES•If we misuse it causes great If we misuse it causes great loss to nation’s integrity.loss to nation’s integrity.

•Doesn't hide the fact that an e-Doesn't hide the fact that an e-mail was sent, negating the mail was sent, negating the purpose of secret purpose of secret communications communications

•Someone else with a Someone else with a steganography detection and steganography detection and cracking tool could expose the cracking tool could expose the message message

ADVANTAGES DISADVANTAGES

•Used to combine explanatory information with an image

•If we misuse it causes great loss to nation’s integrity.

•Peer to peer private communications

•Doesn’t hide the fact that an e-mail was sent , negating the purpose of secret communications.

•Posting secret communications on the web to avoid transmissions.

•Someone else with a steganography detection and cracking tool could expose the message.

DIGITAL DIGITAL WATERMARKINGWATERMARKING

DEFINITIONDEFINITIONDigital watermarking is the process of

inserting a digital signal or pattern (indicative of the owner of the content) into the digital content. The signal, known as watermark, can be used later to identify the owner of the work.

CLASSIFICATION OF DIGITAL CLASSIFICATION OF DIGITAL WATERMARKS WATERMARKS

Visibility of watermarks (1) Visible watermarks. (2) Invisible watermarks.Watermark Extraction. Fragile , semi-fragile or robust.Based on construction (1) Spatial –high quality pixels but not

robust. (2) spectrum-incorporated into the

image‘s transform coefficients

DESIRABLE DESIRABLE CHARACTERISTICS OF CHARACTERISTICS OF WATERMARKSWATERMARKS

Robustness TransparencyCapacityLow complexityTamper resistance or tamper evident

DIGITAL WATERMARKING DIGITAL WATERMARKING PROCESSPROCESSThe following are the stages involved in

watermarking process,Generation of watermark .Embedding stage.Distribution stage.Extraction stage.Decision stage.

GENERAL WATERMARKING GENERAL WATERMARKING PROCESSPROCESS

ORIGINAL IMAGE

EMBEDDING ALGORITHM

WATERMARKED IMAGE

WATERMARK

WATERMARK GENERATIO

N ALGORITHM

DECISIONEXTRACTED WATERMAR

K

EXTRACTION ALGORITHM

ATTACK ON WATERMARKE

D IMAGE

POSSIBLE ATTACKS ON POSSIBLE ATTACKS ON WATERMARKSWATERMARKSAn attack on a watermark can be defined

as an operation, coincidental or hostile, that may degrade a watermark and possibly make it unreliably detectable.

CLASSIFICATIONS: JPEG compressionGeometric transformations  1.Horizontal flip 

2.Cropping 3.Scaling

4.Geometric distortions with JPEG

WATERMARKED IMAGE

UNWATERMARKED IMAGE

WATERMARK

2.VISIBLE WATERMARK

1.INVISIBLE WATERMARK

APPLICATIONS OF APPLICATIONS OF WATERMARKINGWATERMARKING

Copyright Protection Fingerprinting Copy Protection Broadcast Monitoring Data Authentication and IntegrityData Hiding or Steganography Image Labeling

CONCLUSIONS:CONCLUSIONS:Digital Watermarking moves through

nation and creates sensationSTEGANOGRAPHY is source for vision

2020This is basic concept for evolving

bubble technologyThis basic concept prevents piracy in

videosThis gives the basic concept for white

hat hackers

QUERIESQUERIES ??