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

“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

Countermeasures The detection of steganographically encoded packages is called steganalysis.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 loss to nation’s integrity. If we misuse it causes great loss to nation’s integrity. Doesn't hide the fact that an e- mail was sent, negating the purpose of secret communications Doesn't hide the fact that an e- mail was sent, negating the purpose of secret communications Someone else with a steganography detection and cracking tool could expose the message Someone else with a steganography detection and cracking tool could expose the message ADVANTAGESDISADVANTAGES 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 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 WATERMARKING DIGITAL WATERMARKING

DEFINITION Digital 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 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 CHARACTERISTICS OF WATERMARKS Robustness Transparency Capacity Low complexity Tamper resistance or tamper evident

DIGITAL WATERMARKING PROCESS The following are the stages involved in watermarking process, Generation of watermark. Embedding stage. Distribution stage. Extraction stage. Decision stage.

GENERAL WATERMARKING PROCESS ORIGINAL IMAGE EMBEDDING ALGORITHM WATERMARKED IMAGE WATERMARK WATERMARK GENERATION ALGORITHM DECISION EXTRACTED WATERMARK EXTRACTION ALGORITHM ATTACK ON WATERMARKED IMAGE

POSSIBLE ATTACKS ON WATERMARKS An 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 compression Geometric transformations 1.Horizontal flip 2.Cropping 3.Scaling 4.Geometric distortions with JPEG

WATERMARKED IMAGEUNWATERMARKED IMAGE WATERMARK 2.VISIBLE WATERMARK 1.INVISIBLE WATERMARK

APPLICATIONS OF WATERMARKING Copyright Protection Fingerprinting Copy Protection Broadcast Monitoring Data Authentication and Integrity Data Hiding or Steganography Image Labeling

CONCLUSIONS: Digital Watermarking moves through nation and creates sensation STEGANOGRAPHY is source for vision 2020 This is basic concept for evolving bubble technology This basic concept prevents piracy in videos This gives the basic concept for white hat hackers

QUERIES ? QUERIES ?