Top Banner
CYBER SECURITY BITS EDU CAMPUS COMPUTER SCIENCE DEPARTMENT
13

Steganography ppt

Apr 13, 2017

Download

Engineering

Taha Malampatti
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Steganography ppt

CYBER SECURITYBITS EDU CAMPUS

COMPUTER SCIENCE DEPARTMENT

Page 2: Steganography ppt

TOPIC:

STEGANOGRAPHY

Prepared by:

Shruti Ghelani-140050107031

Taha Malampattiwala-140050107052

Jinal Mayavanshi-140050107056

Page 3: Steganography ppt

INFORMATION HIDING• Information Hiding is a branch of computer science that deals with

concealing the existence of a message• It is related to cryptography whose intent is to render messages

unreadable except by the intended recipients• It employs technologies from numerous science disciplines:

• Digital Signal Processing (Images, Audio, Video)• Cryptography• Information Theory\Coding Theory• Data Compression• Human Visual/Auditory perception

• There are four primary sub-disciplines of Information Hiding• Steganography• Watermarking• Covert Channels• Anonymity

Page 4: Steganography ppt

• Alice and Bob• Classical names given to the parties wishing to communicate

• Sometimes, you may have a Carol and a Dave

• Eve, an adversary, can listen to but not modify or forge a message• (think passive eavesdropping)

• Wendy the Warden, another adversary, can monitor, modify, or forge a message• A passive warden simply listens (like Eve)

• An active warden may modify a message

• A malicious warden may forge a fake message

BASIC TERMINOLOGY

Page 5: Steganography ppt

What is Steganography?

def’n: the art and science of hiding information by embedding it in some other data.

cryptography - render message unintelligiblesteganography - conceal the existence of the message

Page 6: Steganography ppt

• Steganography literally means “covered writing”• A stegosaurus has a covered back

• Steganography’s primary goal is to hide data within some other data such that the hidden data cannot be detected even if it is being sought

• Secondary goals:• prevent extraction from the cover file without destroying the cover• prevent destruction of the stego-message without destroying the cover

• Most frequently, steganography is applied to images, but many other data or file types are possible• Audio• Video• Text• Executable programs

Page 7: Steganography ppt

The cover provides a host for transporting the hidden info.

info

embed

-file

extract

info

Page 8: Steganography ppt

Digital Steganography

• HTML message as cover?

• computer program as cover?

• network protocol headers

• white space in text

• unused space in buffer

• least significant bits of image

• slight distortion in sound file

• “Easter eggs”

Page 9: Steganography ppt

Steganography in ImagesTwo types of compression: • lossless (gif) • lossy (jpeg)

Sometimes concealed message inserted as a comment.Sometimes the accuracy of the image is sacrificed slightly.

Common Tools• StegoDOS

• White Noise Storm

• S-tools• Outguess• Steghide

Page 10: Steganography ppt

APPLICATIONS OF INFORMATION HIDING• Covert military communications

• Covert police communications• Criminals have learned that police are nearby when they hear encrypted

communications, so they abate their activity for the moment

• A steganographic system would prevent this detection

• Digital Rights Management – protecting intellectual property such as images, music, electronic books, etc.

• Embedding textual data in medical images would better ensure that the picture belongs to a particular patient• This technique could apply to personal pictures, sounds, and movies

• Tamper proofing – ensuring a data file has not been changed

• Communicating in an oppressive country w/o free speech

Page 11: Steganography ppt

NEFARIOUS APPLICATIONS OF INFORMATION HIDING

• You won’t find these applications in the book• money laundering• drug running• child pornography• spying (good or bad depending upon which side you’re on!)• terrorism

• Unfortunately, these uses are also possible• The technology itself isn’t bad, but like many things, it can be (and is)

abused• Since there are nefarious uses, law enforcement and the military is also

interested in understanding hiding techniques and detecting hidden data• There are some projects right here at UTSA that have done research for the

Air Force

Page 12: Steganography ppt

STEGANALYSIS• Steganalysis is the detection of data that has been hidden

• It is a cat and mouse game – as one group of researchers come up with better ways to hide stuff, another group figures out how to detect it or perhaps just destroy it

• In the summer course last year, one student thought he had a hiding system that was undetectable

• His lab partner wrote a statistical analysis program that exposed the hidden message

• The first student modified his program to defeat the attack

• His lab partner modified his analyzer and still found the message

Page 13: Steganography ppt

THANK YOU.