STEGANOGRAPHY-SWAPNIL BANGERA

ME-EXTC

THE ART OF WAR TEACHES US TO RELY NOT ON THE LIKELIHOOD OF THE ENEMY’S NOT COMING, BUT ON OUR OWN READINESS TO RECEIVE HIM; NOT ON THE CHANCE OF HIS NOT ATTACKING, BUT RATHER ON THE FACT THAT WE HAVE MADE OUR POSITION UNASSAILABLE.

-THE ART OF WAR, SUN TZU

NETWORK SECURITY

THE FIELD OF NETWORK SECURITY CONSISTS OF MEASURES TO DETER, PREVENT, DETECT, AND CORRECT SECURITY VIOLATIONS THAT INVOLVE THE TRANSMISSION OF INFORMATION.COMPUTER SECURITY IS THE PROTECTION AFFORDED TO AN AUTOMATED INFORMATION SYSTEM IN ORDER TO ATTAIN THE APPLICABLE OBJECTIVES OF PRESERVING THE INTEGRITY, AVAILABILITY , AND CONFIDENTIALITY OF INFORMATION SYSTEM RESOURCES.

TYPES OF NETWORK SECURITY

•CRYPTOGRAPHY•STEGANOGRAPHY

CRYPTOGRAPHY

• CRYPTOGRAPHY IS A METHOD OF STORING AND TRANSMITTING DATA IN A PARTICULAR FORM SO THAT ONLY THOSE FOR WHOM IT IS INTENDED CAN READ AND PROCESS IT.• THE MESSAGE ENCRYPTED USING CRYPTOGRAPHY HAVE NO MEANING

UNLESS SOMEONE HAS A PROPER KEY TO DECODE IT.

STEGANOGRAPHY• STEGANOGRAPHY IS THE PRACTICE OF CONCEALING A FILE, MESSAGE, IMAGE, OR

VIDEO WITHIN ANOTHER FILE, MESSAGE, IMAGE, OR VIDEO.• THE WORD STEGANOGRAPHY COMBINES THE GREEK WORD STEGANOS, MEANING

“COVERED, CONCEALED, OR PROTECTED”, AND GRAPHIEN MEANING “WRITING”.• THE GOAL OF STEGANOGRAPHY IS TO HIDE MESSAGES IN SUCH A WAY THAT NO ONE

APART FROM THE INTENDED RECIPIENT EVEN KNOWS THAT A MESSAGE HAS BEEN SENT.• THIS CAN BE ACHIEVED BY CONCEALING THE EXISTENCE OF INFORMATION WITHIN

SEEMINGLY HARMLESS CARRIERS OR COVERS.

EXAMPLE

SINCE EVERYONE CAN READ, ENCODING TEXT IN NEUTRAL SENTENCESS IS DOUBTFULLY EFFECTIVE

SINCE EVERYONE CAN READ, ENCODING TEXTIN NEUTRAL SENTENCES IS DOUBTFULLY EFFECTIVE

3RD MARCHDEAR GEORGE,

GREETINGS TO ALL AT OXFORD,. MANY THANKS FOR YOUR LETTER AND FOR THE SUMMER EXAMINATION PACKAGE. ALL ENTRY FORMS AND FEES FORMS SHOULD BE READY FOR FINAL DISPATCH TO THE SYNDICATE BY FRIDAY 20TH OR AT THE VERY LATEST, I’M TOLD BY THE 21ST. ADMIN HAS IMPROVED HERE, THOUGH THERE’S ROOM FOR IMPROVEMENT STILL; JUST GIVE US ALL TWO OR THREE MORE YEARS AND WE’LL REALLY SHOW YOU! PLEASE DON’T LET THESE WRETCHED 16+ PROPOSALS DESTROY YOUR BASIC O AND A PATTERN. CERTAINLY THIS SORT OF CHANGE, IF IMPLEMENTED IMMEDIATELY, WOULD BRING CHAOS.

SINCERELY YOURS.

DIFFERENCE BETWEEN CRYPTOGRAPHY AND STEGANOGRAPHY

THE METHODS OF STEGANOGRAPHY CONCEAL THE EXISTENCE OF THE MESSAGE, WHEREAS THE METHODS OF CRYPTOGRAPHY RENDER THE MESSAGE UNINTELLIGIBLE TO OUTSIDERS BY VARIOUS TRANSFORMATIONS OF TEXT.

Secret Communication

TechniquesConfidentiality Integrity Availability

Encryption Yes No Yes

Steganography Yes/No Yes/No Yes

Steganography CryptographyUnknown message passing Known message passing

Steganography prevents discovery of the very existence of communication

Encryption prevents an unauthorized party from discovering the contents of a communication

Little known Technology Common Technology

Technology still being developed for certain formats Most of algorithm known by all

Once Detected Message is known. Strong current algorithm are resistant to attacks, larger expensive computer power is required for cracking

Steganography does not alter the structure of the secret message

Cryptography alters the entire structure of the secret message

PHYSICAL TECHNIQUES

• CHARACTER MARKING: SELECTED LETTERS OF PRINTED OR TYPEWRITTEN TEXT ARE OVER WRITTEN IN PENCIL.

• INVISIBLE INK: A NUMBER OF SUBSTANCES CAN BE USED FOR WRITING BUT LEAVE NO VISIBLE TRACE UNTIL HEAT OR SOME CHEMICALIS APPLIED TO THE PAPER.

• PIN PUNCTURES: SMALL PIN PUNCTURES ON SELECTED LETTERS ARE ORDINARILY NOT VISIBLE UNLESS THE PAPER IS HELD UP IN FRONT OF A LIGHT.

DIGITAL TECHNIQUES

• CONCEALING MESSAGES WITHIN THE LOWEST BITS OF NOISY IMAGES OR SOUND FILES.• MODIFYING THE ECHO OF A SOUND FILE.• INCLUDING DATA IN THE IGNORED SECTIONS OF A FILE, SUCH AS AFTER THE

LOGICAL END OF THE CARRIER FILE.

STEGANOGRAPHY TERMS

• CARRIER OR COVER FILE: ORIGINAL MESSAGE OR A FILE IN WHICH HIDDEN INFORMATION WILL BE STORED.

• STEGO-MEDIUM: THE MEDIUM IN WHICH INFORMATION IS HIDDEN.

• PAYLOAD: THE INFORMATION WHICH IS TO BE HIDDEN OR CONCEALED.

• STEGANALYSIS: THE PROCESS OF DETECTING HIDDEN INFORMATION INSIDE A FILE.

BASIC STEGANOGRAPHY MODEL

Stegosystem Encoder

Stegosystem Decoder

Secret Message

Cover

CommunicationChannel

Stego Object

Estimate ofSecret

Message

OriginalCover

TYPES OF STEGANOGRAPHY

•TEXT STEGANOGRAPHY•IMAGE STEGANOGRAPHY•AUDIO STEGANOGRAPHY•VIDEO STEGANOGRAPHY

TEXT STEGANOGRAPHY

• TEXT STEGANOGRAPHY CAN BE APPLIED IN DIGITAL MAKEUP FORMAT SUCH AS PDF, DIGITAL WATERMARK OR INFORMATION HIDING.• IT IS MORE DIFFICULT TO REALIZE THE INFORMATION HIDING BASED ON TEXT.

THE SIMPLEST METHOD OF INFORMATION HIDING IS TO SELECT THE COVER FIRST, ADOPT GIVEN RULES TO ADD THE PHRASEOLOGICAL OR SPELLING MISTAKES, OR REPLACE WITH SYNONYM WORDS.

• LINE-SHIFT CODING: TEXT LINES ARE VERTICALLY SHIFTED TO ENCODE THE DOCUMENT UNIQUELY.

• WORD-SHIFT CODING: THE CODEWORDS ARE CODED INTO A DOCUMENT BY SHIFTING THE HORIZONTAL LOCATIONS OF WORDS WITHIN TEXT LINES, WHILE MAINTAINING A NATURAL SPACING APPEARANCE.

• FEATURE CODING: CERTAIN TEXT FEATURES ARE ALTERED, NOT ALTERED, DEPENDING ON THE CODEWORD.

IMAGE, AUDIO & VIDEO

• IMAGE, AUDIO & VIDEO STEGANOGRAPHY TAKES ADVANTAGE OF THE LIMITED CAPABILITIES OF THE HUMAN VISUAL & AUDITORY SYSTEM.• IN THIS TYPE THE LEAST SIGNIFICANT BITS (LSB) IS ALTERED WHICH DOES

NOT GREATLY AFFECT THE ORIGINAL QUALITY OF THE FILE.• THESE LSB CONTAIN THE SECRET MESSAGE.

APPLICATIONS

• CONFIDENTIAL COMMUNICATION AND SECRET DATA STORING.• PROTECTION OF DATA ALTERATION.• ACCESS CONTROL SYSTEM FOR DIGITAL CONTENT DISTRIBUTION.• MEDIA DATABASE SYSTEMS.

ADVANTAGES & DISADVANTAGES

ADVANTAGES:-• DIFFICULT TO DETECT• IT CAN BE DONE FASTER WITH LARGE NUMBER OF SOFTWARES• PROVIDES BETTER SECURITY FOR SHARING DATA IN LAN, MAN & WAN.DISADVANTAGES:-• IT REQUIRES A LOTOF OVERHEAD TO HIDE A RELATIVELY FEW BITS OF INFORMATION.• ONCE THE SYSTEM IS DISCOVERED IT BECOMES WORTHLESS.

COMBINED CRYPTO-STEGANOGRAPHY

Plain Text Encryption Cipher Text

Cipher Text

Stegosystem

Encoder

DecryptionPlain Text

Cover File

Stegosystem

DecoderCover File

Stego File

FUTURE SCOPE• STEGANOGRAPHY, THOUGH IT IS A FAIRLY NEW IDEA, THERE ARE CONSTANT

ADVANCEMENTS IN THE COMPUTER FIELD SUGGESTING ADVANCEMENTS IN THE FIELD OF STEGANOGRAPHY AS WELL. STEGANOGRAPHY IS LIKE DETECTING MICROSCOPIC NEEDLE IN A HAYSTACK.• WHAT IS SCARY IS THAT SUCH A SMALL TEXT FILE OF ONLY ONE OR TWO

SENTENCES MAYBE ALL THAT IS NEEDED TO COMMENCE A TERRORIST ATTACK. IN THE FUTURE, IT IS HOPED THAT THE TECHNIQUE OF STEGANALYSIS WILL ADVANCE SUCH THAT IT WILL BECOME MUCH EASIER TO DETECT EVEN SMALL MESSAGES WITHIN AN IMAGE.

CONCLUSION

THE INTENT OF THIS PRESENTATION WAS TO COVER SOME OF THE MORE COMMON METHODS OF DATA HIDING USING WIDESPREAD FILE FORMATS AND EASILY AVAILABLE TOOLS AS AN INTRODUCTION TO THE PRIMARY CONCEPTS OF STEGANOGRAPHY.

THANK YOU!