Use of Steganography & comparison between Cryptography and Steganography

2. 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

3. 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.

4. TYPES OF NETWORK SECURITY
•CRYPTOGRAPHY
•STEGANOGRAPHY

5. 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 UNLESSSOMEONE HAS A PROPER
KEY TO DECODE IT.

6. 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 THATNO ONE APART FROM THE
INTENDED RECIPIENT EVEN KNOWS THAT A MESSAGE HAS BEEN SENT.
• THIS CAN BE ACHIEVED BY CONCEALING THE EXISTENCE OF INFORMATIONWITHIN SEEMINGLY
HARMLESS CARRIERS OR COVERS.

7. EXAMPLE
SINCE EVERYONE CAN READ, ENCODING TEXT
IN NEUTRAL SENTENCESS IS DOUBTFULLY EFFECTIVE
SINCE EVERYONE CAN READ, ENCODING TEXT
IN NEUTRAL SENTENCES IS DOUBTFULLY EFFECTIVE

8. 3RD MARCH
DEAR 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.

9. 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
Techniques
Confidentiality Integrity Availability
Encryption Yes No Yes
Steganography Yes/No Yes/No Yes

10. Steganography Cryptography
Unknown 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

11. 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.

12. 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 AFTERTHE LOGICAL END OF THE CARRIER
FILE.

13. 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.

14. BASIC STEGANOGRAPHY MODEL
Stegosystem
Encoder
Stegosystem
Decoder
Secret
Message
Cover
Communication
Channel
Stego Object
Estimate of
Secret
Message
Original
Cover

15. TYPES OF STEGANOGRAPHY
•TEXT STEGANOGRAPHY
•IMAGE STEGANOGRAPHY
•AUDIO STEGANOGRAPHY
•VIDEO STEGANOGRAPHY

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

17. • 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.

18. 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.

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

21. 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.

22. COMBINED CRYPTO-
STEGANOGRAPHY
Plain Text Encryption Cipher Text
Cipher Text
Stegosystem
Encoder
DecryptionPlain Text
Cover File
Stegosystem
Decoder
Cover File
Stego File

23. 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 TWOSENTENCES 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.

24. 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.

25. THANK YOU!