This document discusses different digital security techniques including cryptography, steganography, and watermarking. Cryptography involves encrypting messages to hide their meaning and can provide confidentiality, integrity, and authentication. Steganography embeds hidden messages within ordinary files like images or audio so the very existence of the message is concealed. Watermarking similarly embeds invisible signatures or markings within files but is intended to identify ownership rather than conceal messages. Both steganography and watermarking can apply techniques like modifying least significant bits of image pixel data.

2. Evolution
Cryptography
Watermarking
Steganography

3. Cryptography
Cryptography derived its name from a Greek
word called “Kryptos” which means “Hidden
Secrets”.
Cryptography is the practice and study of hiding
information. It is the Art or Science of
converting a plain text into a data which can’t
be understood and again retransforming that
message into its original form.
It provides Confidentiality, Integrity, Accuracy.

4. Symmetric Cryptography
Asymmetric Cryptography

5. Steganography
Greek Words :
STEGANOS – “Covered”
GRAPHIA – “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.
Stegosaurus: a covered lizard

6. Types of Steganography
Text
audio
image
video
protocol

7. Image steganography algorithm
LSB - Example
A sample raster data for 3 pixels (9 bytes)
may be:
Inserting
the binary
value for
A
(10000001)
changes
4 bits
00100111 11101001 11001000
00100111 11001000 11101001
11001000 00100111 11101011
00100111 11101000 11001000
00100110 11001000 11101000
11001001 00100111 11101011

8. LSB - Uses
 Storing passwords and/or other confidential
information
 Covert communication of sensitive data
 Speculated uses in terrorist activities
 Being widely used to hide and/or transfer
illegal content

10. Watermarking
A watermark is a recognizable image or
pattern in paper that appears as various
shades of lightness/darkness when viewed
by transmitted light (or when viewed by
reflected light, a top a dark
background), caused by thickness
variations in the paper.

11. Digital Watermarking
A digital watermark is a digital signal or
pattern inserted into a digital document such
as text, graphics or multimedia, and carries
information unique to the copyright owner,
the creator of the document or the authorized
consumer.
VISIBLE WATERMARKING
INVISIBLE WATERMARKING

13. EXAMPLE OF INVISIBLE WATERMARKING

14. EXAMPLE OF VISIBLE WATERMARKING
+ =

15. UV Watermarking

16. APPLICATION FIELD FOR WATERMARKING
INTERNET
TV
IIII
INTERNET
RADIO
E-Book
INTERNET
NEWSPAPER
EDUCATION
MATERIAL
INTERNET
MAGZINE
DOCUMENTS
CERTIFICATES
AUDIO
TEXT
IMAGE
VIDEO
GRAPHICS
WATERMARKING
TECHNOLOGY

17. Watermarking Vs. Steganography
Goal of Steganography
 Intruder Cannot detect message
 Primarily 1:1 communication
 Goal of Watermarking
 Intruder cannot remove or replace the
message
 Primarily 1: many communication

18. Cryptography vs. Steganography
Cryptography: although encypted and
unreadable, the existence of data is not
hidden
WHEREAS
Steganography: no knowledge of the
existence of the data

19. REFERENCES
 http://www.garykessler.net/library/steganography.html
 http://www.fbi.gov/about-us/lab/forensic-sciencecommunications/
fsc/july2004/research/2004_03_research01.htm
 http://stegano.net/tutorial/steg-history.html
 http://www.strangehorizons.com/2001/20011008/steganography.shtml

20. QUERIES ?

21. “For every lock there is a Key…
It is better to KEEP SAFE YOUR LOCK THAN THE KEY”