7/29/2019 Steganography 111107140802 Phpapp02
1/39
Page 1Page 1
By
Harsh Madhani
Computer Engineering
Steganography
7/29/2019 Steganography 111107140802 Phpapp02
2/39
Page 2
cryptography
hidden
writing
A secret manner of writing, Generally, the art ofwriting or solving ciphers.
Oxford English Dictionary
7/29/2019 Steganography 111107140802 Phpapp02
3/39
Page 3
cryptology
hidden
speaking
1967 D. Kahn, Codebreakers p. xvi, Cryptology is the
science that embraces cryptography and cryptanalysis,but the term cryptology sometimes loosely designatesthe entire dual field of both rendering signals secureand extracting information from them.
Oxford English Dictionary
7/29/2019 Steganography 111107140802 Phpapp02
4/39
Page 4
Steganography
covered
writing
The art of secret (hidden) writing
7/29/2019 Steganography 111107140802 Phpapp02
5/39
Page 5Page 5
PATSAHORNYEGGSTEGANOGRAPHY
7/29/2019 Steganography 111107140802 Phpapp02
6/39
Page 6
Steganography
Art and science of communicating in a way thathides the existence of a message
signal or pattern imposed on content
persistent under transmission not encryption
original image/file is intact
not fingerprinting
fingerprinting leaves separate file describing contents
7/29/2019 Steganography 111107140802 Phpapp02
7/39Page 7
Steganography includes the concealment ofinformation within computer files.
In digital Steganography, electroniccommunications may include steganographiccoding inside of a transport layer, such as adocument file, image file, program or protocol.
Media files are ideal for steganographictransmission because of their large size.
As a simple example, a sender might startwith an innocuous image file and adjust thecolor of every 100th pixel to correspond to aletter in the alphabet, a change so subtle thatsomeone not specifically looking for it isunlikely to notice it.
http://en.wikipedia.org/wiki/Pixelhttp://en.wikipedia.org/wiki/Pixel7/29/2019 Steganography 111107140802 Phpapp02
8/39Page 8
Classic techniques
Invisible ink (1st century AD - WW II)
Tatoo message on head
Overwrite select characters in printed type inpencil look for the gloss
Pin punctures in type
Microdots (WW II)
Newspaper clippings, knitting instructions,XOXO signatures, report cards,
i i
7/29/2019 Steganography 111107140802 Phpapp02
9/39Page 9
igita teganograp y
Modern Steganography entered the world in1985 with the advent of the personalcomputer being applied to classicalSteganography problems.
Over 925 digital Steganography applicationshave been identified by the SteganographyAnalysis and Research Center.DigitalSteganography techniques include:
Concealing messages within the lowest bits ofnoisy images or sound files.
Chaffing and winnowing.
http://en.wikipedia.org/wiki/Steganography_toolshttp://en.wikipedia.org/wiki/Image_noisehttp://en.wikipedia.org/wiki/Chaffing_and_winnowinghttp://en.wikipedia.org/wiki/Chaffing_and_winnowinghttp://en.wikipedia.org/wiki/Image_noisehttp://en.wikipedia.org/wiki/Steganography_tools7/29/2019 Steganography 111107140802 Phpapp02
10/39Page 10
Concealed messages in tampered executablefiles, exploiting redundancy in the targetedinstruction set.
Pictures embedded in video material(optionally played at slower or faster speed).
Injecting imperceptible delays to packets
sent over the network from the keyboard. Delays in keypresses in some applications (
telnet or remote desktop software) can mean
a delay in packets, and the delays in thepackets can be used to encode data.
Imagebit-plane complexity segmentation Steganograph
http://en.wikipedia.org/wiki/Instruction_sethttp://en.wikipedia.org/wiki/Telnethttp://en.wikipedia.org/wiki/Remote_desktop_softwarehttp://en.wikipedia.org/wiki/BPCS-Steganographyhttp://en.wikipedia.org/wiki/BPCS-Steganographyhttp://en.wikipedia.org/wiki/Remote_desktop_softwarehttp://en.wikipedia.org/wiki/Telnethttp://en.wikipedia.org/wiki/Instruction_set7/29/2019 Steganography 111107140802 Phpapp02
11/39Page 11
Chaffing & Winnowing
Separate good messages from the bad ones
Stream of unencoded messages with signatures Some signatures are bogus
Need key to test
M0M3 M1M2 M0M3 M1M2
Alice Bob
M0M3 M1M2
Irene
? ? ? ?
OK
7/29/2019 Steganography 111107140802 Phpapp02
12/39Page 12
Null Cipher
Hide message among irrelevant data
Confuse the cryptoanalyst
7/29/2019 Steganography 111107140802 Phpapp02
13/39
Page 13
Null Cipher
Hide message among irrelevant data
Confuse the cryptoanalyst
Big rumble in New Guinea.
The war oncelebrity acts should end soon.Over fourbig ecstatic elephants replicated.
7/29/2019 Steganography 111107140802 Phpapp02
14/39
Page 14
Null Cipher
Hide message among irrelevant data
Confuse the cryptoanalyst
Big rumble in New Guinea.
The war oncelebrity acts should end soon.Over fourbig ecstatic elephants replicated.
Bring two cases of beer.
t t
7/29/2019 Steganography 111107140802 Phpapp02
15/39
Page 15
etwor teganograp y
Network Steganography utilizes
communication protocols' control elementsand their basic intrinsic functionality.
Typical network Steganography methods
involve modification of the properties of asingle network protocol.
Moreover, it is feasible to utilize the relationbetween two or more different network
protocols to enable secret communication.These applications fall under the term inter-protocol Steganography.[14]
http://en.wikipedia.org/wiki/Steganographyhttp://en.wikipedia.org/wiki/Steganography7/29/2019 Steganography 111107140802 Phpapp02
16/39
Page 16
Steganophony - the concealment of messages
in Voice-over-IP conversations, e.g. theemployment of delayed or corrupted packetsthat would normally be ignored by the
receiver (this method is called LACK - LostAudio Packets Steganography), or,alternatively, hiding information in unusedheader fields.
http://en.wikipedia.org/wiki/Voice-over-IPhttp://en.wikipedia.org/wiki/Voice-over-IP7/29/2019 Steganography 111107140802 Phpapp02
17/39
Page 17
Image watermarking
Spatial domain watermarking
bit flipping color separation
Frequency domain watermarking embed signal in select frequency bands (e.g. high
frequency areas) apply FFT/DCT transform first
e.g. Digimarc
watermark should alter the least perceptible bits these are the same bits targeted by lossy image
compression software
7/29/2019 Steganography 111107140802 Phpapp02
18/39
Page 18
UV Watermarking
7/29/2019 Steganography 111107140802 Phpapp02
19/39
Page 19
Machine ID codes in laser printers
See http://www.eff.org/Privacy/printers/
7/29/2019 Steganography 111107140802 Phpapp02
20/39
Page 20
Machine ID codes in laser printers
7/29/2019 Steganography 111107140802 Phpapp02
21/39
Page 21
Machine ID codes in laser printers
7/29/2019 Steganography 111107140802 Phpapp02
22/39
Page 22
Machine ID codes in laser printers
7/29/2019 Steganography 111107140802 Phpapp02
23/39
7/29/2019 Steganography 111107140802 Phpapp02
24/39
Page 24
Text
Text lines shifted up/down (40 lines text
240 codes) word space coding
character encoding - minor changes to shapes
of characters
7/29/2019 Steganography 111107140802 Phpapp02
25/39
Page 25
Image Steganography
Image of a tree with asteganographically hiddenimage. The hidden image isrevealed by removing all butthe two least significant bits
of each color component and asubsequent normalization.
Image of a cat extractedfrom the tree imagebesides.
http://en.wikipedia.org/wiki/Bithttp://en.wikipedia.org/wiki/Color_componenthttp://en.wikipedia.org/wiki/Normalization_(image_processing)http://en.wikipedia.org/wiki/Normalization_(image_processing)http://en.wikipedia.org/wiki/Color_componenthttp://en.wikipedia.org/wiki/Bit7/29/2019 Steganography 111107140802 Phpapp02
26/39
Page 26
Audio
Perceptual coding
inject signal into areas that will not be detected by humans may be obliterated by compression
Hardware with copy-protection
not true watermarking - metadata present on media DAT
minidisc
presence of copy protection mechanisms often failed to give
the media wide-spread acceptance
7/29/2019 Steganography 111107140802 Phpapp02
27/39
Page 27
Video
Coding still frames - spatial or frequency
data encoded during refresh closed captioning
visible watermarking used by most networks (logo at bottom-right)
D t E b ddi S it S h
7/29/2019 Steganography 111107140802 Phpapp02
28/39
Page 28
Data Embedding Security Schemes
One of the areas that improves
steganographic robustness is usage of a keyscheme for embedding messages.Key schemeterm means a procedure of how to use keysteganographic system based on the extentof its use. However, when the steganographicrobustness is increased a bandwidth of thewhole embedding system is decreased.
Therefore the task of a scheme selection forachieving the optimal values of thesteganographic system is not trivial.
7/29/2019 Steganography 111107140802 Phpapp02
29/39
Page 29
The first level of protection is determined only by the choice ofembedding algorithm. This may be the least significant bits
modification algorithm, or algorithms for modifying the frequency orspatial-temporal characteristics of the container. The first level ofprotection is presented in any steganographic channel.Steganographic system in this case can be represented as shown atThe First Protection Level Schemefigure.
7/29/2019 Steganography 111107140802 Phpapp02
30/39
Page 30
The second protection level of the steganographic system, as well as all levels ofprotection of the higher orders, is characterized by the use of Key (password)via steganographic modification. An example of a simple key scheme, whichprovides a second level of protection, is to write the unmodified or modifiedpassword in the top or bottom of the message; or the distribution of thepassword sign on the entire length of the steganographic channel. Such keyschemes do not affect the distribution of messages through the container and donot use a message preprocessing according to the defined key (see figure TheSecond Protection Level Scheme). This kind of steganographic systems are usedin such tasks as, for instance, adding a digital signature for proof of copyright.Data embedding performance is not changed in comparison with the fastest
approach of the first protection level usage.
7/29/2019 Steganography 111107140802 Phpapp02
31/39
7/29/2019 Steganography 111107140802 Phpapp02
32/39
Page 32
The difference between the fourth protection level scheme and thethird one is that in steganographic system there are twodistribution functions of a message within a container are used. The
first is responsible for a message samples selection according tosome function G(Q, N), and the second function F(P, L)is responsiblefor position selection in a container for message sample hiding. HereQ the size of message block to be inserted; N the size (in bits)of one sample of the message file (see figure The Fourth Protection
Level Scheme).
C d d i
7/29/2019 Steganography 111107140802 Phpapp02
33/39
Page 33
Countermeasures and detection
In computing, detection of steganographically
encoded packages is called steganalysis. Thesimplest method to detect modified files,however, is to compare them to known
originals. For example, to detect information beingmoved through the graphics on a website, ananalyst can maintain known-clean copies of
these materials and compare them against thecurrent contents of the site. Thedifferences, assuming the carrier is the same,will compose the payload.
Ste anal sis can have a two-sided a roach
l h d d h
http://en.wikipedia.org/wiki/Steganalysishttp://en.wikipedia.org/wiki/Steganalysis7/29/2019 Steganography 111107140802 Phpapp02
34/39
Page 34
Steganalysis can have a two-sided approachthat involves detecting both artifacts andsignatures of known steganography
applications.All files on a suspect filesystemcan be hashed using a hash function and thencompared to a hash table of knownsteganography applications to show that a
particular steganography application is, orwas, present on the system at some point intime. The second step in the steganalysisprocess is to search all files on a suspect
filesystem for signatures (uniquelyidentifiable byte patterns) that act asidentifiers that are embedded as a result ofhiding the information.
http://en.wikipedia.org/wiki/Hash_functionhttp://en.wikipedia.org/wiki/Hash_tablehttp://en.wikipedia.org/wiki/Hash_tablehttp://en.wikipedia.org/wiki/Hash_function7/29/2019 Steganography 111107140802 Phpapp02
35/39
Page 35
Difference between Cryptography andSteganography & Watermarking
Cryptography hides the content of themessage, but not the existence of themessage; steganography & watermarking hide
both the contents and existence of themessage.
7/29/2019 Steganography 111107140802 Phpapp02
36/39
Page 36
Then what is the difference between
Steganography and Watermarking?
Steganography performs message hiding such
that an attacker cannot detect the presenceof the message in the image/video/audio;watermarking hides the message such that anattacker cannot tamper with the message
contained within the image/video/audio.
A li ti
7/29/2019 Steganography 111107140802 Phpapp02
37/39
Page 37
Applications
Used in modern printers
Allegedly used by terrorists. e.g. It is allegedthat Al-Queda used Chaffing to encryptmessages at time of 9/11 and exchanging imagesvia ebay.com.
Alleged use by intelligence services: In2010, the FBI revealed that the Russian foreignintelligence uses customized steganographysoftware for embedding encrypted textmessages inside image files for certaincommunications with "illegal agents stationedabroad.
Digital Watermarking
7/29/2019 Steganography 111107140802 Phpapp02
38/39
Page 38
setec astronomy
The Conclusion
The conclusion is that in this world there arestill
too many secrets
7/29/2019 Steganography 111107140802 Phpapp02
39/39
IT MEANS: THANK YOU
Hanky Out
Top Related