Steganography
What is Steganography?
Steganography
is the art and science of hiding information by embedding messages
within other, seemingly harmless images or other types of media.
The
word steganography is of Greek origin and means "concealed writing".
The first recorded use of the term was in 1499 by Johannes Trithemius in
his Steganographia, a treatise on cryptography and steganography
disguised as a book on magic. Generally, messages will appear to be
something else: images, articles, shopping lists, or some other
covertext and, classically, the hidden message may be in invisible ink
between the visible lines of a private letter.
It
originated with the Greeks, and it means “covered writing”. It can be
traced back for centuries, when messengers used to shave their heads,
tattoo the message to their head, then wait until their hair grew back,
travel to their destination, and finally shave their head again to
reveal the message. Another technique that was used was etching a
message in a wooden tablet, and then covering it with was. They also
used invisible ink, null ciphers, and microdots to convey messages.
Steganography has come a long way since those days. Now, steganography
is the altering of bits in either an image, sound document, or even
another document, to hide a message.
Steganography
has become increasingly popular in the past years, due to the explosion
of the internet and multi-media use in general. Most of the attention
has been drawn now because of the malicious use of the technique. It has
been used for terrorism, fraud, espionage, etc. It has become a threat
not only to individuals and businesses, but to government agencies and
homeland security, not just in the United States, but all across the
world. This is why there is now a growing interest in steganalysis,
which is the detection of embedded data. The problem is, there are so
many methods to embed the information, it is hard to develop programs to
distinguish between the different types. There are over 100 free
steganography programs, such as Outguess, available on the internet, and
it is reported that there have been over 1 million downloads of this
software, which goes to show how popular steganography is becoming. It
is not always used in a malevolent manner, some people just like to keep
their private information secret, or use it as another way to encrypt
important information, but the fact is that it can be used in a criminal
way, and that is what the concern is about.
What are some steganography programs?
Not only are there several programs that hide information, there are
several different methods for doing so. There are three basic ways:
injection, substitution, and generation. With injection, the idea is to
find areas in the file that are not being used, like at the end of a
song for example, and insert the data in that space. Substitution finds
the least significant bits, and places the hidden document there.
Generation creates an entirely new file, based around the information
that you want hidden, for example, creating an image of a painting based
on the bits that are in the file.
There are also
several different programs, with their own methods that all fall under
one of the above mentioned categories. Outguess is one such program, it
is a universal steganographic tool that allows the insertion of hidden
information into the redundant bits of data sources. It determines the
maximum amount of information that can be inserted into a jpeg without
changing the statistical counts, making it difficult to find using
statistical tests. There are also several others such as S-tools.
What is Steganalysis?
Steganalysis is simply the detection of steganography by a third party.
This is a relatively new field, since the new technology behind
steganography is just becoming popular. There are two main types of
steganalysis: visual analysis and statistical (algorithmic) analysis.
Visual analysis tries
to reveal the presence of hidden information through inspection with
the naked eye or with the assistance of a computer, which can separate
the image into bit planes for further analysis.
Statistical analysis is
more powerful and successful, because it reveals the smallest
alterations in an image’s statistical behavior. There are several
statistical tests which can be run on an image: average bytes,
variations of the bytes, skew, kurtosis, average deviation and
differential values.
Technical Steganography
Technical
steganography offers a broad variety of methods. It is nearly
impossible to divide up all these methods. & Its uses scientific
methods to hide a message, such as the use of invisible ink or microdots
and other size-reduction methods.
Some methods of technical steganography are:
Invisible Ink
One of the methods with the longest tradition.
Microdots
A method that can be used to hide up to one page in a dot.
Computer-based Methods
Uses redundant information in texts, pictures, sounds, videos, ...
Linguistic Steganography
Linguistic
steganography hides the message in the carrier in some nonobvious ways
and is further categorized as semagrams or open codes.
Open Codes
The
openly readable text is in the case of open codes mostly well
constructed. It can contain certain words or sentences, certain letters
can be on certain places in the text or words can be hidden in vertical
or reversed position.
The main methods are:
Masking
In
a text there could be sentences or words starting with certain letters,
which have another meaning. There can also be metaphors, etc. In so far
all kinds of jargons are in fact masking.
Cues
A certain word
appearing in the text transports the message. This message is very
often used in wartime to broadcast information to resistance groups in
the enemy's country.
Null-ciphers
The hidden text could be
reconstructed by taking the first (second,...) letter of each word (or
after the punctuation mark, etc.).
Hidden messages could also be
found vertically, diagonally or in reversed order. It could also be
necessary to re-write the open text in other form (e.g. with a certain
number of letters per line).
# Semagrams hide information by
the use of symbols or signs. A visual semagram uses innocent-looking or
everyday physical objects to convey a message, such as doodles or the
positioning of items on a desk or Website. A text semagram hides a
message by modifying the appearance of the carrier text, such as subtle
changes in font size or type, adding extra spaces, or different
flourishes in letters or handwritten text.
As an increasing
amount of data is stored on computers and transmitted over networks, it
is not surprising that steganography has entered the digital age. On
computers and networks, steganography applications allow for someone to
hide any type of binary file in any other binary file, although image
and audio files are today's most common carriers.
Steganography
provides some very useful and commercially important functions in the
digital world, most notably digital watermarking. In this application,
an author can embed a hidden message in a file so that ownership of
intellectual property can later be asserted and/or to ensure the
integrity of the content. An artist, for example, could post original
artwork on a Website. If someone else steals the file and claims the
work as his or her own, the artist can later prove ownership because
only he/she can recover the watermark . Although conceptually similar to
steganography, digital watermarking usually has different technical
goals. Generally only a small amount of repetitive information is
inserted into the carrier, it is not necessary to hide the watermarking
information, and it is useful for the watermark to be able to be removed
while maintaining the integrity of the carrier.
>>Steganography Tools:-
Softwares:
1. S Tools
S-Tools hides in a variety of cover media. This software is a good
illustration of different versions hiding in different media. These
versions cover hiding in BMP, GIF, WAV, and even on unused floppy disk
space.
2.MP3Stego.
which hides text files within larger text files, and lastly a tool that hides files in MP3s called MP3 Stego
3.Steganos Suite
Tested one commercial steganography product, Steganos Suite.
4.Camouflage 2.0
5.Dmagic.
Hides files and folders on Windows systems
6.Hermetic Stego
by Peter Meyer, Hermetic Systems This program is capable of hiding in a BMP image or across multiple BMP images.
7.jpeg-jsteg
DOS hides information in the DCT coefficients of JPEG's JFIF image format.
8.Snow
Snow (also variants include !SnowDOS, SnowJava, JSnow
By Matthew Kwan is available in both DOS and JAVA executable formats.
"snow exploits the steganographic nature of whitespace. Locating
trailing whitespace in text is like finding a polar bear in a
snowstorm. And it uses the ICE encryption algorithm, so the name is
thematically consistent.
9.Steghide
Source code is aviailable and several ports are available for different
operating systems. IMAGES: (BMP) AUDIO: (WAV, AU )
10.wbStego
wbStego is a steganography to hide data in bitmaps, text files and HTML files.
practical view
Hide File In Image
HOw Can We Hide The File In Image.
1. Gather the file you wish to bind, and the image file, and place them in a folder. I will be using C:\New Folder
-The image will hereby be referred to in all examples as xyz.jpg
-The file will hereby be referred to in all examples as New Text Document.txt
2.
Add the file/files you will be injecting into the image into a WinRar
.rar or .zip. From here on this will be referred to as (secret.rar)
3. Open command prompt by going to Start > Run > cmd
4. In Command Prompt, navigate to the folder where your two files are by typing
cd location [ex: cd C:\New Folder]
5. Type [copy /b xyz.jpg + secret.rar xyz.jpg] (remove the brackets)
Congrats,
as far as anyone viewing is concerned, this file looks like a JPEG,
acts like a JPEG, and is a JPEG, yet it now contains your file.
In order to view/extract your file, there are two options that you can take
a) Change the file extension from xyz.jpg to xyz.rar, then open and your file is there
b) Leave the file extension as is, right click, open with WinRar and your file is there
EnJoy HacKinG...
