The Message Must Get Through
The year is 300A.D., and you're part of a war machine
unlike anything the world has ever seen. You are a field
General for the Roman Empire and charged with assimilating
yet another non-Roman culture. Your current mission; get
tactical information you've collected in the field to an
outpost one hundred miles away. The land between you and the
outpost is treacherous and filled with enemy. The
information you've collected is critical to the success of
the current campaign and must reach the remote outpost
intact. This will call for ingenious deception.
You send for a messenger, who is in reality a Roman slave.
The messenger's head is shaved clean, and the message for
the outpost is tattooed on his head. Several weeks later,
the messengers hair has grown in and completely concealed
the secret information. The messenger departs and one week
later reaches the outpost. A quick head shave and the
outpost has the information needed to ensure yet another
victory for Rome.
This is one of the earliest forms of Steganography on
record. The art of hiding messages within another medium
and avoiding detection.
The Ancient Technology Of Deception
A Modern Day Threat
Take a look at the following two images at
http://www.defendingthenet.com/stgpic.htm. The first picture
is quite normal. The second picture looks exactly like the
first. However, the second picture is not a normal picture
at all. It contains a portion of the article you are
currently reading in the form of a Microsoft Word document.
It has been embedded in the image using a Steganography
program and is nearly undetectable. Not only can you not
see a visual difference in the picture, the file size of the
original and the Stego Medium (image with the hidden text)
is exactly the same.
There are several programs on the Internet that may be able
to detect a small anomaly in the picture, like "stegdetect",
but the method used to embed the secret document is
protected by a key, or password, as well.
The technology behind effective Steganography is quite
complex and involves serious mathematical computations.
Computers and technology make this a trivial task and make
this art of deception a serious threat to the security of
information. Company's that regard their information
proprietary, and rely on the security and integrity of their
intellectual property, could be at significant risk.
A Real World Example Of Steganography
Many organizations protect their internal network resources
and information by using sophisticated security measures,
such as firewalls. Many firewalls can block e-mail
attachments such as executables, spreadsheets, and
documents, and do so by looking for file extensions. Some
security measures, or content filters, can actually
determine if the particular file or attachment is actually
the type to be blocked, a spreadsheet for instance, by
analyzing the contents of the file. This helps prevent the
transmission of file attachments that have had their
extensions altered or removed.
But how many organizations block the sending of image files
like, .jpg or .bmp images.
Imagine having someone on the inside of a company who
secures a proprietary document. This person then embeds the
document into a picture and sends it to an e-mail address on
the Internet. The company's defense systems block many
types of file attachments, but image files are not
considered a risk, so they are allowed through. The sender
and receiver previously agreed on the method and type of
deception. Using a Steganography package freely available
on the Internet the task was easily and securely executed.
The company was completely unaware of the fact that
important information was leaked.
There are so many components to this form of deception, I
could write ten pages on the subject alone. The purpose for
this article is to make people aware of this form of
deception and the threat it poses to digital security.
Steganography also has an impact on non-digital information
as well. And, pictures are not the only medium that can be
used. Sound files are another favorite host for embedding
If you would like to see Steganography in action you can
download "The Third Eye" from the following link
http://www.defendingthenet.com/downloads/steg.zip. It is a
freely distributable Steganography program and was used to
create the two image examples referenced above. This
download contains the two images above and you will be able
to open the image with the hidden text and extract it. The
zip file contains a README.TXT file that will give you full
instructions on how to extract the hidden text in the
But first, you will need the password! Can you guess it?
I'll give you a clue: What form of deception did the Roman
General use to send his message?**
*The story "The message must get through" although based on
documented information about a Roman General performing such
an act of deception, is fictional and was written as
illustration of such an event strictly for use in this
**You should be able to easily guess the password however I
must point out that the password should be entered all
About The Author
Darren Miller is an Information Security Consultant with
over sixteen years experience. He has written many technology
& security articles, some of which have been published in
nationally circulated magazines & periodicals. Darren is a
staff writer for http://www.defendingthenet.com and several other
e-zines. If you would like to contact Darren you can e-mail
him at firstname.lastname@example.org or
email@example.com. If you would like to know
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