IS THERE A SECRET BEHIND MONA LISA's SMILE ???

The curiosity of Mona Lisa's smile became more when I read Dan Brown's The DaVinci Code!!! This book made me go back to one topic which i had prepared some time back - Steganography........

What's Steganography.....and this only makes me more curious to know if there is any thing as real as in the fiction by the thriller writer Dan Brown.....The book, picked up on a random is one best seller and certainly leaves one trying to think if there can be anything as interesting ......as knowing the secrets behind the masterpieces ........such ......as ...Mona Lisa........

Fiction - A myth or reality........... (maybe I can make this as one of my blogs........ :) )

Let me get back to what Steganography is..... :)

The most simplest way of using Steganography is to use lemon juice to write text on paper, let the paper dry and the words written would reappear on the apparently blank sheet of paper if one heated it.

Another common example to see for steganography in our daily lives is the noticing of the image or watermark on notes when held upto light.
Both these types of situations are examples of steganography, the art of secret writing.

Steganography, from the Greek, means covered, or secret writing, and is a long-practiced form of hiding information. Although related to cryptography, they are not the same. Steganography's intent is to hide the existence of the message, while cryptography scrambles a message so that it cannot be understood.

More precisely: "The goal of steganography is to hide messages inside other harmless messages in a way that does not allow any enemy to even detect that there is a second secret message present.''

Steganography includes a vast array of techniques for hiding messages in a variety of media. Among these methods are invisible inks, microdots, digital signatures, covert channels and spread-spectrum communications. Today, thanks to modern technology, steganography is used on text, images, sound, signals, and more.

The advantage of steganography is that it can be used to secretly transmit messages without the fact of the transmission being discovered. Often, using encryption might identify the sender or receiver as somebody with something to hide. For example, that picture of your cat could conceal the plans for your company's latest technical innovation.

However, steganography has a number of disadvantages as well. Unlike encryption, it generally requires a lot of overhead to hide a relatively few bits of information. However, there are ways around this.

Also, once a steganographic system is discovered, it is rendered useless. This problem, too, can be overcome if the hidden data depends on some sort of key for its insertion and extraction.In fact, it is common practice to encrypt the hidden message before placing it in the cover message.

However, it should be noted that the hidden message does not need to be encrypted to qualify as steganography. The message itself can be in plain English and still be a hidden message. However, most steganographers like the extra layer of protection that encryption provides. If your hidden message is found, then at least make it as protected as possible.

Going a little back to history ........... :) just to show from how back these techniques are being used.........after all most of our present technologies to date have some relation from history ..........

World War II marked a period of intensive steganographical experimentation. Early in the war, steganographic technology consisted almost entirely of invisible inks.

Later, null ciphers (unencrypted messages) were used to hide secret messages. The null cipher, which often appeared to be an innocent message about ordinary occurrences, would not alert suspicion, and would thus not be intercepted.

For example, a German spy sent the following message during WWII:

Apparently neutral's protest is thoroughly discounted and ignored. Isman hard hit. Blockade issue affects pretext for embargo on byproducts, ejecting suets and vegetable oils.

Decoding this message by taking the second letter in each word reveals the following secret message:

Pershing sails from NY June 1.

In this article, an introductory look at steganography is taken. Most data-hiding systems take advantage of human perceptual weaknesses, but have weaknesses of their own.

One can conclude that for now, it seems that no system of data-hiding is totally immune to attack. However, steganography has its place in security.

It in no way can replace cryptography, but is intended to supplement it. Its application in watermarking and fingerprinting, for use in detection of unauthorised, illegally copied material, is continually being realised and developed. Also, in places where standard cryptography and encryption is outlawed, steganography can be used for covert data transmission.

Steganography, formerly just an interest of the military, is now gaining popularity among the masses. Soon, any computer user will be able to put his own watermark on his artistic creations.
Steganography has its place in security. It is not intended to replace cryptography but supplement it.

Hiding a message with steganography methods reduces the chance of a message being detected. However, if that message is also encrypted, if discovered, it must also be cracked (yet another layer of protection).

There are an infinite number of steganography applications. It goes well beyond simply embedding text in an image. Steganography does not only pertain to digital images but also to other media (files such as voice, other text and binaries; other media such as communication channels, the list can go on and on).

Consider the following example:

A person has a cassette tape of Pink Floyd's "The Wall."

The plans of a Top Secret project (e.g., device, aircraft, covert operation) are embedded, using some steganographic method, on that tape.

Since the alterations of the "expected contents" cannot be detected, (especially by human ears and probably not easily so by digital means) these plans can cross borders and trade hands undetected.

How do you detect which recording has the message? This is a trivial (and incomplete) example, but it goes far beyond simple image encoding in an image with homogeneous regions. Part of secrecy is selecting the proper mechanisms.

In and of itself, steganography is not a good solution to secrecy, but neither is simple substitution and short block permutation for encryption. But if these methods are combined, you have much stronger encryption routines (methods).

For example (again over simplified): If a message is encrypted using substitution (substituting one alphabet with another), permute the message (shuffle the text) and apply a substitution again, then the encrypted ciphertext is more secure than using only substitution or only permutation. NOW, if the ciphertext is embedded in an image, video, voice, etc., it is even more secure.

If an encrypted message is intercepted, the interceptor knows the text is an encrypted message.

With steganography, the interceptor may not know the object contains a message.

With technology reaching new heights everyday, one has to think of innovative methods and schemes to make their creations ......secure.....................New technology proportional to new security methods......................!!!!!!!!!!