|
Today, in the Toronto Sunday Star newspaper, I encountered an article, part of a series leading up to the Sept. 11 2nd year anniversary of the attack on the World Trade Centre. Oddly enough, the article had nothing to do with politics, but with technology: the use of "steganography", a technology that allows coded messages to be embedded in web sites. Apparently it is this technology which is used by Al Qaeda to communicate to its members across the world, wherever there is an internet link. It is the same techology used by proponents of democracy to send coded messages into countries that are strictly regulated and controlled, such as China.
Obviously, the tool is not the problem, the tool's operators are. The article displayed a picture of a colourful flower with the caption, "More than meets the eye". The picture had two hidden messages: hidden image and encoded text. Most web images are made up of a palette of 256 colours. By reducng the palette to 32 basic colours, hidden images are exposed. As for text messages, they are encoded in the least significant bit of each 8-bit colour pixel. The letter A which is 10000011 binary, will have each of its 8 bits saved as in the encoded pixels. The "steganography" software performs the encoding/decoding.
Things sure have changed since the days of my youth when the best secrets were written in "lemon juice" and could only be read after you heated the paper with a lightbulb and could then read the imprinted text.
|
