Hidden Voices

Posted on June 1, 2008

Steganography is the process of hiding messages by embedding them in ordinary communications. It’s been practiced in history in a number of ways.

It is different from cryptography in which you can see the message but can’t tell what it means. With digital medium, images in particular, it is possible to hide a message in the code of the image. Since it is all binary, just zeros and ones, a portion can be changed to something else without appreciably changing the image.

So, a portion of the code could be used for messaging and it would take careful side-by-side comparisons of the image with the original to be able to see the difference. The advantage of steganography over cryptography is that messages do not attract attention to themselves, to messengers, or to recipients.

And now, two Polish information scientists say they are developing a steganographic system for VoIP networks. If you use a service like Vonage, since it’s digital just like that JPEG image, the same thing can be accomplished. All you would notice as you talked on the phone might be something like ‘Vonage isn’t as clear today’ or ‘there seems to be a little problem with the connection’.

Purpose of all this? Don’t really know, but if there are tools out there, nefarious uses will certainly follow. There may be terrorists right now, saying ah-ha!