Week 1

Phone Phreaking 

Phreaking is a way (art) of hacking the telephone network. It began its history at the turn of the late 1960s and early 1970s. The thing is that in that times telephones used special sound signals of certain frequencies in their systems for managing calls. For instance, one particular beep could switch the line.

Firstly it was discovered by John Draper, who drew attention the gift whistle, which was placed in cookies packages. He saw that this whistle produces sound the same tone as the sound telephone company used to switch lines. The practical usage was in free calls, all you had to do was whistle into the phone so that the system takes this as an operator code. Afterwards, it got more usage, and you could make a telephone conference with more that 2 subscribers at the same time, listen to someone else's number, make call redirection or create/delete subscriber number.

Gift whistle

To do this task easier phone phreakers created devices called boxes (Eg. Blue box, black box). They represented a homemade device that generates beeps for various purposes.

Blue Box

DeCSS and banned number

DeCSS is the open-source program that could unlock and copy movies from commercial DVD-discs. It was developed by 3 people in 1999, but who is known is Jon Johansen. What is interesting is that not only the program became illegal (obviously) but also distribution of its code in any way. According to the laws of those times, you could've been jailed not for actual copying movies, but for possessing it on your pc or sending it. Funny fact that later people started to sell t-shirts with the source code of DeCSS, by the way profits went to lawsuits.

DeCSS drip

Later on mathematician Phil Carmory managed to encode the source code into a prime number. And this prime is registered in the archive as the first illegal prime to be discovered.

Click for larger image

The other way to distribute the source code was DeCSS haiku with detailed description of work algorithm.

Finally, I'd like to add that all this situation was mainly not about making piracy legal but about ridiculous banning sets of characters, images, etc. 

How to hide something in a picture

The thing I'm going tell you about is called steganography. Unlike encryption, where it is exactly clear that a message has arrived and it is hidden, with steganography, no one even knows about the existence of a message inside a file like an image.

So how is the coding process going?

In fact I'm speaking about LSB method with StegHide, which is quite easy, and it's better to use something more complicated for your goals.

An image retains binary information about each pixel color in RGB format. Any RGB color content is in range from 0 to 255. For instance red color in binary would be (255, 0, 0). Red = 255, green = 0, blue = 0;

The thing is that if we alter value from 255 to 253 (was 1111 1111, became 1111 1101) the picture will be indistinguishable from the original. And we can take these 2 bits to write any information. Thats it.