hello friends,

actually i am out of work (holidays yeah) and i love copy protections and the way to defeat them and so on, its like a cat and mouse game.

so now i am interested in defeating the css protection from dvds. yes i know, ist a bad old protection, but it has some historical things and i have some old dvds which only have css.

so i used google and found some information and the world known decss code. So i also use c/c++ as dev. language but i am not a very hard programmer. so i want to ask if someone can explain me the code. Not the complete code, because many things are easy to understand but i think not the permuation tables called CSStab1-4, some are 512bit long and some are 256 bit long.

My question is, what are these tables stand for and how are they build ?
so i mean why should the devloper use these hex values and why and how he get them?


i hope someone can help me.

bye
disckiller
greetz from CH

14 readings since i poste, so does nobody can help me ?

Patience is a virtue.

lol, what do you mean ?
patience to wait for someone to help or to find it self ?

i have actually read some about "what is permutation" and now i know that it ist to change something against something else, and its often use as a matrix like an array.

but im still attached to how to get these tables ?

now, found over 10 different articels which describes the css algorithm but they always only say that the bytes will xored with a byte permutation table. nobody is talking about how to create this table ?

does nobody have an idea ?

if it is what I think it is..those tables are the reason why the russian hacker got nabbed by police. You need those tables in order to decode the (encrypted) data on the disk, but those tables are copyright or IP of some other company (that and the algorithithm)... I am sure I'm wrong about the tables, but it's better just to know that at least *someone* has provided them to you...

okay thanks, so i think i forget it.