[Acidstorm]

C & P

Easier Way To Understand A Map Call

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First how digital scrambling works, quick version.
A digital picture or audio, is simply a bunch of numbers, when put together they make up the picture you watch or audio you hear.

Digital scrambling is easy you simply mix up the numbers, but to unscramble the picture you must know how it was scambled.
All sat TV providers use the same system to scramble, its called a Control Word system, easy term, they use a number like 03 c2 51 da 35 f5 ef 76 to scramble ONE channel for about 2 minutes, then they change the number, this number is called the CW (control word), they use a different number(CW) for each channel, it is just a random 8 byte number.

After they have Scrambled the video with the CW number it is unwatchable, so their subscribers can't watch it either, so they must send out the CW to all their subscribers, and THIS is where encryption and decryption comes into the system.

This is what a card or cardless software is for, decrypting the CW for a specific channel, this is also why some channels will work and others won't, more on that later.

Ok so the picture is Scrambled using a random number called the Control Word(CW).
Now to prevent anyone with a dish and digital receiver from watching their channels the provider must encrypt(hide) the CW using different prearranged math methods, the prearranged part is what they have loaded on their subscribers cards or receivers, they encrypt the CW using the reverse of the prearranged decryption on the cards, and this is where MAPs come into play.

A MAP is nothing more, or less, than a preset math formula.
add 03 to all numbers
sub 06 from all numbers
multiply all numbers by 04

All 3 of these are simplified math versions, each its own MAP.

So
MAP01 = add 03 to all numbers
MAP02 = sub 06 from all numbers
MAP03 = multiply all numbers by 04

Real MAPs are a little more complicated mathwise, lol.

But the process is the same, a MAP changes the CW number in a known way, known to DN.

DN tells the cards to use MAP57, then MAP03, then MAP3B in that order to decrypt the CW, if you don't know what the MAP does to the CW or you do it in the wrong order then you get the wrong CW at the end an no picture.
They also throw in a key or two (auto-roll gets one of those keys) in the decryption process just to make it a little more secure.

So pretty straight forward process, nothing real complicated about it, and very secure IF your cards are secure. This is why DTV is no longer a "freeTV" option, their new cards are secure.
There is no way to get around this type of scrambling you can either get the correct CW or you can't, the problem is the CW changes every 2 min. on each channel and no two channels will have the same CW.
You aren't going to just "guess" the CW for a channel, and even using the fastest computer on the planet you couldn't beat the 2 min. cycle.

If you read something that says they can beat this type of system without inside the card info, then put your hand on your wallet and back out of the room slowly, lol.

Because each channel basicly is running its own CW encryption they can run some channels on one CW encryption and other channels on another CW encyption, BEV is even using a different base system for NFL.
At any given time there are usually 2-4 different decryption paths available on a card, at this time BEV has 2-6.

In theory there could be 256 MAPs in a DN card, MAP00 to MAPFF, but probably not.

Just FYI, N1 and N2, and for that matter N3 when it comes, use the same scrambling of the digital picture, only the way the CW is Encrypted and decrypted changes, so they can run multiple types of encryption at the same time, its only a few more CW packets every few minutes there is no bandwidth issue.

Now what has happened as of late, is that (Nagra Vision) has started impelmenting N3 into the stream, this itself is why we have all started seeing (private keys) example: nagra 01 06 00,for DN and B*V and 09 05 00,09 06 00,an 09 07 00.
Most of the time these's keys are not active, but as of late BEV and Charlie's are trying to see just how far they can push there own receiver's and still work, most times itself is not but for a few hours at a time. but they are still continueing to work on it, making everyones life hard, including there own customers ofcourse.

Just remember that, unless BEV and Charlie's does a (complete system wide) upgrade of there whole (equipment, CAD Cards and Codes) at a cost of possibly a billion US dollars, only then can it shutdown FTA, and stop any coders from writting codes for all FTA units.

I hope this will explain things a little better.

[cdo_care]

Thanks for the Great INFO.....Hope everyone will read this Post.

[tnc917]

so what is needed now to watch tv?

[Ladybbird]

Originally Posted by tnc917

so what is needed now to watch tv?

A remote


Especially with great guys like AS working in our corner.





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[Ladybbird]

Acidstorm thank you thank you thank you so much. I have always wanted to know how they blocked fta, your explanation was really easy to understand. (My brain must be healing). It is reassuring to know it will cost them billions of $$$ to stop fta.

Great informative thread. I hope more folk contribute after reading this, it may make them appreciate our gurus like you a little more.


LB



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[Acidstorm]

It seems i did not search well enough, this was , posted already sorry!

MAPCALL MADE SIMPLE!

[Ladybbird]

Well Im glad you did AS, cos I missed the first posting and I learnt a lot from it.

[woodcreeker]

Not a biggy, Acid. I have seen good posts like this crop up over and over.

I can correct some of the information, though. DTV is no longer secure, just so everyone knows. I do not know if any of the coders are actually going to add DTV to their bag of tricks. Time will tell, as this is a new development. With FTA receivers being programmable, they could easily be coded for DTV testing.

Also, DN and/or BEV replacing receivers will only shut down much of the currently used FTA receivers, but not all. And we all know they will produce a different generation of FTA receivers if they did, and at a very rapid rate I would bet.

Either way you look at it DN and BEV is running around spending oodles of money for nothing. I remember in the DTV days when DN thought their encryption system was impossible to break. That state of security didn't last long, either.

I would go out on a limb and say everything will get broken faster and faster until the providers next generation of satellite equipment is broken, they will simply have to give up on it all. This all remains to be seen of course. The game is still on for now.

[tnc917]

so if i have a SV 4000 when Nagra 3 comes in effect i will go blank? and if so will it ever work on a new program or just trash it?