is there any relation between Biss and Irdeto?

All the conditional access systems (CAS) you mention are typically employed when DVB-CSA is used to scramble the video and audio. They differ in:
1. Biss (version 1) uses a fixed/static 48bit SW (session word) which is expanded to 64 bits by the insertion of two checksum bytes to form the DVB-CSA CW (control word).
2. Every other CAS - you mention only Irdeto and Nagra - uses alternating odd/even CWs which themselves change every cycle. Irdeto, Nagra etc send these cyclic CWs in-stream using encrypted ECMs and card-based/embedded decoding of those in the set top box.

If you are prepared to mount an attack every 10 seconds or so, yes DVB-CSA is completely broken. The only attacks I know of are both plaintext attacks: brute-force trial-decoding of packets marked with the PUSI bit set (slow, 100% success given enough time); and rainbow table trial encrypt on known padding blocks (fast, but encrypted padding must exist inside every crypto period or this attack vector fails).

Me2019H said:

thank you very much for your reply
what i understand from you is if one of the CASs broken the other too will fall
and the Biss is differ from them even if it decrypted we can't broke down the others
but we can open some irdeto channel with Biss Key isn't it!!

Click to expand...

Hard to answer a question that makes little sense from an educated point of view.
You should understand that BISS is a simple encryption system where a single key is used during the whole transmission.
The other system use keys that change periodically.(every ~10 seconds or less)
About breaking systems,BISS key can be found in a relatively small timeframe.
The others work different,where the keys to decrypt video are sent via satellite stream packets,and packets processed to obtain it.
Some systems processes are known and able to open,some are not possible to know.

I think your question goes to the fact that many transmissions are encrypted in the same way,and this way to be known could open all systems,which is true.
I suggest to learn more about how it all works,and all your questions will be answered while you learn.

Me2019H said:

thank you very much kebien




Which lessons do you advice me to follow?

Click to expand...

Look for transport stream and conditional access.
First wikipedia for basics,then more advanced documents.
But do not jump subjects if your intention is to learn,step by step.
There are already too many that think that loading firmware into a receiver makes them a hacker.

Me2019H said:

ok i will Look for transport stream and conditional access to learn
have you a good links?

Click to expand...

Pretty good document on ts

https://tsduck.io/download/docs/mpegts-introduction.pdf