Wednesday, August 12, 2009

HTPC info dump

Re: FIXED What causes pixilation on a Satellite feed?

Arrh fixed it, basically there is a virtual tuner created by DVBlink which can be seen in 7MC so you need to change its priority to normal and then change the DVB-S (actual) tuner to use first or highest priority, I had them both set to highest priority meaning they were conflicting and causing nasty pixiliation!! This setting is found in DVBviewer under the hardware tab if anyone is having the same issue.



Acamd works with the native interface in DVBViewer so you don't need anything else in the Plugins folder, just Acamd and its files. If you are using SoftCSA get rid of it and most of your problems should disappear. The includes ffcsa or whatever its called.

I use a fresh install of DVBViewer in its own directory ie c:\DVBViewer1 & c:\DVBViewer2 for the second tuner.

When you install each one make sure you select PROGRAM DIRECTORY for the preferences. This makes each instance standalone. This is also critical to making dual tuners work, otherwise both copies share the same preferences, which is likely to cause havoc.

Also in each DVBViewer make sure you select all the devices that aren't being used to DO NOT USE under Options/Hardware. You should only select 1 tuner for each one, and it should be PREFERRED.


...You just need to adjust the cardclient.conf in Acamd with your IP address, the username/password and the provider id 096A.

Notepad is fine. Just remove the hash from the newcamd line at the bottom and put in your settings.

When your client tries to access a scrambled channel it should connect to NewCS and you'll see a client logon message.

Just one gotcha. Each client connection must use a different username for it to work. So for instance I've got two cards which are set up to allow 3 encrypted sessions each so I use 6 usernames total. These are set up in the NewCS config file which is again a notepad thing.


Protecting pay TV transmissions

Secret key encryption and smart cards are used for example in pay TV applications. Sometimes this is referred to as "conditional access" television. Television programs (usually premium movies, football or soccer matches and adult content) are encrypted using a secret key. To make it difficult for Eve to obtain this key, the secret key is changed every few minutes or sometimes even every few seconds. This way, even if Eve can successfully use a brute force attack to guess the key, she only has a very small portion of the television program. Alice has a set-top box and a smart card that allows her to decrypt the television programs. The set-top box passes the decrypted television program on to the television. Originally these boxes were designed to be placed on top of the television set, hence the name.

Special messages, called Entitlement Control Messages (ECMs), are sent along with the program. These messages contain the secret keys. Of course the ECMs themselves are also encrypted, this time using a key stored on the smart card. Alice's set-top box receives the ECMs and passes them on to the smart card. The smart card decrypts the ECMs and extracts the secret keys contained therein. This allows the set-top box to decrypt the television program.

The keys needed to decrypt the ECMs can be programmed on the smart card in advance. By regularly changing these keys, Alice is forced to purchase a new smart card every month or so. If Eve manages to make a copy of the smart card, or to extract the keys from it, she will only be able to watch the programs for the rest of that particular month.

Another option is to regularly send out so-called Entitlement Management Messages (EMMs) that contain the keys needed to decrypt the ECMs. The EMMs themselves are then encrypted with keys stored on the smart card. The service provider then every month simply sends out a new EMM. This provides much greater flexibility, and Alice does not have to go to the store every month. Every smart card can now have a different key. The service provider sends out different EMMs for all the smart cards in the system. Every EMM thus is readable only by one smart card. If the service provider thinks a particular smart card has been copied illegally, he simply does not send out a new EMM for that particular smart card.


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