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0 pointsghostly_s1y ago0 comments

Are OTA channels subscription based where you are (where)? Or the "decoder card" is just some middleware crap you buy once? Our OTA TV has always been ad-supported, they just moved the same channels to digital though in larger markets there are now quite a few new low-overhead licensed syndicated content options, presumably due to the cheaper cost of air slots.

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perching_aix1y ago

It's a subscription, billed monthly, with a minimum one year contract period. To the best I can tell, the service provider is in a completely monopolistic position too (is the only digital OTA (analog has been banned, and OTA is more commonly referred to here as terrestrial) television broadcaster in the country and is privately owned), so yeah, good fun all around.

I looked into it a bit deeper inspired by this thread, and it seems to be an explicit feature of the European digital TV broadcast system standard (DVB-T) [0], commonly used not just here in Europe, but also elsewhere around the world apparently [1].

The formal name for the "decoder card" I recalled is apparently CAM [2], which communicates with the TV using the DVB-CI protocol(?) [3], and uses the form factor of the old PCMCIA cards. I also see that the algorithm used is the CSA [4], and even more curiously I see mentions of DES [5] in the article for the encryption (with further mentions that AES is a new addition to the standard that is presently underadopted).

The only vendor-specific bit to this, because there is a bit that is vendor-specific, seems to be the key exchange algorithm used, although the articles are unclear to me about this. Interesting subject for sure. Here where I live, the Conax system [6] is in use supposedly. To be clear, they're not the service provider and have nothing to do with them (to the best I can tell).

Addendum:

Apparently I misinterpreted how it works a bit. So the Conditional-Access Module is plugged into the TV, so far so good, but that on its own is not going to achieve anything. The actual unlock comes from a smart card bundled with the CAM, and you're to put that into the CAM. As you can tell, we've only ever watched the free channels :)

[0] Digital Video Broadcasting - Terrestrial, https://en.wikipedia.org/wiki/DVB-T

[1] https://en.wikipedia.org/wiki/File:Digital_terrestrial_telev...

[2] Conditional-Access Module, https://en.wikipedia.org/wiki/Conditional-access_module

[3] Digital Video Broadcasting - Common Interface, https://en.wikipedia.org/wiki/Common_Interface

[4] Common Scrambling Algorithm, https://en.wikipedia.org/wiki/Common_Scrambling_Algorithm

[5] Data Encryption Standard, https://en.wikipedia.org/wiki/Data_Encryption_Standard

[6] https://en.wikipedia.org/wiki/Conax

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