I was just wondering how they restrict what travels to your specific home(or apartment in my case). No, I'm not considering stealing cable. I was thinking about it because we just had a technician in our house and I came up with the question. I've done a lot of research on google and can't really get anything out of it. Any help would be great!
They send most of the channels to your box encrypted. To decrypt them, the provider sends a message to your box (encrypted with a key for your box) with the keys needed to decrypt the stream keys for the channels and features you subscribe to; the stream keys used to decrypt the transmitted channel stream. If you unsubscribe from a channel or tier of channels or change your package, the provider just sends a new message with new keys for the packages, deleting the old keys (or sending unsubscribed channels as null keys). The Tier keys are updated monthly, or even more often, so that if the box does not get a de-auth message, that the keys in it become stale and won't work to decrypt key streams.
Normally they will install a filter on your cable line which allows only signals you are paying for to go through.
Your box gets ALL the channels; however, the tuner will only decode the ones for which you have access.
