Is end to end encryption even beneficial in a public broadcast medium? I mean, you’d need to send the encryption key as part of the broadcast. There isn’t an out of band channel to transmit a key, so how could this even work in a secure way? Or will they require an internet connect for key distribution? That seems antithetical to the purpose of broadcast TV.
Signing the signal is all you need to be able to validate that the signal came from the broadcaster. But even this assumes that the public key will be transmitted often and the rogue pirate broadcast a bad key.