Optical discs are prone to damage, and for this reason, they usually store data encoded with an error correcting code.
While day-to-day use for optical storage media has diminished in recent years, they continue to be used for distribution of movies and TV shows, given they have special value to collectors. In such applications disc content is usually encrypted to protect copyright, which begs the question, what are the requirements for their decryption to be successful?
Now let me formulate a scheme, with layers consisting of error-correcting codes and ciphers.
Before data is burned onto a disc, it goes through 3 layers:
Inner-layer error correcting code,
Outer-layer error correcting code.
The tricky part is encryption. It seems that only a stream cipher can be used, otherwise the inner-layer error correcting code will be meaningless when the decryption fails. As such, deterministic authenticated encryption and key-wrapping ciphers cannot be used here. So a stream cipher must be used, and nonce must receive extra protection against potential errors in the outer-layer error correcting code.
My question is: if there's an inner-layer error correcting code, will it be able to work without an encryption algorithm based on a stream cipher? How do DRM-protected discs usually protect its contents from theft and physical damages?