Isn't this the sort of thing digital signatures are for? Author can sign the text of the book, and publishers can sign the container. I don't know how future-

Isn't this the sort of thing digital signatures are for? Author can sign the text of the book, and publishers can sign the container. I don't know how future-proof this is (and it obviously isn't going to work for something like War and Peace), but it's something that can be done today.