Books are published - either by a publisher, or by the author. That's the equivalent of a 'checksum'.
The author should be able to provide to Amazon/Goodreads a list of publishers for their book. Any publisher not on this list should be prevented from selling the title.
If someone wants to impersonate an author, they'd have to also impersonate a publisher - a much bigger legal risk.
Not really: unlike traditional publishers, Amazon presents itself as just a printing on demand service. They don't have any objective in policing users of their service.
The author should be able to provide to Amazon/Goodreads a list of publishers for their book. Any publisher not on this list should be prevented from selling the title.
If someone wants to impersonate an author, they'd have to also impersonate a publisher - a much bigger legal risk.
Simple solution.