Earlier quoted context omitted.
Surely chain of custody applies if the accused has access to the evidence? Perhaps I’m missing your point or I’m overly optimistic about the legal system.
Suppose the store manager is having a dispute with a kid who keeps skateboarding in the parking lot, so the store manager decides to commit insurance fraud by robbing the store herself and then submits forged video of the kid doing it to the police. The store manager is in the chain of custody but isn't a suspect, the accused is the kid. The kid doesn't even know who actually committed the crime. How is the kid suppo…
There are some experimental specifications that exist to provide attestation as to the authenticity of media. But most of what I’ve seen so far is a “perjury based” approach that just requires a human to say that something is authentic.