Maybe the bit of the data containing Amu's personality framework? That SHOULD have a valid local manufacturer.
Right. Certificate primer time!
Public-key encryption allows you to do two related operations. One of them involves encryption; the other, signing. I'll be focusing on the signing...
Step 1: Generate a public/private key-pair.
Step 2: Publish the public key.
Step 3: Sign some message with the private key. Anyone who knows the public key can then verify that you knew the corresponding private key.
But there's a problem here: How do you know that the private key belongs to the person you think it does?
The solution is certificates. Some more-trusted party can create a "certificate" - a block of text saying, basically, "<This public key> belongs to <this person>". It is assumed that they've performed due diligence in making sure that's true. If they then sign it, then you can (theoretically!) be sure that they
did, in fact... sign it. There's no way to fake a signature, and in theory that's all that's needed.
That depends on you trusting said more-trusted party, however. If you don't, then you're right back at the starting line. The solution for that is for some even-more-trusted party to sign the more-trusted party's certificate...
You can see how this might lead to a chain of certificates, but in the end there has to be some key that's trusted "just because".