I wouldn't trust that they are who they say they are unless they can prove it. Also I don't trust anyone between them and me, including Amazon.

If they signed products with a cryptographic key, might actually be worth something as proof of who they are.

Why would the manufacturer bother instead of just telling you to not buy on Amazon and buy directly from them? On any expensive item that people research it seems like it'd be in their interest if Amazon got a reputation for selling fakes, to break the habit of people who only look on there.

This would effectively mean that every manufacturer were a retailer, because they would need a direct relationship with the ultimate buyer. Whether you like Amazon or not, that kind of retail model has proven incredibly valuable to shoppers by aggregating sellers that would be too hard to find individually and eliminating the need for a manufacturer-end-buyer relationship.

A solution like this would also limit alienability of property. I buy a DSLR and register it with the manufacturer. Two years later I want to resell it to someone else and discover my manufacturer either refuses to issue the new QR code to the buyer, or wants to charge a "reasonable" or "nominal" fee of 25% of the fair market value of the good to effect the transfer.

This is why a distributed-trust solution like blockchain actually might not be overkill, in spite of its buzzwordiness these days.

Or to return to your idea, instead of the person's name, transfer to an ID that's backed by another keypair. The buyer now has the authority to sign away full ownership without asking the manufacturer for cooperation. Of course, this means the manufacturer and each seller in the chain now has to have a tech-support department for people who lost their private keys or forgot the keychain password....

The digital signature of the serial number would probably be sufficient. That’s not a bad idea.

An idle thought perhaps not well thought out. But I was envisioning more than the simple Manufacturer to Amazon handoff, something like a new type of individual-item-specific UPC where you could continue to track ownership even through hip-to-the-system OfferUp style apps. The privacy implications are scary, and I'm not suggesting there's a viable or good idea in here. Thus it was a question. :-)

Alibaba disagrees. Amazon should take a look.

https://medium.com/@alitech_2017/blockchain-based-qa-the-end...