This would effectively mean that every manufacturer were a retailer, because they would need a direct relationship with the ultimate buyer. Whether you like Ama

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....