[denart2203]

"However, this system is vulnerable to a very simple threat: a dishonest seller can make a copy of a real bottle with a token, fill it with wine of lower quality, and either steal you..."

The argument around “someone that doesn’t care about tokens” is weak because that applies to any authenticity solution.

The idea behind the authenticity guarantees would be that every step along the way, you add a record that the object has passed through your step. Otherwise I agree this won’t work.

If someone adds a record, but does fill the bottle with cheaper wine, the first person that catches them will blacklist that actor.

[menage]

I don't think you even need a blacklist for this to be of real benefit - if every fancy bottle sold is expected to be accompanied by a blockchain transaction moving the bottle's certificate (originally produced by the winemaker, and unforgeable) then you'll only be able to sell a fancy bottle of wine if at some point in the past you've purchased an equivalent bottle from someone else with a certificate.

There is still the chance that someone along the way consumes the real wine or sells it (at a loss?) to someone who doesn't care about authentication, and then sells on a fake bottle with the real certificate - but:

- at least in that case there would be a well-defined chain of owners that should make it much simpler to figure out who's doing the counterfeiting.

- you can only do this once for each real bottle that you purchase, since you can't forge the certificates.

[azernik]

At which point you're back to a centralized system - who maintains the blacklist and has authority to add people to it?

[SpicyLemonZest]

I don't think that follows. Email and IP addresses both have decentralized yet very effective blacklists against bad actors.