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Whenever the key is checked, the software that checks the key creates an entry in the blockchain. Using your example of a Rolex, the code can be scanned by the

by 2cb 5y ago

Whenever the key is checked, the software that checks the key creates an entry in the blockchain. Using your example of a Rolex, the code can be scanned by the authorised dealer and buyer. Those events are then stored in the blockchain next to the cryptographic hashes of both entities. Any authorised dealer who buys one for resale would scan the QR code so ownership can be transferred in the same way on a public ledger. If there's a public record that this Rolex has been purchased already and you scan it, this record would show up. It could even show exactly where and when it was purchased. Clearly, for someone to put a real cryptographic key on a fake Rolex, they need to have taken it from a real one. So if someone tries to sell you a "Rolex" and you scan it, you'll have the history of the watch right there. If they try to claim it's new, you'll know that's a lie. If they try to sell it to an authorised dealer, they'll get caught. This could still leave space for fake Rolexes to be sold as used on eBay or something of course, but then if you buy a "Rolex" on eBay from a random seller (not an AD) you kind of know what you're getting already don't you? (Although even in those situations, knowing exactly when and where the real watch was last purchased makes it easy to just make a phone call and get a better idea of legitimacy. Currently, even ADs send the watches to Rolex for verification because the fakes are so good.)

mytherin 5y ago
Your example seems to be mostly coordinated through Rolex and authorized dealers, so what is the advantage of a blockchain? Why not just have Rolex keep track of who owns a watch through e.g. a web interface tied to a serial number + username/password combination, that also allows transferring of the ownership of a watch to a different user? This would be much more user friendly, since you could have features such as "forgot my password" which are (by design) impossible to implement on top of a blockchain.
dmitriid 5y ago
> Whenever the key is checked, the software that checks the key creates an entry in the blockchain. Right. So on top of a blockchain there's some software that inputs something on the blockchain. What's to stop me from creating software that won't create those events, but will still check the key? > Any authorised dealer > so ownership can be transferred in the same way Curioser and curioser. So now there are centralised dealers that can transfer ownership. So only selected few can create events on the great decentralised blockchain. Tangential question: if I want to give the watch as a gift, do I have to have Rolex's blessed authorised software to do that? Also, if "authorised dealers" have the power to do this, it means they have the cryptographic keys. This also means that the rest of the world has them. > So if someone tries to sell you a "Rolex" and you scan it, you'll have the history of the watch right there. Indeed. So, the counterfeit watch comes up with a real history. Rolex produces almost a million watches a year. It will be ridiculously easy to pick up numbers for the counterfeit watches that are new. Those that are not "new" can be sold at second hand markets. > but then if you buy a "Rolex" on eBay from a random seller (not an AD) you kind of know what you're getting already don't you? Ah. And here it is: "blockchain can help verify authenticity with near 100% certainty" devolves into "you know what you're getting into" in the span of three comments.

by 2cb 5y ago

mytherin 5y ago

Your example seems to be mostly coordinated through Rolex and authorized dealers, so what is the advantage of a blockchain? Why not just have Rolex keep track of who owns a watch through e.g. a web interface tied to a serial number + username/password combination, that also allows transferring of the ownership of a watch to a different user? This would be much more user friendly, since you could have features such as "forgot my password" which are (by design) impossible to implement on top of a blockchain.

dmitriid 5y ago

> Whenever the key is checked, the software that checks the key creates an entry in the blockchain. Right. So on top of a blockchain there's some software that inputs something on the blockchain. What's to stop me from creating software that won't create those events, but will still check the key? > Any authorised dealer > so ownership can be transferred in the same way Curioser and curioser. So now there are centralised dealers that can transfer ownership. So only selected few can create events on the great decentralised blockchain. Tangential question: if I want to give the watch as a gift, do I have to have Rolex's blessed authorised software to do that? Also, if "authorised dealers" have the power to do this, it means they have the cryptographic keys. This also means that the rest of the world has them. > So if someone tries to sell you a "Rolex" and you scan it, you'll have the history of the watch right there. Indeed. So, the counterfeit watch comes up with a real history. Rolex produces almost a million watches a year. It will be ridiculously easy to pick up numbers for the counterfeit watches that are new. Those that are not "new" can be sold at second hand markets. > but then if you buy a "Rolex" on eBay from a random seller (not an AD) you kind of know what you're getting already don't you? Ah. And here it is: "blockchain can help verify authenticity with near 100% certainty" devolves into "you know what you're getting into" in the span of three comments.