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The only thing I can think of is embedding a physical unclonable function into the thing. As long as Nike holds on to custody of the physical tokens and only em

The only thing I can think of is embedding a physical unclonable function into the thing. As long as Nike holds on to custody of the physical tokens and only embeds them in real Nike products, then you could verify with the Nike database that it's a real token and a real product. But you don't need a blockchain for that. https://en.m.wikipedia.org/wiki/Physical_unclonable_function https://en.m.wikipedia.org/wiki/Physical_unclonable_function

chrisco255 6y ago
Sure you do. Nike could go out of business and their records lost forever. Nike could suffer a hack. Nike could have a rogue employee manipulate the database values. Nike could be thrown off the internet by AWS. A public blockchain like Ethereum is plausibly neutral, decentralized into tens of thousands of nodes worldwide who carry copies of the ledger, and there is a strong economic incentive baked into the blockchain to keep blocks consistent and persistent. And if you want to trade your Nike NFT with someone's Reebok NFT, it would help to use an open standard with an economic mechanism for trade between counterparties built-in.
- roywiggins 6y ago
  Nike can just produce a set of PUF keys, cryptographically sign that list, and publish it. Then they embed one of these into a bunch of otherwise identical Nike products. The message could also describe the product's physical attributes so someone couldn't swap a PUF between differently-rare Nike products. Knowing the PUF key doesn't let you fabricate a physical widget with the same key (that's the unclonable part). So they can all be public, and anyone can keep a copy of the batch of PUF keys that includes their object's PUF key. When they want to prove it's an authentic item, they can prove the PUF produces a key on that list and prove the list was signed by Nike by normal public key cryptography. In this scheme, Nike published their public key in an SEC filing, so in the worst case you can go ask the SEC for it. Nike could also stick a copy of their public key in every product and advertisement they make if you want to be paranoid about verifying this in 50 years. This seems more bombproof in some ways than relying on Ethereum to keep existing and well-governed.

chrisco255 6y ago

Sure you do. Nike could go out of business and their records lost forever. Nike could suffer a hack. Nike could have a rogue employee manipulate the database values. Nike could be thrown off the internet by AWS. A public blockchain like Ethereum is plausibly neutral, decentralized into tens of thousands of nodes worldwide who carry copies of the ledger, and there is a strong economic incentive baked into the blockchain to keep blocks consistent and persistent. And if you want to trade your Nike NFT with someone's Reebok NFT, it would help to use an open standard with an economic mechanism for trade between counterparties built-in.

roywiggins 6y ago
Nike can just produce a set of PUF keys, cryptographically sign that list, and publish it. Then they embed one of these into a bunch of otherwise identical Nike products. The message could also describe the product's physical attributes so someone couldn't swap a PUF between differently-rare Nike products. Knowing the PUF key doesn't let you fabricate a physical widget with the same key (that's the unclonable part). So they can all be public, and anyone can keep a copy of the batch of PUF keys that includes their object's PUF key. When they want to prove it's an authentic item, they can prove the PUF produces a key on that list and prove the list was signed by Nike by normal public key cryptography. In this scheme, Nike published their public key in an SEC filing, so in the worst case you can go ask the SEC for it. Nike could also stick a copy of their public key in every product and advertisement they make if you want to be paranoid about verifying this in 50 years. This seems more bombproof in some ways than relying on Ethereum to keep existing and well-governed.