May be a dumb question but how can we certify that the same asset doesn’t exist as two or more NFTs on different block chains. There are tons of them and each can have its own monalisa.
> how can we certify that the same asset doesn’t exist as two or more NFTs on different block chains
You can't. But surely some wise guy is pitching a blockchain for that right now.
It's actually worse, the same certificate could exist on multiple blockchains, and none of them guarantee approval by the original artist; all could be legally void certificates of nothing.
It's a good question. In practice, a project will publish the official contract address and the chain on their web page.
Hence, it becomes a schelling point for users. It assumes that the project owners are in control of their servers and DNS. For users, there is then just one official contract, regardless of how many others are published and on different chains.
As an aside, there is ENS, which people are starting to use to say they own a DNS domain https://docs.ens.domains/dns-registrar-guide. ENS itself is an NFT, so it's turtles all the way down.
