Document Authentication on the Blockchain

I used to see services that let you notarize docs on the Bitcoin blockchain. Just upload a file, and boom, the hash gets saved. It's a neat way to show you own something. Does anyone know if there's a similar thing for Ethereum or any EVM chains? Can NFTs help with that? I'd love to hear your thoughts.

You might wanna check out ZK-Passport. It works with biometric docs only, so no old-school passports. They use ZK-SNARK for data encryption and it's in early use for KYC. Heard the Ethereum Foundation backs them too.

ZK-Passport's more about ID verification with ZK tech, not exactly what I meant by "notarizing". I’m talking about putting the hash of a document on-chain for proof of ownership. Just a hash, not the whole document. NFTs might do it, but gas fees can be a killer when ETH is busy. Not sure it's worth it.

Smart contracts could probably handle this. But with actual legal proof of ownership, I'm skeptical. Too many documents leak out, you know?

Totally agree, notarizing via blockchain with NFTs sounds amazing since it’s all immutable. But legal recognition is the snag, plus we still need human notaries too. If the gov can jump on it, maybe in a year or so, but let’s be real, they move slow.

I've got a prototype that anchors hashes to the chain. Currently testing on Polygon Amoy for low costs. It's faster and easier than old methods. Not ready to share the link yet but hit me up if you want some technical details.

That’s interesting! If it runs on Polygon, can it work on other ETH L2s too?

Yeah, I heard they’re planning to use this tech for all kinds of document verifications in the future. And fees on Ethereum have improved, not much of a problem now. ZK-rollups are likely gonna make it even cheaper.