I have an idea and I wanted to ask you if it makes sense… it’s a bit like a proof of ownership or proof of reserve for individuals/companies.
To help bitcoin owners getting advantage of their assets ownership, I was thinking of creating a platform where a user could declare its bitcoin address, the platform challenges the user to verify its claim and edit a certificate that could be “trusted” by third parties like banks.
Proving ownership of an address will need a Bitcoin private key, to sign a message. It's possible to do with a non custodial wallet that gives the user private keys but do you think what will be next steps?
Proving ownership is one step but the actual owner, with private key in hands, can use it to broadcast a transaction and move bitcoin in that wallet (includes that address) to another (other) address(es). This first step is not enough to prevent scam in a trade if there is no Escrow service is used between to sides of a trade.
Your "certificate" means nothing to help a trader partner of that person with bitcoin in a wallet (address) you give the certificate to.