System and method for authentication and association of multi-platform accounts

A method of linking, on a blockchain system, a uniquely addressable regulated private wallet of a regulated trading platform with an unregulated wallet on an unregulated trading platform, wherein the unregulated trading platform is resistant to being broken down to (i) identify ownership of individual wallets stored on a public ledger, or (ii) identify a chain of custody of any item stored in its respective unregulated wallet, and the public ledger is configured to store a plurality of unregulated accounts each having at least a unique public wallet address for a user account, the method comprising:

• selectively issuing, using a public certificate module, non-fungible tokens “NFTs” into selectively identified unregulated wallets, wherein each issued NFT is characterised as one of a non-transferable NFT and a transferable NFT;
• in a first unregulated wallet storing:
• a document type identifier with a related minted unique non-transferable NFT linked to an externally generated certificate hash and where the non-transferable NFT is obtained from writing a smart contract and the non-transferable NFT is a permanent record for a description of the document type;
• and
• a link to a first private wallet addressable on the regulated trading platform, the link related directly to the minted non-transferable NFT issued from the certificate module;
• and
• permitting onward distribution of the non-transferable NFT from the first unregulated wallet only through an interaction that directly involves the certificate module;
• and
• permitting the non-transferable NFT in the first unregulated wallet to be changed only through an interaction that directly involves the certificate module;
• and
• wherein system intelligence of the blockchain system otherwise freely allows transfer and change of any transferable NFTs issued to any wallet regardless of a nature of the trading platform.