From Trade-only to Zero-Value NFTs: The Asset Proxy NFT Paradigm in Web3

Many implementations of smart contracts available in NFT marketplaces today allow the modification of NFT token attributes, without any specific mechanism to control the consistency with off-chain metadata. We believe this is a weakness in overall design of NFTs today. We propose a computation model called the Asset Proxy NFT that guarantees the consistency between the NFT token (on-chain) and its corresponding asset metadata (off-chain). In general, the proposed model can be applied to any type of NFT that requires immutability or controlled mutability of metadata. A second contribution of this paper is the notion of the NFT design patterns which recognizes that a coherent framework for dealing with hybrid assets is required, and that for specific hybrid-asset deployments, suitable technological components must be utilized under the framework.