Soulbound is a term derived from the game World of Warcraft, meaning a trait that, once acquired, cannot be transferred or sold to other players. In other words, you will be able to add one attribute to yourself through one acquisition. In reality, personal information that should not be traded, such as nationality, resident registration, academic background, and history, is an example of this. So, how can blockchain prove the contents of such an individual?
You can most easily think of NFTs. As a non-fungible token, NFTs are currently serving as membership in various communities. In Discord, you can use Collab, a wallet integration app, to authenticate NFT holders and grant specific roles within Discord. However, NFTs can be traded. But if you can trade your personal information, wouldn't someone be able to abuse it?
The necessity of the existence of non-tradable tokens has been debated within the Ethereum community.
EIP-1238 : Non-transferable Non-Fungible Token (NTT)
EIP-4671 : Non-tradable Token
However, these proposals did not lead to utilization. However, recently there has been a lot of discussion again through EIP-4973 (Account-bound tokens). Vitalik Buterin is the author of the paper, and co-author E. Glen Weyl is excited to announce that it will be available at the end of 2022.
These non-transferable tokens will solve the problem that Web3 today focuses on expressing transferable financial assets rather than encoding social relationships of trust, increasing sociality and increasing returns on social relationships. It can also avoid today's over-financialization for a pluralistic future.
