22. Decentralized Identity, Reputation, and Naming

today your online identity is a set of accounts that companies own and lend to you, and your personal data lives in their filing cabinets, not yours. This is convenient and fragile at the same time. You cannot move your reputation from one platform to another, you can be evicted from your account without recourse, and you bear the consequences when someone else's filing cabinet is robbed.

self-sovereign identity is the goal of carrying your own verifiable "ID cards" in a digital wallet you control, showing them directly to whoever needs to see them, and revealing only the specific fact required. It is a statement of principle about control and privacy, not a particular piece of technology — and certainly not synonymous with "put it on a blockchain."

a DID is a self-issued name you control with a secret key instead of a password, and that no company can take away. Crucially, a DID does not have to live on a blockchain — some do, many do not. The W3C blessed the standard in 2022, but only over the objections of Google, Apple, and Mozilla, who thought it was not yet ready — a useful reminder that this is frontier technology, not settled infrastructure.

a verifiable credential is a tamper-proof digital certificate that anyone can check without phoning the issuer — and, with the right cryptography, you can use it to prove a single fact ("over 18," "licensed," "employed here") while hiding everything else. Like DIDs, credentials do not need a blockchain to work; the blockchain, where used, is a supporting cast member, not the star.

ENS is a phonebook for crypto, turning an unmemorizable address into a name like alice.eth. Unlike a normal web domain, you hold the name in your own wallet, so no registrar can easily take it — though you still typically pay to renew it, and publishing a name-to-money map for all the world to read carries its own risks.

soulbound tokens are badges you earn and can never sell, so possessing one actually proves something about you — a digital merit badge or diploma that is worthless to a thief because it only works on its rightful owner. The grander idea, DeSoc, is to build a "social layer" for Web3 out of such badges. It is a thoughtful proposal and an unbuilt one, and it carries an obvious dark side: a permanent public record of who you are and whom you associate with.

a public ledger is wonderful for proving who paid whom and terrible for holding who-you-are, because it never forgets and everyone can read it. Put your identity on it and you cannot later erase a mistake, and anyone who once links your pseudonym to your name can read your whole life. This is why the people who actually wrote the identity standards say: keep the personal data off the chain.