World ID Reset
World ID 2.0 allows a user to reset their World ID in case their World ID has been lost or stolen. The user reverifies at the Orb, and their old World ID is invalidated. The user is then issued a new World ID and this new identity is verified at the Orb. A user will not be able to perform a World ID Reset more than once every 14 days.
When a user signs in with World ID, their Nullifier Hash is returned as the
sub claim in the ID Token. Recall that the Nullifier Hash is the unique identifier of a user in the context of a specific action -- a different identity will return a different Nullifier Hash.
A second sign-in method, such as an email address or phone number, is highly recommended to ensure that the user can continue to use their account in the event of a World ID Reset. The user should be able to verify that second factor after a World ID Reset and link their new World ID to their existing account.
When a user performs a World ID Reset, they are issued a new World ID and their old World ID is invalidated. This means that any Incognito Actions performed by the user will no longer be associated with their new World ID.
We recommend using time-bound sybil resistance in your application to mitigate the impact of a World ID Reset. Time-bound sybil resistance requires a user to verify with World ID periodically, rather than a single verification lasting indefinitely.
Time-bound sybil resistance is used for Worldcoin Grants, where a new grant is issued every two weeks. Every grant is a new action in World ID, requiring a separate World ID verification to claim each grant.
As another example, a social media application may use World ID to mark a user's account as verified. The application could require the user to perform a new verification every 30 days to maintain their verified badge. In this situation, a user who performs a World ID Reset may be able to mark a second account as "verified" immediately after performing the reset, but will only be able to verify a single account at the end of the 30 day period.