Why Have My Stamps Expired?

Stamps expire every 90 days. This expiration policy serves two purposes:

1. Maintaining confidence — Regular reverification ensures that Stamps still reflect your current credentials and identity.
2. Increasing Sybil attack difficulty — Expiration forces attackers to continuously re-verify, making sustained Sybil attacks more costly.

Additionally, expiration allows users to reassociate Stamps with a different wallet if needed. After a Stamp expires on one wallet, it can be claimed on another.

When your Stamps expire, simply revisit the Passport app and reverify them to restore your score.