Glossary
Uniqueness Proof
A uniqueness proof demonstrates that a specific principal hasn't already participated in something — cast a vote, claimed a limited offer — without necessarily revealing who that principal actually is. This is a narrower and often more appropriate requirement than full identification: for many uniqueness-sensitive actions, what genuinely matters is that no one participates twice, not that the system knows exactly who each participant was.
This is a different authorization shape from most of what typically gets designed for, which usually starts from verifying identity and then checking that identity's specific permissions. A uniqueness proof instead asks a narrower, structurally different question — has this specific token, credential, or proof been used before — that can be answered without ever needing to know or record who's actually behind it, which is precisely the property that makes genuinely anonymous voting or genuinely anonymous limited-offer claims possible at all.