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  1. Data Vault
  2. Proving Schemes

Hydra-S1

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Last updated 1 year ago

The Hydra-S1 proving scheme is the first proving scheme in the Hydra family:

  • Hydra = using Hydra Proof of Ownership via the

  • S1 = single source, version 1: verifying membership in a single

Currently, the proving scheme is utilized by the ZK Badge protocol, which is no longer maintained. It allows users to verify membership in a Data Group from a single Data Source and mint a ZK Badge on an unlinked Ethereum address.

Sismo’s uses Hydra S1 proving schemes to issue ZK Badges. You can see them . While the contracts are still deployed, Sismo no longer maintains the ZK Badge protocol. Read more in this .

Hydra Proof of Ownership

The Hydra-S1 proving scheme allows participants to establish, in one ZK proof, that for a given Proof Identifier:

  • They own 2 accounts (source and destination)

  • The source account is part of an

  • The source account was registered in the with a specific value

  • A claim about their source account value is true

    • e.g: "my account value is superior to 5" (non-strict claim)

    • or "my account value is strictly equal to 5" (strict claim)

  • They correctly generated a Proof Identifier

A Proof Identifier functions as a nullifier for the Hydra-S1 proving scheme, preventing the same user from minting a certain ZK Badge more than once.

Commitment Mapper
Data Group
ZK Badge protocol
here
blog post
Accounts Registry Tree
Accounts Registry Tree