Legal Fishing

This Github repo demonstrates how one could set up a Fluree ledger to use zero-knowledge proofs.

In this example, Fluree is deployed as a backend data management platform in managing trusted data. The use-case is a simple example of:

1. the establishment of a dynamic zone where fishing is allowed
2. the ability for boats to input catch locations without disclosing where the catch was precisely made
3. the ability for a third party to validate that the fish was caught in an allowed zone, without disclosing their catch location

Please check out the accompanying blog post and video !

Features demonstrated: zero knowledge proofs, data immutability, and traceability.

Get Started

1. Start Fluree

Download and unzip this Fluree packet. The packet contains Fluree, version 0.13.0, as well as a prepopulated database with the schema, seed data, and several example proofs (resources/schema.json and resources/seed.json have the schema and seed transaction, respectively).

Navigate to the folder where you downloaded the packet, and run ./fluree_start.sh. If you have Java 8+ installed, this should launch Fluree, and a Admin Console will be available for you to explore at http://localhost:8080. resources/example_queries.js has example queries you can test out directly in the Admin Console.

2. Start the App

git clone https://github.com/fluree/legal-fishing.git

cd legal-fishing

npm install

npm start

How Does it Work

Zero-knowledge proofs allow you to prove that your secret information fits certain parameters without sharing your secret information. We used Iden3's circom to create the circuit used in this app, and Iden3's [snarkjs] to handle proof generation and verification.

Please check out the accompanying blog post for more information about the zero knowledge proofs used in this example.

Query to Get Circuit

This app uses a single circuit, which we use to generate all the proofs. We store the circuit, proving key, and verification key in the snarkConfig collection under the id legalFishing. We use the below query to fetch the circuit and proving key.

{   "selectOne": ["?circuit", "?provingKey"],
    "where": [
            ["?snark", "snarkConfig/id", "legalFishing"],
            ["?snark", "snarkConfig/circuit", "?circuit"],
            ["?snark", "snarkConfig/provingKey", "?provingKey"]]
}

Transaction to Submit Proof

The below transaction is used to create a new proof, and link that proof to the snarkConfig, which is storing the relevant circuit and keys.

[{
    "_id": ["snarkConfig/id", "legalFishing"],
    "proofs": ["proof$1"]
  }, 
  {
    "_id": "proof$1",
    "proof": "PROOF HERE",
    "instant": "#(now)",
    "publicSignals": "PUBLIC SIGNALS HERE"
  }]

Query to Get All Proofs Connected to the legalFishing Circuit

The below query gets all the proofs that are connected to the legalFishing circuit.

{
    "select": ["?proof", "?proofBody", "?publicSignals", "?verificationKey", "?instant"],
    "where": [
                    ["?proof", "proof/proof", "?proofBody"],
                    ["?proof", "proof/publicSignals", "?publicSignals"],
                    ["?proof", "proof/instant", "?instant"],
                    ["?config", "snarkConfig/id", "legalFishing"],
                    ["?config", "snarkConfig/verificationKey", "?verificationKey"]
    ]
}

There are other example queries that you can try out in /resources/example_queries.js.

Visual Studio Code

If you are using Visual Studio Code to view this repo, you can issue the example queries using the extension.

1. Download the Fluree: Beta extension. In the top menu bar, select View > Extensions. Then search Fluree: Beta and click install.
2. Open the Command Palette by going to View > Command Palette, and issue Fluree: Set Config.
3. Highlight any query in resources/example_queries.js, using the Command Palette, issue, Fluree: Query, and the results of the query will appear in a flureeResponse.txt file. Note: every time you issue a query or transaction, this file gets overwritten.

Resources

To see more example projects, visit our example repo.

This example also has an accompanying blog post and video.

Check out our entire documentation or jump directly to the section on full-text search.

You can also engage with us via email, [email protected].

Or by Slack.