Zk-snarkification of EU ID data. The goal is for European citizens holding a new EU ID card to anonymously prove part of their identity through selective disclosure and zero-knowledge proofs. For that, there are a few parts that need to be implemented. In this repository, we'll provide the code for the proving part of the process. The verification can be done in different programming languages or environments.
This project started at the PSE EthCC[7] hacker house, and the presentation slides can be found here.
Plenty of data is stored on the chips of modern cards. There is the machine-readable zone (MRZ) and the security object (SOD) holding the signature metadata (when it was signed, what the public key is etc.).
One of the easiest (wrt UX) ways to retrieve it is by making use of the card's NFC antenna, which can be read by most smartphones.
A Circom circuit is written and, depending on its inputs, will generate the necessary files for proving parts of the data. This will be done on the smartphone as well, for ease-of-use, as well as to avoid introducing any security issue regarding the transmission of sensitive data (MRZ).
After cloning the repository, go to the circuit's directory and follow the steps in the circuits/README.md file.
At the end you should have a eu-verifier_****.zkey, as well as a circuit.wasm file in the circuits/eu-verifier directory.
You need to copy the .zkey file to the android/app/src/main/assets directory. Also double-check that the .zkey file as well as the circuit.wasm file is still in the circuits/eu-verifier directory.
Aside: If you want to run your own trusted setup ceremony you should check out the circuits/README.md file.
Once that's done, go to the project's root directory and then run cargo run --bin android. This command will generate the necessary bindings for the android app. After this you can build in Android Studio without needing to run a cargo command again. Open the contents of ios or android to build the apps.
To build a release binary use the following commands (run this in the repos root directory):
CONFIGURATION=release cargo run --bin android
As an alternative to the native mobile proving we also created a webapp that allows for proof generation and verification via snarkjs. You can follow the steps in the webapp/README.md file to spin up a local version.