Zeth - Zerocash on Ethereum

🚨 WARNING This project is a Proof of Concept. It is highly inefficient and has not been thoroughly reviewed. Please do not use in production!

Disclaimer: This work is inspired from babyzoe, Miximus. It follows and extends the design presented in zerocash-ethereum by adapting some code initially written by Zcash.

👉 Check our paper for more information about Zeth.

Building and running the project:

Environment

In order to follow the README below, you will need:

Docker
Npm (at least version 6.4.1)
Node (at least version v9.5.0)
Python3 (at least version 3.7)

We use 3 terminals to run the project. One terminal will be used to run the proving service/server, another one will be used to run a local Ethereum testnet, and the final terminal will be used to run a python stub that triggers a few proof generations on the proving server in order to do confidential transactions on the Ethereum testnet.

The titles of the sections below are prefixed with the terminal ID the commands should be ran into.

Terminal 1: Configure the project and run the cpp tests (Docker)

# Clone this repository:
git clone git@github.com:clearmatics/zeth.git
cd zeth

# Pull the zeth-base image (built from `Dockerfile-base`)
docker pull clearmatics/zeth-base:latest
# Build the zeth-dev image
docker build -f Dockerfile-zeth -t zeth-dev .
# Start the zeth development container
docker run -ti -p 50051:50051 --name zeth zeth-dev:latest

## All the commands below are ran in the docker container
# Configure your environment
. ./setup_env.sh

# Compile the proving server
mkdir build
cd build
cmake .. [<flags (see below)>]
## (optional) Run the tests
make check # Builds and run the tests (once the tests are built, calling "make test" suffices to execute them)
## Compile
make

# Start the proving server
prover_server

Note: flags in the cmake command may include -DCMAKE_BUILD_TYPE=Release for an optimized build.

Build Options

By default, zeth makes use of GROTH16. To chose a different zksnark run the following:

cmake -DZKSNARK=$ZKSNARK ..

where $ZKSNARK is PGHR13(see https://eprint.iacr.org/2013/279, http://eprint.iacr.org/2013/879) or GROTH16(see https://eprint.iacr.org/2016/260).

Terminal 2: Start an Ethereum testnet to test the smart contracts

# Start the ethereum test net by running the following commands
cd zeth-contracts

# If the install below fails with python errors, try running:
npm config set python python2.7

# Install dependencies
npm install

# Start a local Ethereum testnet
npm run testrpc

Terminal 3: Start the testing Python stub

# Configure your environment
. ./setup_env.sh

cd pyClient
# Follow the few steps described in the README of the python stub

Use the pyClient

This Proof of Concept comes with some minimal building blocks to integrate Zeth with your applications. You can use the python client to interact with the proving service and request proofs on a given (instance, witness) pair.

Secure Multi Party Computation for the Groth16 SRS generation

See MPC for SRS generation documentation

Development dependencies (for building outside of the Docker container)

Immediate dependencies are provided as submodules and compiled during the Zeth build. Ensure submodules are synced.

The following libraries are also required to build:

grpc
gmp
boost
openssl

References and useful links

BabyZoe: https://github.com/zcash-hackworks/babyzoe
Miximus: https://github.com/barryWhiteHat/miximus.git
SCIPR LAB github: https://github.com/scipr-lab/
Zcash github: https://github.com/zcash/zcash
ZeroCash: http://zerocash-project.org/
Zerocash-Ethereum: https://github.com/AntoineRondelet/zerocash-ethereum

License notices:

Zcash

Copyright (c) 2016-2018 The Zcash developers
Copyright (c) 2009-2018 The Bitcoin Core developers
Copyright (c) 2009-2018 Bitcoin Developers

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.


The MIT software license (http://www.opensource.org/licenses/mit-license.php)
above applies to the code directly included in this source distribution.
Dependencies downloaded as part of the build process may be covered by other
open-source licenses. For further details see 'contrib/debian/copyright'.


This product includes software developed by the OpenSSL Project for use in the
OpenSSL Toolkit (https://www.openssl.org/). This product includes cryptographic
software written by Eric Young (eay@cryptsoft.com).


Although almost all of the Zcash code is licensed under "permissive" open source
licenses, users and distributors should note that when built using the default
build options, Zcash depends on Oracle Berkeley DB 6.2.x, which is licensed
under the GNU Affero General Public License.

Libsnark

The libsnark library is developed by SCIPR Lab (http://scipr-lab.org)
and contributors.

Copyright (c) 2012-2014 SCIPR Lab and contributors (see AUTHORS file).

All files, with the exceptions below, are released under the MIT License:

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

Miximus

barryWhiteHat/miximus GNU General Public License v3.0

Shirikatsu/zeth