Zecale (/zi:kale/)

A general purpose zk-SNARK aggregator leveraging recursive composition of SNARKs.

This project can be used to:

1. Scale privacy preserving solutions like Zeth by aggregating proofs off-chain (i.e. generate a proof of computational integrity of their validity) and settling a batch of transactions via a single transaction on-chain. This is also referred to as "zk-zk-rollups".
2. Wrap proofs for a given statement in order to hide the predicate that was evaluated. In other words, by setting the size of the batch to 1, a "wrapping" proof is generated to prove the correct verification of another proof on witness the verification key and the public inputs. The wrapping proof can the be settled on-chain. This use is very similar to the "Zero-knowledge EXEcution environment" described in Zexe.

🚨 WARNING This project is a Work In Progress (WIP). It is highly inefficient and has not been thoroughly reviewed. Please do not use in production!

Building and running the aggregator-server:

💻 Warning This project primarily targets x86_64 Linux and macOS platforms.

Environment

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

• Docker
• Python3 (at least version 3.7)

Additionally, several tools from the GCC and LLVM tools suite are used to improve code quality and generate the documentation of the project. If these are installed they can be executed by passing options to the build:

• Doxygen
• clang-format
• clang-tidy
• cppcheck
• include-what-you-use
• llvm-symbolizer

Build and run on host machine

Dependencies

Immediate dependencies are provided as submodules and compiled during the build. The following libraries are also required to build:

• grpc
• gmp
• boost

Build and run

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

# Initialize the submodules
git submodule update --init --recursive

# Configure your environment
. ./setup_env.sh

# Compile the aggregator
mkdir build
cd build
cmake ..

# Compile all targets
make

# (optional) Build and run the all tests (unit tests, syntax checks, etc)
make check
# Alternatively, run: make build_tests && make test

# Start the aggregator-server process
aggregator-server

Build and run in a docker container

# Pull the zeth-base image (this project has the same configuration as Zeth)
docker pull ghcr.io/clearmatics/zeth:latest-base
# To fetch a specific version of the zeth-base image, replace `latest` by
# the desired version number (e.g. `zeth:0.0.2-base`)

# Build the Zecale dev image
docker build -f Dockerfile-zecale -t clearmatics/zecale-dev:0.5 .

# Start the container
docker run -ti -p 50052:50052 --name zecale clearmatics/zecale-dev:0.5

Generate the Doxygen documentation

To generate the documentation of Zecale:

cd build
cmake .. -DGEN_DOC=ON && make docs

Compile the project using 'sanitizers'

You can select the sanitizer of your choice (one of the sanitizers listed here) by passing the flag -DSANITIZER=<sanitizer> to cmake.

Example:

cd build
cmake -DCMAKE_C_COMPILER=/usr/bin/clang -DCMAKE_CXX_COMPILER=/usr/bin/clang++ -DSANITIZER=Address -DCMAKE_BUILD_TYPE=Debug ..
make check

Run analysis tools on the code

Several tools can be ran on the code. These can be enabled via a set of compilation options.

Note: The clang-tidy target runs a clang-tidy python script that should be fetched from here. To do so, run: cd build && wget https://raw.githubusercontent.com/llvm/llvm-project/master/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py

Example:

# run-clang-tidy.py needs to be in the PATH to be found
PATH=$PATH:${PWD}
chmod +x run-clang-tidy.py

cmake -DUSE_CLANG_FORMAT=ON -DUSE_CPP_CHECK=ON -DUSE_CLANG_TIDY=ON ..
make cppcheck
make clang-format
make clang-tidy

Build and run the client

See the client README for instructions.

License notices:

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.