Multi-party ECDSA
This project is a Rust implementation of {t,n}-threshold ECDSA (elliptic curve digital signature algorithm).
Threshold ECDSA includes two protocols:
- Key Generation for creating secret shares.
 - Signing for using the secret shares to generate a signature.
 
ECDSA is used extensively for crypto-currencies such as Bitcoin, Ethereum (secp256k1 curve), NEO (NIST P-256 curve) and much more.
This library can be used to create MultiSig and ThresholdSig crypto wallet.
Project Status
- 
The library supports 2P-ECDSA based on Lindell's crypto 2017 paper [1]. Project Gotham-city is a proof of concept for a full two-party Bitcoin wallet that uses this library. See benchmarks and white paper there.
 - 
The library supports Gennaro and Goldfeder CCS 2018 protocol [2] for {t,n}-threshold ECDSA.
 - 
The library supports 2P-ECDSA based on Castagnos et. al. crypto 2019 paper [3]. To Enable build with
--features=cclst. 
Run Demo
The following steps are for setup, key generation with n parties and signing with t+1 parties.
Setup
- 
We use shared state machine architecture (see white city). The parameters
partiesandthresholdcan be configured by changing the file:param. a keygen will run withpartiesparties and signing will run with any subset ofthreshold + 1parties.paramfile should be located in the same path of the client softwares. - 
Install Rust. Run
cargo build --release --examples(it will build into/target/release/examples/) - 
Run the shared state machine:
./sm_manager. Currently configured to be in127.0.0.1:8001, this can be changed inRocket.tomlfile. TheRocket.tomlfile should be in the same folder you runsm_managerfrom. 
KeyGen
run gg18_keygen_client as follows: ./gg18_keygen_client http://127.0.0.1:8001 keys.store. Replace IP and port with the ones configured in setup. Once n parties join the application will run till finish. At the end each party will get a local keys file keys.store (change filename in command line). This contain secret and public data of the party after keygen. The file therefore should remain private.
Sign
Run ./gg18_sign_client. The application should be in the same folder as the keys.store file (or custom filename generated in keygen). the application takes three arguments: IP:port as in keygen, filename and message to be signed: ./gg18_sign_client http://127.0.0.1:8001 keys.store "KZen Networks". The same message should be used by all signers. Once t+1 parties join the protocol will run and will output to screen signatue (R,s).
Full demo
Run ./run.sh (located in /demo folder) in the same folder as the excutables (usually /target/release/examples. Move params file to the same folder). It will spawn a shared state machine, clients in the number of parties and signing requests for the threshold + 1 first parties.
sm_manager rocket server runs in production mode by default. You may modify the ./run.sh to config it to run in different environments. For example, to run rocket server in development:
ROCKET_ENV=development ./target/release/examples/sm_manager
```, !["Multiparty ECDSA Demo"][demo], :------------------------------------------------:, _A 5 parties setup with 3 signers (threshold = 2)_, [demo]: https://raw.githubusercontent.com/KZen-networks/multi-party-ecdsa/master/demo/MP-ECDSA%20demo.gif
## Contributions & Development Process
The contribution workflow is described in [CONTRIBUTING.md](CONTRIBUTING.md), in addition **the [Rust utilities wiki](https://github.com/KZen-networks/rust-utils/wiki) contains information on workflow and environment set-up**.
## License
Multi-party ECDSA is released under the terms of the GPL-3.0 license. See [LICENSE](LICENSE) for more information.
## Contact
Feel free to [reach out](mailto:github@kzencorp.com) or join the KZen Research [Telegram](https://t.me/kzen_research) for discussions on code and research.
## References
[1] <https://eprint.iacr.org/2017/552.pdf>
[2] <https://eprint.iacr.org/2019/114.pdf>
[3] <https://eprint.iacr.org/2019/503.pdf>