Axelar Open-Sources Multi-Party Cryptography Libraries

Axelar is pleased to announce the release of the source code for two Rust-language crates for multi-party cryptography under a permissive and conventional dual Apache2/MIT license. The newly released crates are called tofn and tofnd. They provide implementations for multi-party cryptography protocols used in the Axelar network.

The Axelar network runs various multi-party protocols to process cross-chain requests. Multi-party protocols are critical in building decentralized interoperability protocols across blockchains. They enable a group of validators to reach collective decisions on which transactions should be processed. Multi-party key-generation and signing are two of the core primitives needed to process such requests. These primitives can be achieved by several methods, including:

• Basic multi-signatures (where appropriate), and
• Cryptographic threshold protocols (to save on gas costs or translation sizes).

At present, Axelar utilizes both these methods via tofn and tofnd with more to come in the future.

tofn

tofn (t-of-n) is a pure-Rust library that provides:

• An implementation of the GG20 protocol for threshold-ECDSA.
• Exposure to the ECDSA primitives needed for basic multi-signatures.
• A general-purpose SDK (software development kit) to facilitate the development and use of multi-party cryptography protocols such as GG20.

Learn more at the tofn git repository.

tofnd

tofnd (tofn-daemon) is a pure-Rust executable that provides:

• A gRPC server that exposes the multi-party cryptography functionality of the tofn library.
• Encrypted storage of cryptographic secret keys.

Learn more at the tofnd git repository.

The road ahead

Both tofn and tofnd are currently under active and ongoing development. Both repos were audited by NCC Group Cryptography Services on 2021-aug-10 and by Adrian Hamelink and Lúcás Meier on 2021-oct-29. Open-sourcing these libraries is an important milestone for the Axelar ecosystem and community. Our core mission is to build a secure and robust cross-chain interoperability network, and we always welcome contributions and feedback from the community.