What are Chain Signatures?

Chain signatures enable NEAR accounts, including smart contracts, to sign and execute transactions across many blockchain protocols.

This unlocks the next level of blockchain interoperability by giving ownership of diverse assets, cross-chain accounts, and data to every single NEAR account.

Diagram of a chain signature in NEAR

• To get started using Chain Signatures in your project see Create a Chain Signature.
• This technology is currently in alpha and should only be used in a testnet environment.

How It Works

Controlling accounts and their assets on other blockchain platforms is made possible thanks to the interaction between three elements:

1. Derivation Paths - A deterministic way to derive foreign addresses from one NEAR account
2. Multichain Smart Contract - Receives requests to sign a transaction for other blockchains
3. Multiparty Computation Service Third-party service providing signatures to the contract

Derivation Paths: One Account, Multiple Chains

Chain Signatures link NEAR accounts to addresses in other blockchain using Additive Key Derivation (a simple mechanism for deriving many subkeys from a single master key). These keys are generated using derivation paths (or paths for short).

A derivation path is simply a string (e.g. ethereum-1, ethereum-2, etc) that in conjunction with the NEAR account derives a unique address on the target blockchain.

For example, we can derive multiple Ethereum addresses from example.near by using different paths:

1. example.near + ethereum-1 = 0x1b48b83a308ea4beb845db088180dc3389f8aa3b