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Getting Started with Chain Signatures

Chain Signatures allows all NEAR accounts - including smart contracts - to sign transactions for other blockchains (such as Bitcoin, Ethereum or Solana).

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This innovation leverages Multi-Party Computation (MPC) and a distributed network of node operators to create joint signatures from arbitrary payloads, allowing NEAR accounts to control external blockchain accounts.

Derive addresses on any blockchain, build DeFi on Bitcoin, create multi-chain apps with one contract, or enable account abstraction across all chains - all without the need for traditional bridges or wrapped tokens

Chain Signatures vs. Traditional Bridges​

FeatureChain SignaturesTraditional Bridges
Security ModelDecentralized MPC nodesTrusted validators or relayers
Asset TypeNative tokens (real BTC, ETH)Wrapped tokens (wBTC, wETH)
Smart Contract SupportYes, contracts can sign transactionsUsually user-only
Chains SupportedAny blockchainSpecific pairs only
Bridge RiskNo locked funds, no bridge exploitsBillions locked, frequent hacks
UXSeamless, single accountMultiple wallets needed

How does it work?​

When a NEAR account - could be a user or a smart contract - wants to interact with a foreign blockchain, it just need to follow four simple steps.

Chain Signatures Chain signatures flow

1. Deriving Foreign Addresses​

Chain Signatures uses derivation paths to represent accounts on foreign blockchains

The NEAR account’s name and the derivation path are used to mathematically derive a unique address for the user on the foreign blockchain

Derivation Paths

A NEAR account will always derive the same address on the foreign blockchain using the same derivation path

Notice that, since the foreign address is derived from the NEAR account name, it is not possible for another NEAR account to control the same address

2. Creating the Transaction​

The client constructs the foreign transaction to be signed, which varies depending on the target blockchain

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You can use the Omni Transaction Rust library to build transactions easily for different blockchains (like Bitcoin and Ethereum) inside NEAR contracts and Rust clients.

3. Requesting the Signature​

A NEAR account or contract calls the sign method of the MPC smart contract (v1.signer) to sign the transaction and waits while our MPC service generates the signature

4. Relaying the Signature​

Once the signature is ready, the client reconstructs the signed transaction using the signature and broadcasts it to the destination blockchain

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Using Chain Signatures, developers can build cross-chain DeFi applications with seamless user experiences, eliminating the need for traditional bridges. This process eliminates the need for traditional bridges and enables developers to build innovative cross-chain DeFi applications with seamless user experiences.

Use Cases​

Chain Signatures can be used to build a wide range of applications that leverage blockchain interoperability. Here are some examples:

  1. DeFi on Bitcoin (and other chain without smart contracts)
    • Chain signatures allow NEAR smart contract to program assets on Bitcoin
    • Build lending, swaps, runes launchpads, passkey-based Bitcoin wallets, and more
  2. Chain agnostic applications
    • Since chain signatures can sign transactions for all blockchains, developers can support every single chain with just one smart contract
    • Multichain DEXs, lending protocols, oracles, derivatives, and more
  3. Multichain account abstraction
    • Users can control assets on all chains with just their NEAR account, and can utilize account abstraction features on any chain including passkeys, key rotation, etc
    • Using the multichain gas relayer, users can pay for gas fees on any chain using USDC
  4. Privacy
    • Chain signatures can be used to encrypt and decrypt information in a programmatic way
    • This enables privacy applications, and even decrypting information based on ownership of assets/NFTs

How to Get Started?​

  1. Familiarize Yourself with Chain Signatures:
  2. Explore the Use Cases:
  3. Access Resources and Documentation:
  4. Try the Demos:
  5. Engage with the Community:

Common Questions​

What blockchains are supported?​

Bitcoin, Ethereum, Dogecoin, Ripple, Cosmos chains, and any blockchain that supports ECDSA or EdDSA signatures. More chains are continuously being added.

Do I need to lock tokens in a bridge?​

No. Chain Signatures directly control native assets on the target blockchain. No wrapped tokens, no bridge risk.

Can smart contracts use Chain Signatures?​

Yes! NEAR smart contracts can sign transactions for other blockchains, enabling programmable cross-chain applications.

How secure is the MPC system?​

The MPC network is decentralized across multiple node operators. No single node has access to the full private key. Requires threshold consensus to sign.

What's the difference from account abstraction?​

Chain Signatures enables account abstraction across all chains. Your NEAR account (with passkeys, 2FA, etc.) can now control assets on Bitcoin, Ethereum, and more.

How much does it cost?​

You can sign transactions on NEAR for free, but the external account will still need tokens to pay for gas fees in the target blockchain.

Where to Learn More?​

To dive deeper into Chain Signatures and its applications, you can explore the following resources:

  • Community and Support: Engage with the NEAR community on social media platforms like Twitter and participate in discussions to stay updated on the latest developments