# BTC Bridge

The BTC Bridge in the MARA ecosystem serves as the secure conduit for the transfer of BTC Tokens between the Bitcoin Network and EVM Chains, including MARA. This bridge is integral to the functionality and security of the MARA network, playing a crucial role in the seamless integration and movement of assets.

### Key Functionality of the BTC Bridge: <a href="#key-functionality-of-the-btc-bridge" id="key-functionality-of-the-btc-bridge"></a>

#### **Token Bridging and Uniform Mapping** <a href="#token-bridging-and-uniform-mapping" id="token-bridging-and-uniform-mapping"></a>

The primary function of the BTC Bridge is to facilitate the transfer of BTC Tokens from the native Bitcoin Chain and various EVM-compatible Chains into the MARA ecosystem. Once transferred, these tokens are uniformly mapped and represented as BBTC within MARA, ensuring consistency and ease of use across the platform.

#### Enhanced Security Measures <a href="#enhanced-security-measures" id="enhanced-security-measures"></a>

* ***Beyond Multi-Signature Contracts***: Unlike conventional bridge mechanisms that rely on multi-signature contracts often controlled by a limited group of team addresses, MARA’s BTC Bridge introduces a more robust security framework. This design significantly mitigates the risks associated with the concentration of control in multi-signature models.
* ***Validator-Centric Security***: Network validators bear the responsibility of safeguarding the bridge’s security. Each Validator operates a dedicated Bridge Node, contributing to the signing of cross-chain messages and ensuring that the bridge’s security is aligned with overall security.

#### Consensus and Validation Process <a href="#consensus-and-validation-process" id="consensus-and-validation-process"></a>

* ***Shared Security and Consensus***: Drawing inspiration from models like Restaking’s Shared Security, the MARA BTC Bridge implements a system where Validators collectively maintain and secure the bridge. This collaborative approach distributes the responsibility of security, enhancing the reliability of cross-chain transactions.
* ***Majority Approval for Transactions***: For any cross-chain transaction to be validated and executed, it requires approval from over 50% of the Validators. This consensus mechanism ensures that every transaction is thoroughly vetted and endorsed by a majority of the network’s validators, adding an extra layer of security and trust to the bridging process.
