Avalanche Bridge is the canonical bridge to move assets to and from Avalanche's C-Chain. Assets are locked on the source chain and minted on the Avalanche network.

Bridge

Avalanche Bridge

Protocol Code Quality

Protocol Maturity

Protocol Design

Risk Rating

Watch Out

* [Documentation](https://support.avax.network/en/articles/6092559-avalanche-bridge-ab-faq) 
 * Auditors 
 	* [Halborn](https://github.com/ava-labs/audits/blob/main/bridge/Avalanche_Bridge_Security_Audit_Report_Halborn_v1_1.pdf) 
 * Please see our [FAQ on experienced auditors](https://help.exponential.fi/en/articles/6381015-what-are-experienced-auditors)

Exploit/Hacks

Unknown

* [Website](https://bridge.avax.network/)  
 * Token: AVAX  
 * Tags: Bridge

Info

Key Metrics

Information


- Code reviewed by at least one experienced auditor; [Halborn](https://github.com/ava-labs/audits/blob/main/bridge/Avalanche_Bridge_Security_Audit_Report_Halborn_v1_1.pdf) audited in June 2021
- Public team promotes accountability
- No documented protocol hacks since launch

green


- Core protocol launched in 2021; maturity over 1 year reduces technical risk as smart contracts are moderately battle-tested
- Top 1% by total value locked reduces risk
- Centralized governance increases risk
- Low voting power concentration reduces risk


- No concerns identified
- Externally verified bridge system that is reliant on an external set of validators who don't have to post any collateral; users essentially have to put their trust on the reputation that all validators will act honestly
- The Avalanche Bridge is managed by the Avalanche chain team, which increases how much oversight the bridge receives as it is key to the well-functioning of the Avalanche chain

Risk Assessment

The Avalanche native bridge can be used to easily transfer ERC-20 tokens from Ethereum to Avalanche's C-Chain, while also receiving a small AVAX airdrop for bridging assets over $75.

What we like

The bridge relies on external, trusted validators which require greater trust assumptions from the user around its security.

What we like less

Offers you a simple way to transfer your crypto assets from Ethereum to Avalanche to access decentralized applications with lower gas fees and faster transaction speeds.

What it means for you

Summary

#### How do you pay for transaction fees on Avalanche?
The Avalanche bridge is a two-way token bridge that allows seamless transfers between the Avalanche C-Chain and Ethereum. Users who wish to use ERC-20 assets within the Avalanche network must first lock their assets in the ChainBridge contract, after which an equivalent token will be minted on Avalanche and sent to the specified user address.
#### What are the role of bridge nodes?
The Avalanche bridge can be broken down into two main parts: the SGX application and a group of third-party indexers and verifiers called "bridge nodes". The nodes are responsible for indexing the Avalanche and Ethereum networks and submitting eligible transactions to the enclave for processing. The Intel SGX application consists of a trusted codebase that runs within an enclave and an untrusted codebase that runs outside. The SGX application requires 6 of 8 nodes to submit the same transaction before generating the signed transaction to process the transfer on the destination chain. The current group of trusted bridge nodes include Ankr, Blockdaemon, Chainstack, Protofire, Avascan, Ava Labs, Bware Labs and Halborn.
#### How secure is the Avalanche bridge?
The Avalanche bridge is secured by Intel SGX technology. This technology restricts how transfers are performed and nobody (including system administrators) has access to the keys that control the funds. All bridge transfers must be signed by 6 of 8 third-party nodes that also secure and backup an encrypted piece of the bridge's key to enable reconstitution in the event of a hardware failure. Bridge nodes are security tested on a quarterly basis to ensure adherence to strict security standards.