Bridges
In the TON ecosystem, bridges allow users to transfer assets and data between TON and other major blockchains like Ethereum, BNB Chain, and Polygon.
What are cross-chain bridges?
Cross-chain bridges are protocols that allow users to transfer cryptocurrencies, tokens, and sometimes arbitrary data from one blockchain to another. They act as connectors between otherwise isolated blockchain networks, enabling a multi-chain ecosystem where assets can move freely across different platforms.
Bridges typically work by locking assets on the source blockchain and minting equivalent wrapped tokens on the destination blockchain. When users want to move assets back, the wrapped tokens are burned on the destination chain, and the original assets are unlocked on the source chain.
Types of cross-chain bridges
Trustless vs. custodial bridges
Trustless bridges:
- Use smart contracts and cryptographic proofs for validation
- No single point of failure
- Decentralized verification mechanisms
Centralized bridges:
- Rely on trusted entities or multi-signature wallets
- Single point of failure risk
- Generally, they are easier to implement
Asset transfer methods
Lock-and-Mint bridges:
- Lock original assets on the source chain
- Mint wrapped tokens on the destination chain
- Most common bridge type
Burn-and-Mint bridges:
- Burn tokens on the source chain
- Mint new tokens on the destination chain
- Used for native multi-chain tokens
Bridges on TON
The TON blockchain has a bridge ecosystem that connects it to major EVM-compatible networks. There are several kinds of bridge providers on TON.
Legacy: official TON bridges
During the TON ecosystem's early development, a few official bridges had protocol-level support from 2021 to 2023. These bridges are now deprecated.
Any attempt to use them will result in a loss of funds.
Outbound bridges (config parameters 71-73)
These bridges wrap Gram into other networks:
- ETH-TON Bridge: config parameter 71
- BNB-TON Bridge: config parameter 72
- Polygon-TON Bridge: config parameter 73
Inbound bridges (config parameters 79, 81-82)
These bridges wrap tokens from other networks into Gram:
- ETH-TON Bridge: config parameter 79
- BNB-TON Bridge: config parameter 81
- Polygon-TON Bridge: config parameter 82
Third-party bridge ecosystem
The TON ecosystem features multiple bridge providers offering different features and supported networks. Look up statistics for existing bridges on the Bridge Dashboard.