RenBridge had two routes, but both stopped working in 2022. For a current Bitcoin transfer, use the separate service at RenBridge to bridge or swap crypto across chains in one flow. The original routes created a Bitcoin-backed token on another chain, then destroyed that token to release Bitcoin.
What Is the RenBridge Crypto Bridge?
It was a cross-chain bridge, a service that carried Bitcoin’s value to another blockchain. Its Bitcoin token was renBTC, a wrapped token backed by Bitcoin (BTC) held for redemption. Holding renBTC on Ethereum was different from holding BTC in a Bitcoin wallet.
To mint renBTC, or create it, a user sent BTC to a Bitcoin deposit address. The bridge waited for six confirmations, meaning six new blocks after the payment. That usually took about an hour; the user then approved an Ethereum transaction to receive renBTC.
To return, the user burned renBTC on Ethereum, permanently removing those tokens. The bridge then released BTC to a Bitcoin address. The move involved Bitcoin transaction fees, Ethereum gas (the cost of an Ethereum transaction), and bridge fees.
The Two Historical Routes
The two routes served opposite needs: minting brought Bitcoin’s value to Ethereum, while burning returned native BTC to Bitcoin.
- Mint BTC into renBTC. This suited someone who wanted to use Bitcoin’s value in an Ethereum app. It did not suit someone who needed spendable BTC on Bitcoin, because the result was an Ethereum token.
- Burn renBTC for BTC. This suited someone who wanted to leave Ethereum with Bitcoin in a Bitcoin wallet. It did not suit someone seeking ETH, Ethereum’s own coin: burning released BTC, not a coin of the user’s choice.
These were directions within one discontinued bridge, not two services available today. An old tutorial may still show a deposit address, but it cannot create a new renBTC mint. Do not send BTC to an address copied from those instructions.
What Are the RenBridge Alternatives for Bridging Bitcoin?
The useful distinction is what you need to receive: a Bitcoin-backed token, another coin, or native BTC. Check both the destination blockchain and the exact asset before choosing a route.
- Custodial wrapped Bitcoin. An issuer holds BTC and issues a matching token on another chain. This fits an Ethereum app that accepts that token. It does not fit if you need native BTC or do not want to rely on the issuer to honor redemption.
- Group-backed wrapped Bitcoin. A group of signers controls the BTC backing a token instead of one issuer. This fits an app that accepts its specific token. It does not fit if the app accepts a different Bitcoin token; wrapped tokens are not automatically interchangeable.
- Cross-chain swap. Available coins on each chain fund an exchange from BTC into the asset you request. This fits a move that should end in ETH rather than a Bitcoin-backed token. It does not fit if you need a particular wrapped Bitcoin token for an app.
Say you have 0.01 BTC and want ETH on Ethereum. Select BTC on Bitcoin as the asset you send, then ETH on Ethereum as the asset you receive. A route that delivers wrapped Bitcoin leaves you with a different result, even though its value follows Bitcoin.
Compare the amount you will receive before sending. The difference can reflect Bitcoin fees, Ethereum gas, service charges, and slippage, which means a change in the swap price. For example, a 0.5% charge on 0.01 BTC equals 0.00005 BTC before other costs.
If you already hold renBTC, check whether a current swap accepts that exact token. A renBTC wallet balance is not native BTC, and the old burn route no longer provides redemption. Check the quoted output before treating it as a way back to Bitcoin.