Ren Bridge.

A Ren Bridge is the gateway that lets native Bitcoin enter Ethereum DeFi as renBTC, a token minted 1:1 against BTC held by the RenVM network. Rather than routing your coins through a single custodian, RenVM splits custody across a decentralized set of nodes called darknodes, each holding only a fragment of the key material needed to move the underlying Bitcoin. When you send BTC to a deposit address the protocol generates, the darknode network watches the Bitcoin blockchain, waits for the required confirmations, and mints the matching amount of renBTC to your Ethereum address. Burning renBTC reverses the flow and releases native Bitcoin back to an address you control. The result works like a bridge run by a distributed group of operators instead of one company holding a vault.

Darknodes and threshold signatures

Each darknode stores only a share of the private key controlling a given pool of deposited Bitcoin, generated through multi-party computation. No single operator ever holds a complete key, so moving funds requires a threshold of darknodes to cooperate and sign together. This split-custody design is what separates RenVM from a bridge where one exchange or company controls the Bitcoin outright.

renBTC as a standard Ethereum token

Once minted, renBTC behaves like any other ERC-20 token on Ethereum: it shows up in a normal wallet, trades on decentralized exchanges, and can be supplied to lending markets or liquidity pools built for ERC-20 assets. Its only special property is the 1:1 backing and the burn mechanism that lets it convert back to native Bitcoin on demand.

Moving Bitcoin through RenVM runs in two directions, and each one triggers a different network action.

Minting: Bitcoin in, renBTC out

To mint, you send BTC to a deposit address the protocol derives for your session. The darknode network monitors that address, and once your Bitcoin transaction reaches enough confirmations — typically six, matching Bitcoin's own security assumptions — the network signs a mint instruction and renBTC appears in your Ethereum wallet. Nothing is minted before the Bitcoin side has settled; the wait exists specifically to avoid crediting a deposit that could still be reorganized out of the chain.

Burning: returning to native Bitcoin

Burning works the other way. You submit a transaction that destroys your renBTC on Ethereum and specifies the Bitcoin address that should receive the funds. The darknode network verifies the burn, signs a release transaction on the Bitcoin network, and native BTC lands at the address you named. Because the darknodes hold only key shares, this release step still requires the same cooperating threshold of nodes as a mint.

Costs on this route come from three places: the Bitcoin network fee to send your deposit, Ethereum gas to receive or spend renBTC, and a small RenVM protocol fee taken from the minted or released amount. Timing is asymmetric in the same way confirmations are — a mint waits on Bitcoin's block time, while a burn is often faster once it clears Ethereum.

Step	What you pay	Typical time
Mint (BTC to renBTC)	Bitcoin network fee + RenVM mint fee	~60 minutes for confirmations
Ethereum activity	Ethereum gas (ETH)	Seconds to minutes
Burn (renBTC to BTC)	RenVM burn fee + Bitcoin release fee	~10–30 minutes

Moving Bitcoin into Ethereum DeFi through RenVM follows the same sequence every time.

• Generate a deposit address for your session and send BTC to it from a wallet you control.
• Track the deposit on a block explorer such as mempool.space while it accumulates confirmations.
• Wait for the darknode network to reach the confirmation threshold and sign the mint instruction.
• Receive renBTC in your Ethereum wallet and use it across lending, trading or liquidity pools.
• When you want native Bitcoin back, burn renBTC and name the Bitcoin address that should receive the release.

RenVM does not hold your coins in a single company's custody, but self-custodial does not mean risk-free.

What distributed custody protects against

Splitting key shares across many darknodes means no single operator, exchange or employee can unilaterally move the Bitcoin backing renBTC. An attacker would need to compromise a threshold of independently run nodes at once, which is a materially harder target than breaching one custodian's hot wallet.

Risks that remain

The smart contracts that mint and burn renBTC on Ethereum are still software, and the darknode network's signing logic is still code that can contain bugs. Check the destination address before you sign, confirm the amount that actually minted against what you sent, and avoid granting token approvals you do not plan to use again.

Native Bitcoin cannot interact with Ethereum contracts on its own, so every route that brings BTC into DeFi relies on some wrapped representation. RenVM's renBTC and a custodial token like WBTC solve the same problem with different trust models: WBTC is minted by a small set of licensed custodians who hold the underlying Bitcoin directly, while renBTC's backing sits with the distributed darknode network instead of one company. Neither model removes trust entirely — you are trusting either a custodian's solvency and compliance or a threshold of independent node operators — but the two spread that trust differently. Checking a token's total value locked and mint history on a tracker like DefiLlama is a reasonable way to see how much the market currently relies on each route.

Why some users still pick a custodial wrapper

A custodial token can sometimes mint and redeem faster because a single custodian is making the decision rather than coordinating a threshold of independent nodes. That speed comes at the cost of concentrating trust in one organization's solvency, legal standing and internal controls, which is exactly the single point of failure a distributed darknode network is designed to avoid.

Checking which route the market actually uses

Total value locked in renBTC relative to other wrapped Bitcoin tokens gives a rough read on how much capital currently trusts each design. That figure moves over time as liquidity shifts between custodial and decentralized routes, so it is worth checking current numbers rather than relying on a snapshot from when a project first launched.

Once renBTC sits in your wallet, it works like any Bitcoin-pegged asset across Ethereum DeFi. It can be supplied to lending markets to earn yield, paired against ETH or stablecoins in liquidity pools, or used as collateral the way you would use any ERC-20 token. Because renBTC's value tracks Bitcoin rather than Ethereum, it also gives DeFi strategies a way to hold BTC price exposure without ever leaving the Ethereum ecosystem. Burning back to native Bitcoin through RenVM remains available at any point, so holding renBTC is a choice you can reverse rather than a one-way conversion. Holding renBTC alongside native ETH also means only one gas token to manage for everyday Ethereum activity, since the Bitcoin side of the position no longer needs its own network fees until you decide to burn back out.