# Bridge and Cross-Chain Transfers

Trustless interoperability between Verus and Ethereum via the Verus-Ethereum bridge

The Verus-Ethereum bridge is a trustless, decentralized protocol that enables transfers of value between the Verus and Ethereum blockchains. Unlike centralized bridges that rely on custodians holding funds, the Verus bridge uses notarization proofs validated by both chains — the same consensus mechanism that secures Verus itself.

The bridge allows you to:

• Send ETH and ERC-20 tokens (DAI, MKR) from Ethereum to Verus
• Send VRSC and Verus-side tokens from Verus back to Ethereum
• Convert between bridged assets using Verus's protocol-level AMM
• Move VerusIDs and currency definitions cross-chain

┌─────────────────────────────────────────────────────────────┐
│                                                             │
│   ETHEREUM                          VERUS                   │
│                                                             │
│   ETH ─────────────────────────→  vETH                     │
│   DAI ─────────────────────────→  DAI.vETH                 │
│   MKR ─────────────────────────→  MKR.vETH                 │
│                                                             │
│   ←─── Bridge.vETH (basket currency) ───→                  │
│                                                             │
│   VRSC token ←─────────────────  VRSC                      │
│                                                             │
└─────────────────────────────────────────────────────────────┘

Bridge.vETH is a basket currency that sits at the heart of the bridge. It holds reserves of multiple currencies from both chains:

• VRSC — Native Verus currency
• vETH — Ethereum (ETH) represented on Verus
• DAI.vETH — DAI stablecoin represented on Verus
• MKR.vETH — MakerDAO governance token represented on Verus

Because Bridge.vETH is a basket, it functions as an automatic exchange. You can convert between any of its reserve currencies using the same AMM mechanism described in Basket Currencies and DeFi.

When an Ethereum asset crosses the bridge, it gets a mapped representation on Verus:

Note: Additional ERC-20 tokens can be mapped to the bridge. The list above includes the currently active mapped tokens. Check the bridge interface at eth.verusbridge.io for the latest available tokens.

The .vETH suffix indicates the token originated from the Ethereum side of the bridge. These mapped tokens are fully fungible on Verus — you can hold them, trade them, use them in basket currencies, or bridge them back to Ethereum at any time.

Every currency on Verus has a permanent i-address identifier:

Every cross-chain transfer follows a three-phase process: export → notarization → import.

When you initiate a cross-chain transfer, the source chain creates an export transaction. This locks or burns the source currency and records the transfer details (destination, amount, fees) in a special output.

# Example: Send 10 VRSC to Ethereum
verus sendcurrency '*' '[{
  "address": "0xYourEthAddress",
  "amount": 10,
  "currency": "VRSC",
  "exportto": "vETH",
  "feecurrency": "veth"
}]'

The export is bundled with other exports in the same block into an export bundle — a batch of transfers that cross together.

Notaries are nodes that run both a Verus node and an Ethereum node. They observe finalized transactions on one chain and create notarization proofs for the other chain.

Source Chain                    Notaries                    Dest Chain
     │                            │                            │
     │  1. Export tx confirmed    │                            │
     │ ─────────────────────────→ │                            │
     │                            │  2. Create proof           │
     │                            │  3. Submit notarization    │
     │                            │ ─────────────────────────→ │
     │                            │                            │
     │                            │  4. Dest chain validates   │
     │                            │     proof against headers  │

Key properties of notarization:

• Multiple notaries must agree — no single point of failure
• Notarizations include Merkle proofs of the export transactions
• The destination chain independently validates the proofs
• Notaries cannot forge transfers — they can only attest to what actually happened

Once a valid notarization is accepted by the destination chain, the import is processed automatically. The destination chain mints or releases the appropriate currency to the recipient address.

For Ethereum-bound transfers, the import is processed by the Delegator smart contract on Ethereum. For Verus-bound transfers, the Verus blockchain processes the import natively.

ETH → VRSC Transfer:

  Ethereum                                              Verus
  ────────                                              ─────
  1. User sends ETH to              
     Delegator contract          
     with Verus destination      
           │                     
           │ (ETH locked)        
           ▼                     
  2. Export recorded on          
     Ethereum                    
           │                     
           │ (~15 min finality)  
           ▼                     
  3. Notaries observe ──────────────→ 4. Notarization proof
     finalized export                    submitted to Verus
                                              │
                                              ▼
                                  5. Verus validates proof
                                     against ETH headers
                                              │
                                              ▼
                                  6. Import processed:
                                     vETH minted to
                                     destination address
                                              │
                                              ▼
                                  7. User receives vETH
                                     (or auto-converts
                                      to VRSC via basket)

When bridging from Ethereum to Verus, fees are paid in ETH. When bridging from Verus to Ethereum, if you don't set the feecurrency flag, VRSC is automatically converted to vETH via the Bridge.vETH basket to cover Ethereum gas costs. You can explicitly set "feecurrency": "veth" to pay fees in vETH directly.

Verus-to-Ethereum transfers take a similar amount of time. Expect roughly 1 hour for a complete bridge transfer in either direction, depending on network conditions.

The bridge's security rests on several layers:

Transfers are not trusted — they are proven. Each notarization includes cryptographic Merkle proofs that the destination chain verifies independently. A notary cannot claim a transfer happened if it didn't, because the proof wouldn't validate against the source chain's block headers.

Multiple independent notaries must agree on the state of the source chain. No single notary can authorize an import. This is similar to how multi-signature wallets require multiple keys — except here the "signatures" are notarization proofs from independent observers.

Unlike wrapped-token bridges (e.g., WBTC), where a custodian holds the underlying asset, the Verus bridge locks assets in smart contracts (Ethereum side) or burns/mints them at the protocol level (Verus side). No entity holds custody of bridged funds.

The Ethereum side of the bridge uses a Delegator contract pattern. The contract:

• Validates notarization proofs from Verus
• Processes imports (releasing ETH/tokens to recipients)
• Processes exports (locking ETH/tokens for bridge transfers)
• Is upgradeable through Verus notarization consensus, not a single admin key

The bridge waits for sufficient confirmations (finality) on both chains before processing transfers. This protects against blockchain reorganizations that could invalidate transfers.

The simplest way to bridge is via the web interface:

1. Go to eth.verusbridge.io
2. Connect your Ethereum wallet (MetaMask, etc.)
3. Select the token to bridge (ETH, DAI, MKR)
4. Enter your Verus destination (R-address or VerusID)
5. Enter the amount
6. Confirm the transaction
7. Wait ~30-60 minutes for the transfer to complete

Use sendcurrency with exportto:

# Send VRSC to Ethereum
verus sendcurrency '*' '[{
  "address": "0xYourEthAddress",
  "amount": 10,
  "currency": "VRSC",
  "exportto": "vETH",
  "feecurrency": "veth",
  "refundto": "YourVerusRAddress"
}]'

# Send vETH back to Ethereum as ETH
verus sendcurrency '*' '[{
  "address": "0xYourEthAddress",
  "amount": 0.5,
  "currency": "vETH",
  "exportto": "vETH",
  "feecurrency": "veth",
  "refundto": "YourVerusRAddress"
}]'

You can bridge and convert simultaneously. For example, bridge ETH to Verus and receive VRSC (not vETH):

From the Verus side, if you hold vETH:

# Convert vETH → VRSC through Bridge.vETH basket
verus sendcurrency '*' '[{
  "address": "myidentity@",
  "amount": 0.5,
  "currency": "vETH",
  "convertto": "VRSC",
  "via": "Bridge.vETH"
}]'

# View Bridge.vETH currency details and reserves
verus getcurrency "Bridge.vETH"

# Check pending exports
verus getexports "Bridge.vETH"

# Check pending imports
verus getimports "Bridge.vETH"

1. Trustless — The bridge uses cryptographic proofs, not custodians. Notaries attest to what happened; the destination chain verifies independently.
2. Bidirectional — Assets flow both ways: Ethereum → Verus and Verus → Ethereum.
3. Integrated AMM — Bridge.vETH is a basket currency, so bridged assets can be converted instantly via the protocol-level AMM.
4. Multi-asset — ETH, DAI, MKR, and VRSC are all supported. Additional ERC-20 tokens can be added through governance.
5. Protocol-level — The bridge is not a third-party dApp. It's part of the Verus protocol, secured by the same consensus mechanism as the blockchain itself.
6. ~30-60 minutes — Transfers take time because both chains must reach finality. This is a security feature, not a limitation.

• Basket Currencies and DeFi — How the Bridge.vETH basket works
• How To: Bridge from Ethereum — Step-by-step bridging guide
• How To: Convert Currencies — Converting bridged assets
• sendcurrency — The command that does it all
• getcurrency — Check bridge reserves and status

As of Verus v1.2.x.