Token Bridging Models

SupraNova picks a bridging model per asset, based on where that asset originates. Every model preserves the same invariant: the representation in circulation on the destination chain can never exceed the collateral held on the source chain.

Ethereum to Supra: Lock-Mint

SupraNova’s Ethereum to Supra bridging uses the Lock-Mint model, a secure method that preserves the total supply of assets across chains while ensuring collateralization.

What is the Lock-Mint Bridging Model?

In a Lock-Mint model:

• The asset on the source chain (Ethereum) is locked securely in a vault contract.
• A wrapped equivalent token is minted on the destination chain (Supra).

There is no destruction, burning, or movement of tokens between chains.

Instead:

• Original tokens remain locked.
• Wrapped tokens represent a claim on the locked original.
• The minting only occurs after proof verification by HyperNovaCore on Supra.

How Lock-Mint Works in SupraNova

Example Flow

• You bridge 5 ETH from Ethereum.
• SupraNova locks exactly 5 ETH in the Ethereum bridge vault.
• After proof validation, Supra mints the equivalent amount of supETH to your wallet, minus any applicable service fee.

Collateral Status:

• ETH remains locked securely in Ethereum contracts.
• supETH is fully backed 1:1 by real ETH.

Security Guarantees

• No Double Spending: Because ETH remains immobile once locked.
• Full Collateralization: supETH minted on Supra cannot exceed ETH locked on Ethereum.
• Proof-Driven Minting: No minting happens without complete proof validation across transaction, receipt, and consensus.

Why is Lock-Mint chosen?

SupraNova chose Lock-Mint because:

• It is simple and verifiable.
• It aligns perfectly with Supra’s trustless, proof-based validation model.
• It avoids complexities like token burns, which are harder to verify without replay attacks or external watchdogs.

Assets Using Lock-Mint

Supra to Ethereum: Burn-Release

Most traffic back to Ethereum is Burn-Release, the natural inverse of Lock-Mint. It applies to every asset that originated on Ethereum and is held on Supra as a wrapped FA.

What is the Burn-Release Bridging Model?

In a Burn-Release model:

• The wrapped asset on the source chain (Supra) is permanently destroyed (burned).
• The original asset held in the vault on the destination chain (Ethereum) is released to the recipient.

There is no new minting on Ethereum, only unlocking of assets that were already locked during a prior forward bridge.

Instead:

• Wrapped tokens are irreversibly burned, reducing circulating supply on Supra.
• The matching original tokens are released from the vault.
• The release only occurs after proof verification by HyperNovaCore on Ethereum.

How Burn-Release Works in SupraNova

Example Flow

• You bridge 5 supETH from Supra.
• SupraNova burns exactly 5 supETH on Supra, permanently reducing its circulating supply.
• After proof validation, the Ethereum vault releases the equivalent amount of ETH to your wallet, minus any applicable service fee.

Collateral Status:

• ETH released from the vault always corresponds to wrapped tokens that have genuinely been burned.
• The vault balance and the circulating wrapped supply move in lockstep, preserving 1:1 backing at all times.

Security Guarantees

• No Double Spending: Because wrapped tokens are irreversibly destroyed before any release occurs.
• Full Collateralization: The total amount released on Ethereum can never exceed the total amount originally locked.
• Proof-Driven Release: No release happens without complete proof validation across transaction, receipt, and consensus.

Why is Burn-Release chosen?

SupraNova chose Burn-Release for assets returning to Ethereum because:

• It is the exact inverse of Lock-Mint, so the collateralization invariant is preserved without additional accounting.
• It requires no new asset issuance on Ethereum, only the release of assets already held.
• It aligns with Supra’s trustless, proof-based validation model, with the burn event serving as the verifiable trigger.

Assets Using Burn-Release

Supra to Ethereum: Assets Native to Supra

$SUPRA originates on Supra, so there is no wrapped balance to destroy when it leaves. Instead the outbound transfer locks it in the Supra-side vault, exactly mirroring how ETH is locked on Ethereum in the forward direction. The Ethereum-side token registered for that asset is then delivered to the recipient.

How the Supra-Native Path Works

Delivery on Ethereum takes whichever of the two forms applies to that token:

• Release from the Ethereum vault, when the destination token is a canonical ERC-20 the bridge holds in custody. This is the Lock-Release shape, and it consumes the Ethereum vault’s per-asset release limits.
• Mint, when the destination token is a bridge-issued representation. This is the Lock-Mint shape, and it never draws on the Ethereum vault, so the vault’s release limits do not apply to it.

The Ethereum-side representation of $SUPRA is 0xDC7404100A092c898E93708EF73F3322A7acc213 .

The Return Leg

Bringing $SUPRA back from Ethereum is the inverse again: the Ethereum-side balance is burned or locked according to how that token is issued, and the original $SUPRA is released from the Supra-side vault through token_vault::release_tokens. The Supra vault is therefore the mirror image of the Ethereum vault, with its own set_lock_limits and set_release_limits configuration per token.

Future Transfer Models

In future versions, the bridge will also support:

• Burn-Mint: Burning wrapped assets on Supra to mint another representation on a different destination chain, enabling Supra to act as a multi-chain routing hub.
• Batch Transfers: Batching multiple bridge requests, in either direction, into a single transaction to reduce per-transfer overhead.

These additional modes will allow Supra to offer both one-way and bi-directional bridging based on user needs and liquidity dynamics.