Virtual UTXOs

Brollup utilizes virtual UTXOs (VTXOs) as the peg and enables their use in smart contracts as payable constructs.

Brollup is, in short, coinswaps between VTXOs and calldatas. Like how Ark Network swaps VTXOs for new VTXOs, Brollup swaps VTXOs for calldata (plus new VTXOs).

VTXOs are always verifiable off-chain, and enforceable on-chain. Calldata, on the other hand, undergoes client-side validation; Bitcoin clients only see it as bytes, while Brollup clients read and interpret the bytes.

Since calldata is evaluated within the client-side validated context, and VTXOs are verifiable off-chain, a VTXO can be swapped for calldata that executes a payable condition in the smart contract.

Brollup combines calldata with VTXOs to execute payable contract conditions, where, for example, the contract can grant tokens to the msg.sender in exchange for paid Bitcoin, with the location of the payment VTXO derived from the calldata.

This covers >90% of DeFi use-cases, whether it’s listing an NFT for sale in exchange for Bitcoin, where the buyer pays with Bitcoin upon execution, or placing a token sell order on a decentralized exchange, where the filler pays with Bitcoin upon execution. All atomically executed, verifiable, scalable, and enforcable on Bitcoin.

Brollup use-cases