Paper 2023/086

Flyover: A Repayment Protocol for Fast Bitcoin Transfers over Federated Pegs

Javier Álvarez Cid-Fuentes, IOV Labs
Diego Angel Masini, IOV Labs
Sergio Demian Lerner, IOV Labs

As the number of blockchain projects grows, efficient cross-chain interoperability becomes more necessary. A common cross-chain protocol is the two-way peg, which is typically used to transfer assets between blockchains and their sidechains. The criticality of cross-chain protocols require that they are designed with strong security models, which can reduce usability in the form of long transfer times. In this paper, we present Flyover, a repayment protocol to speed up the transfer of bitcoins over federated pegs by allowing untrusted liquidity providers to advance funds for the users. Transfer times are reduced because liquidity providers do not have the same security requirements as the underlying cross-chain protocol. We illustrate the Flyover protocol on the cross-chain interoperability protocol that connects Bitcoin to the RSK sidechain and show how Flyover can reduce transfer times without reducing security. In addition to this, Flyover extends the cross-chain protocol by allowing liquidity providers to make smart contract calls on RSK on behalf of the user.

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blockchainbitcoinsmart contractinteroperabilitybridgerepaymentrootstockrsk
Contact author(s)
javier @ iovlabs org
dmasini @ iovlabs org
sergio @ iovlabs org
2023-01-26: approved
2023-01-24: received
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      author = {Javier Álvarez Cid-Fuentes and Diego Angel Masini and Sergio Demian Lerner},
      title = {Flyover: A Repayment Protocol for Fast Bitcoin Transfers over Federated Pegs},
      howpublished = {Cryptology ePrint Archive, Paper 2023/086},
      year = {2023},
      note = {\url{}},
      url = {}
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