Perun: Virtual Payment Hubs over Cryptocurrencies

The Perun paper proposes a framework for 'virtual payment hubs' that allow users to open payment channels between one another without needing a direct, pre-existing on-chain channel between them. By leveraging virtual channel technology, the protocol enables users to establish transient, off-chain communication channels through intermediary hubs, significantly reducing the frequency of on-chain interactions. The authors introduce a formal security model to prove the safety and liveness of these virtual channels, ensuring that funds remain secure even if intermediaries act dishonestly. This research is a significant contribution to the field of state channel networks, providing a robust mathematical foundation for capital-efficient, high-frequency micropayments. By optimizing channel setup and settlement procedures, Perun advances the state of the art in off-chain network scalability, offering a flexible and modular approach to building interconnected payment systems.