Explore the innovative PERUN virtual payment hub system for cryptocurrencies in this IEEE Symposium on Security & Privacy conference talk. Delve into the concept of off-chain payment channels and their advantages over traditional on-chain transactions. Learn how PERUN introduces virtual payment channels to enhance efficiency by eliminating intermediary involvement in individual payments. Examine the formal modeling and security proofs for this technique in the context of a payment hub with direct channels to multiple parties. Discover how PERUN can be implemented on any cryptocurrency platform supporting Turing-complete smart contracts, with a focus on its Ethereum implementation. Cover key topics including blockchain scalability, smart contracts, ledger payment channels, PERUN virtual channels, and performance analysis.