PCNs are a promising solution for overcoming blockchain limitations, such as scalability and privacy, yet understanding their behavior in large-scale deployments remains challenging. Currently, only custom and sequential simulators for PCNs exist, which are limited to evaluating small-scale networks. Parallel simulations could prove fundamental to understanding PCNs and gaining insights to develop payment systems, such as blockchain-based Central Bank Digital Currencies, capable of handling real-world payment loads effectively. We presented CLoTH-over-ROSS, a PCN model inspired by the CLoTH framework suited to run in ROSS, a popular parallel discrete event simulator. In this paper, through extensive experimentation, we investigate the model’s ability to scale as the number of available computing resources increases, highlighting its performance benefits and identifying critical bottlenecks that hinder the analysis of very large networks. These findings offer valuable insights for designing efficient and parallel PCN simulators, which can support the development of scalable blockchain-based solutions.

Payment Channel Networks (PCNs) promise to solve the scalability (and privacy) issue of blockchains. Understanding them is a key pillar to define a payment system, such as a blockchain-based Central Bank Digital Currency, that can correctly sustain a real load of payments. So far, only custom simulators of PCNs exist, which however allow us to evaluate only small-scale networks. In this paper, building on the existing literature, we design a PCN model suited to run in ROSS, a popular parallel discrete event simulator (PDES). This PCN model enables large-scale network analysis and readily fits the existing 3-tier banking system. After validating it, we show the benefits of exploiting a PDES to analyze large scale networks. Finally, we release the ROSS-based PCN model in open-source.

Distributed Ledger Technologies (DLTs), when managed by a few trusted validators, require most but not all of the machinery available in public DLTs. To profit from this s tate of affairs, we inject a PoA (Proof-of-Authority) protocol into Bitcoin, replacing its PoW. Our PoA consensus algorithm-built on top of PBFT and FROST-exhibits Byzantine Fault Tolerance and Confidentiality of the network configuration an d of th e quorum of signers. As such, it may become a modern and safe foundation for payment systems used in stablecoins, sidechains, and CBDCs.