iblock: An OMNeT++ Library for Bitcoin Simulation

Since the Bitcoin's release in 2009, numerous cryptocurrencies and blockchain-based technologies have emerged, each requiring careful consideration of performance and security issues. This work introduces iblock, a comprehensive C++ library and simulation model for the Bitcoin protocol, enabling simulations across various layers of a Bitcoin network (network, consensus, incentives, data). Designed for OMNeT++, iblock enables detailed network-layer simulations, while its in-depth representation of Bitcoin's data structures and algorithms facilitates experiments across consensus, incentive mechanisms and data management. The integration with other OMNeT++ libraries allows even more detailed simulations. iblock modular and extensible architecture allows for the seamless addition of new features and behaviors, providing a valuable framework for studying their effects on the Bitcoin network. We benchmark iblock's features and performance against other blockchain simulators proving that iblock is more efficient than other state-of-the-art simulators, validate its accuracy by comparing simulation results with related studies and real Bitcoin network data, and showcase iblock's capability to simulate different scenarios such as the selfish mining attack. Finally, we discuss iblock's limitations and potential areas for future development.