Virtual-Time-Accelerated Emulation for Blockchain Network and Application Evaluation.

Blockchain technologies are in the ascendant of transforming the ways we manage contracts, make transactions, and manifest own- ership of property. The trend calls for a realistic testing and evalua- tion platform for blockchain applications and systems. We present Minichain, a container-based emulator that allows testing proof- of-work-based blockchains on a commodity computer. Minichain contains a realistic and configurable network environment, which is missing in today's blockchain testbeds. This unique feature enables us to evaluate the impact of network events (e.g., cyber-attacks) and conditions (e.g., congested or failed links) on blockchain appli- cations. Meanwhile, Minichain allows the direct execution of un- modified application code in the containers for fidelity, and utilizes the virtual time technique to speed up experiments and improve the system scale that one can accurately emulate. In particular, we mathematically analyze the convergence of the proof-of-work- based consensus algorithm to show the effectiveness of virtual time. We evaluate the performance of Minichain across both net- work layer and application layer, and demonstrate its usability by emulating a selfish mining attack initiated from the network layer