SimBlock: A Blockchain Network Simulator Blockchain, which is a technology for distributedly managing ledger information over multiple nodes without a centralized system, has elicited increasing attention. Performing experiments on actual blockchains is difficult because a large number of nodes in wide areas are necessary. In this study, we developed a blockchain network simulator SimBlock for such experiments. Unlike the existing simulators, SimBlock can easily change behavior of nodes, so that it enables to investigate the influence of nodesu0027 behavior on blockchains. We compared some simulation results with the measured values in actual blockchains to demonstrate the validity of this simulator. Furthermore, to show practical usage, we conducted two experiments which clarify the influence of neighbor node selection algorithms and relay networks on the block propagation time. The simulator could depict the effects of the two techniques on block propagation time. The simulator will be publicly available in a few months.

Simulating, OffChain and OnChain: AgentBased Simulations in CrossOrganizational Business Processes Information systems execute increasingly complex business processes, often across organizations. Blockchain technology has emerged as a potential facilitator of (semi)autonomous crossorganizational business process execution; in particular, socalled consortium blockchains can be considered as promising enablers in this context, as they do not require the use of cryptocurrencybased blockchain technology, as long as the trusted (authenticated) members of the network are willing to provide computing resources for consensusfinding. However, increased autonomy in the execution of business processes also requires the delegation of business decisions to machines. To support complex decisionmaking processes by assessing potential future outcomes, agentbased simulations can be considered a useful tool for the autonomous enterprise. In this paper, we explore the intersection of multiagent simulations and consortium blockchain technology in the context of enterprise applications by devising architectures and technology stacks for both offchain and onchain agentbased simulation in the context of blockchainbased business process execution.