  Bitcoin-NG is among the first blockchain protocols to approach the
\emph{near-optimal} throughput by decoupling blockchain operation into two
planes: leader election and transaction serialization. Its decoupling idea has
inspired a new generation of high-performance blockchain protocols. However,
the existing incentive analysis of Bitcoin-NG has several limitations. First,
the impact of network capacity is ignored. Second, an integrated incentive
analysis that jointly considers both key blocks and microblocks is still
missing.
  In this paper, we aim to address these two limitations. First, we propose a
new incentive analysis that takes the network capacity into account, showing
that Bitcoin-NG can still maintain incentive compatibility against the
microblock mining attack even under limited network capacity. Second, we
leverage a Markov decision process (MDP) to jointly analyze the incentive of
both key blocks and microblocks, showing that the selfish mining revenue of
Bitcoin-NG is a little higher than that in Bitcoin only when the selfish miner
controls more than 35\% of the mining power. We hope that our in-depth
incentive analysis for Bitcoin-NG can shed some light on the mechanism design
and incentive analysis of next-generation blockchain protocols.
