  The world-changing blockchain technique provides a novel method to establish
a secure, trusted and decentralized system for solving the security and
personal privacy problems in Industrial Internet of Things (IIoT) applications.
The mining process in blockchain requires miners to solve a proof-of-work
puzzle, which requires high computational power. However, the lightweight IIoT
devices cannot directly participate in the mining process due to the limitation
of power and computational resources. The edge computing service makes it
possible for IIoT applications to build a blockchain network, in which IIoT
devices purchase computational resources from edge servers and thus can offload
their computational tasks. The amount of computational resource purchased by
IIoT devices depends on how many profits they can get in the mining process,
and will directly affect the security of the blockchain network. In this paper,
we investigate the incentive mechanism for the blockchain platform to attract
IIoT devices to purchase more computational power from edge servers to
participate in the mining process, thereby building a more secure blockchain
network. We model the interaction between the blockchain platform and IIoT
devices as a two-stage Stackelberg game, where the blockchain platform act as
the leader, and IIoT devices act as followers. We analyze the existence and
uniqueness of the Stackelberg equilibrium, and propose an efficient algorithm
to compute the Stackelberg equilibrium point. Furthermore, we evaluate the
performance of our algorithm through extensive simulations, and analyze the
strategies of blockchain platform and IIoT devices under different situations.
