  Blockchain is becoming a new generation of information infrastructures.
However, the current blockchain solutions rely on a continuous connectivity
network to query and modify the state of the blockchain. The emerging satellite
technology seems to be a good catalyst to forward offline transactions to the
blockchain. However, this approach suffers expensive costs, difficult
interoperability, and limited computation problems. Therefore, we propose
BcMON, the first blockchain middleware for offline networks. BcMON incorporates
three innovative designs: 1) it reduces the costs of offline transactions
accessing the blockchain through Short Message Service (SMS), 2) it validates
the authenticity of offline cross-chain transactions by two-phase consensus, 3)
it supports offline clients to perform complex queries and computations on the
blockchains. The prototype of BcMON has been implemented to evaluate the
performance of the proposed middleware, which can show its stability,
efficiency, and scalability.
