  In this study, we propose PRETRUST, a new framework to address the problem of
the efficiency of payment process based on blockchain systems. PRETRUST is
based on the thoughts of consortium chains, supporting fast payments. To make
parties address transactions efficiently and scale out the capacity, the main
strategy is based on the guarantee mechanism and shard technology with a random
arrangement of transactions and consensus groups. In PRETRUST, the guarantee
process replaces the verification of a transaction on-chain to realize the
optimization of efficiency. And the model of a trusted execution environment is
utilized in the interactions between PRETRUST and public systems. Throughout
the paper, we discuss several transaction scenarios and analyze the security,
which shows that PRETRUST can guarantee security.
