Optimal Endorsement for Network-Wide Distributed Blockchains

Blockchains offer trust and immutability in nontrusted environments, but most are not fast enough for latency-sensitive applications. Hyperledger fabric (HF) is a common enterprise-level platform that is being offered as blockchain-as-a-service by cloud providers. In HF, every new transaction requires a preliminary
endorsement
by multiple mutually untrusted parties called organizations, which contributes to the delay in storing the transaction in the blockchain. The
endorsement policy
is specific to each application and defines the required approvals by the
endorser peers
(EPs) of the involved organizations. In this article, given an input
endorsement policy
, we studied the optimal choice to distribute the endorsement requests to the proper EPs. We proposed the OPtimal ENdorsement (OPEN) algorithm, devised to minimize the latency due to both network delays and the processing times at the EPs. By extensive simulations, we showed that OPEN can reduce the
endorsement latency
up to 70% compared to the state-of-the-art solution and approximated well the introduced optimal policies while offering a negligible implementation overhead compared to them.