Achieve space-efficient key management in lightning network

Abstract

The low transaction throughput, high transaction latency, and unfriendly micropayment are the main obstacles hindering Bitcoin use in time-sensitive environments. To mitigate these problems, various solutions have been proposed. The lightning network (LN) is considered one of the most promising ones, and it has been widely deployed in different versions. However, the LN itself is subject to a scalability problem due to the used channel state revocation technique. It especially requires O(n̄) storage cost to store the private keys, where n̄ is the number of transactions that happened in the channel and expected to be infinite. Though there are some techniques to resolve this problem, none of them is compatible with the current Bitcoin system. Aiming at solving this dilemma, in this paper, we propose two space-efficient Bitcoin-compatible key management schemes for the LN, based on the hash function and trapdoor one-way function, respectively. Both schemes reduce the storage complexity from O(n̄) to O(1). The detailed security analysis shows that our schemes hold the security level of the original LN or its variants. The extensive experimental results demonstrate that our proposed schemes are efficient and feasible, with a significant reduction in storage overhead.