Paper 2019/162

Multi-Stage Proof-of-Work Blockchain

Palash Sarkar

Abstract

We introduce a new variant of decentralised, trustless, permissionless proof-of-work blockchain. The main novelty of the new variant is a multi-stage proof of work which is analogous to multi-stage pipelining used in hardware architectures. Among the possible advantages of using a multi-stage proof-of-work blockchain are the following. Reduction of the time for confirmation of a transaction and speeding up the overall rate of transactions processing without reducing the time for mining a block. Encourage cooperative behaviour among the miners so that the reward for mining a block is shared by a number of miners. Use of hardware incompatible hash functions for various stages so that it becomes very difficult for a single entity to attain major computational advantage over all the stages of the block mining. Improve security by making 51\% attacks more difficult to achieve and by providing resilience to selfish mining attacks. We believe that the new blockchain structure mitigates the problem of scalability without compromising security. By enforcing cooperative behaviour among the miners, reward for mining a block is more equitably distributed. This, in turn, will help in ensuring participation by a greater number of entities in the overall mining activity.