Lightweight Algorithm for Preventing Malicious Fork in the Bitcoin Environment

Blockchain is considered the most secure technology in data storing, which stores data in blocks. Therefore. Blockchain is a linked list structure but may be changed to a fork structure; a usefulfork or a malicious fork. The usefulfork may occur when the rules of the block are updated. On the other side, the malicious fork occurs when a miner has supercomputer properties that generate a set of blocks as a branch and does not publish this branch to the blockchain until the length of that branch is greater than the length of the main branch, or when two blocks saved at the same time in the blockchain. TVhen theseforks occur in the systenb a set of blockchain transactions will be rollbacked, user waiting times increases, and miner rewards increases illegally. In this paper, a Lightweight algorithm is proposed to avoid the malicious fork issue, and therefore rollback issue, users waiting time is reduced in the transaction process. The proposed algorithm is to make a single publisher in the system and divides the block construction into two phases. In the first phase, a miner generates a block and sends it to the memory pool. In the second phase, the memory pool will publish the block to the blockchain. The results show that the proposed algorithm has a good ability to avoid the malicious fork issue in the blockchain and the rollback issue thus minimize user waiting times.