Most Bitcoin systems use blockchain technology to store all historical transaction data. Blockchain is a linked list structure but may be changed to a fork structure; a useful fork or an intentional fork. The useful fork may occur when the rules of the block are updated. On the other side, the intentional 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. When this fork occurs in the system, a set of blockchain transactions will be rollbacked, user waiting times increases, and miner rewards increases illegally. In this paper, the Lightweight algorithm is proposed to avoid the intentional 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 intentional fork issue in the blockchain and the rollback issue thus minimize user waiting times.
Concept drift refers to sudden changes in the fundamental structure of the streaming data distribution over time. The core objective of concept drift research is to develop techniques and strategies for detect, understand, and adapt data streaming drifts. Data research has shown that if concept drift is not handled properly, machine learning in such an environment would provide subpar learning outcomes. In this paper, a historical Isolated Forest (HIF) is presented that depends on a decision tree, which split the data streaming into chunks and each chuck considers a region in the tree. HIF is employed to detect concept drifts and adapt this region with current changes. Which HIF stores previously generated models and employs the most similar model of each concept drift distribution as the current model until generate the best performance model. HIF doesn't stop the main system model when retraining a new model, which HIF is divided into three primary parallel blocks: detection block, similarity block (online block), and retraining block (offline block). For several authentic data sets (three data sets), our suggested algorithm was verified and contrasted. the accuracy and execution speed were specifically assessed, and memory usage. The experimental results demonstrate that our modifications use fewer resources and have comparable or greater detection accuracy than the original IForestASD.
Recently, blockchain is considered the most reliable data storage technology that stores data in blocks.Many cryptocurrency frameworks such as Bitcoin, therefore, utilize blockchain technologies to preserve all past details on blocks.These blocks are related as a chronological link list and can be changed to a fork structure.Which there are two types of fork: accident fork which appears when two blocks are published in the blockchain at the same time.On the other hand, there are selfish miner attackers who have supercomputer properties to generate illegal blocks and maximizing their illicit reward (intentional fork).A set of blockchain transactions will be rollbacked when the malicious fork appears in the Bitcoin environment, therefore, user waiting times and illicit miner rewards will increase.In this paper, The proposed algorithm is a lightweight algorithm (Memory pool publisher) that has used the Bitcoin memory pool as a publisher of blocks to prevent the Bitcoin environment's malicious fork and rollbacked transaction.The findings show that the major cause of the malicious fork is the multiplicity of blockchain publishers of blocks in the bitcoin environment.The proposed algorithm success to solve the limitation of the previous fork.Which has a strong potential to prevent the intentional and accident fork problem, and the rollback problem.Therefore minimize user waiting times from 60 minutes to 10 minutes by makes one block publisher to the blockchain.
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.