Queuing Theory of Improved Practical Byzantine Fault Tolerant Consensus

In recent years, the use of consensus mechanism to maintain the security of blockchain system has become a considerable concern of the community. Delegated proof of stake (DPoS) and practical Byzantine fault tolerant (PBFT) consensus mechanisms are key technologies in maintaining the security of blockchain system. First, this study proposes a consensus mechanism combining DPoS and PBFT, which can rapidly deal with malicious witness nodes and shorten the time of block verification. Second, the M/PH/1 queuing model is used to analyze the performance of the proposed consensus mechanism, and the performance of the improved practical Byzantine fault tolerant consensus mechanism is evaluated from steady-state conditions and key performance measure of the system. Third, the current study uses the theoretical method of open (Jackson) queuing network, combined with the blockchain consensus process, and provides theoretical analysis with special cases. Lastly, this research utilizes numerical examples to verify the computability of the theoretical results. The analytic method is expected to open a series of potentially promising research in queueing theory of blockchain systems.

Intrusion Detection Analysis of Internet of Things considering Practical Byzantine Fault Tolerance (PBFT) Algorithm

In order to improve the security performance and accuracy of the Internet of things in the use process, it is necessary to use the Internet of things intrusion detection method. At present, the problem of inconsistency between the accuracy of detection results and nodes is more prominent when the Internet of things intrusion detection methods are running. This paper proposes a practical Byzantine fault-tolerant intrusion detection method for the use process of the Internet of things. This method introduces the intrusion detection method and the operation function of foreign attackers on the basis of practical Byzantine fault tolerance; using the expected utility function to the corresponding benefit function of practical Byzantine fault tolerance, the results of Internet of things intrusion detection model can be effectively calculated. Finally, the experimental results show that compared with the existing intrusion detection methods, the proposed method can effectively reduce the energy consumption of the Internet of things in the operation process, can effectively reduce 14.3% and 7.8%, and can effectively reduce the energy consumption of the Internet of things in the operation process.

Practical Byzantine Consensus for Internet-of-Things

Use of IoT/WSN assisted smart-systems in the current age is making our living much more easier. However, components of such systems bear a high chance of getting compromised which may result in a substantial damage or loss. Use of fault tolerant consensus protocols provides a way towards solving this problem. Existing solutions for IoT/WSN systems mostly assume simple non-Byzantine node failures which is not enough to solve the problem. To combat the presence of smart devices with malicious intention, Byzantine fault tolerance support is highly essential in building trustworthy decentralised system. Byzantine fault tolerance has not been addressed much in the context of IoT/WSN because of its inherent requirement of extensive data sharing among the nodes. In this work, we approach to bring a solution to the problem using synchronous communication. In particular, we recast the well-known \textit{Practical Byzantine Fault Tolerant} (PBFT) consensus strategy to an efficient form that is suitable for use in IoT/WSN systems. We demonstrate that our proposed design can work upto 80% faster and consume upto 82% lesser energy compared to a naive implementation of the strategy in publicly available IoT/WSN testbed having 45 nodes.<br>

Practical Byzantine Consensus for Internet-of-Things

Use of IoT/WSN assisted smart-systems in the current age is making our living much more easier. However, components of such systems bear a high chance of getting compromised which may result in a substantial damage or loss. Use of fault tolerant consensus protocols provides a way towards solving this problem. Existing solutions for IoT/WSN systems mostly assume simple non-Byzantine node failures which is not enough to solve the problem. To combat the presence of smart devices with malicious intention, Byzantine fault tolerance support is highly essential in building trustworthy decentralised system. Byzantine fault tolerance has not been addressed much in the context of IoT/WSN because of its inherent requirement of extensive data sharing among the nodes. In this work, we approach to bring a solution to the problem using synchronous communication. In particular, we recast the well-known \textit{Practical Byzantine Fault Tolerant} (PBFT) consensus strategy to an efficient form that is suitable for use in IoT/WSN systems. We demonstrate that our proposed design can work upto 80% faster and consume upto 82% lesser energy compared to a naive implementation of the strategy in publicly available IoT/WSN testbed having 45 nodes.<br>

Lodestone: An Efficient Byzantine Fault-Tolerant Protocol in Consortium Blockchains

We present Lodestone, a chain-based Byzantine fault-tolerant (BFT) state machine replication (SMR) protocol under partial synchrony. Lodestone enables replicas to achieve consensus with two phases of voting and enjoys (1) optimistic responsiveness and (2) linear communication complexity on average. Similar to the state-of-the-art chain-based BFT protocols, Lodestone can be optimized with a pipelining idea elegantly. We implement pipelined Lodestone and deploy experiments to evaluate its performance. The evaluation results demonstrate that Lodestone has a lower latency than HotStuff under various workloads.

Distributed Hybrid Double-Spending Attack Prevention Mechanism for Proof-of-Work and Proof-of-Stake Blockchain Consensuses

Blockchain technology is a sustainable technology that offers a high level of security for many industrial applications. Blockchain has numerous benefits, such as decentralisation, immutability and tamper-proofing. Blockchain is composed of two processes, namely, mining (the process of adding a new block or transaction to the global public ledger created by the previous block) and validation (the process of validating the new block added). Several consensus protocols have been introduced to validate blockchain transactions, Proof-of-Work (PoW) and Proof-of-Stake (PoS), which are crucial to cryptocurrencies, such as Bitcoin. However, these consensus protocols are vulnerable to double-spending attacks. Amongst these attacks, the 51% attack is the most prominent because it involves forking a blockchain to conduct double spending. Many attempts have been made to solve this issue, and examples include delayed proof-of-work (PoW) and several Byzantine fault tolerance mechanisms. These attempts, however, suffer from delay issues and unsorted block sequences. This study proposes a hybrid algorithm that combines PoS and PoW mechanisms to provide a fair mining reward to the miner/validator by conducting forking to combine PoW and PoS consensuses. As demonstrated by the experimental results, the proposed algorithm can reduce the possibility of intruders performing double mining because it requires achieving 100% dominance in the network, which is impossible.