On the Scalability of a Blockchain Network based on the Practical Byzantine Fault Tolerance Consensus Method

In this work, an investigation is carried out on the architecture of the blockchain networks and the different consensus methods that the network uses to write the transactions on a blockchain. In particular, it focuses on the practical Byzantine Fault Tolerance (pBFT) consensus method. First, a bibliographic and systematic review of the networks using this type of consensus was carried out; then it evaluates the number of nodes and message replicas that a pBFT-based network must have for consensus to be possible. Such a review allow to understand that tolerance to Byzantine faults is associated with the number of nodes that replicate the message that is sent, taking into account that there is a way to calculate the minimum number of nodes that must exist to maintain consensus in these systems. In addition, such tolerance is a property of specific systems, that is, it is not exclusive to blockchain technology. Finally, the main blockchain networks that use the pBFT consensus method have been analyzed in detail, and we have evaluated the conditions under which these networks are working at the time of making this article.