The Byzantine fault tolerance system, or Byzantine Fault Tolerance (BFT), is a system that can solve the problem of the Byzantine army. Building a fault tolerant Byzantine system is a necessity, but also extremely difficult in a distributed system.
Advantages and Concerns With the pBFT Model
The pBFT consensus model was designed for practical applications and its specific shortcomings are mentioned in the original academic paper along with some key optimizations to implement the algorithm into real-world systems. On the contrary, the pBFT model provides some significant advantages over other consensus models.
Despite its clearcut and promising advantages, there are some key limitations to the pBFT consensus mechanism. Specifically, the model only works well in its classical form with small consensus group sizes due to the cumbersome amount of communication that is required between the nodes.
The pBFT model is also susceptible to sybil attacks where a single party can create or manipulate a large number of identities (nodes in the network), thus compromising the network. This is mitigated against with larger network sizes, but scalability and the high-throughput ability of the pBFT model is reduced with larger sizes and thus needs to be optimized or used in combination with another consensus mechanism.