Byzantine Fault Tolerance Explained: BFT Consensus Algorithm

Byzantine Fault Tolerance (BFT) is one of the most important things that secures blockchain technology. This article of our blog will explain the concept of BFT, how it works and its role for the blockchain network. Here we go!

Role of BFT in Blockchain Networks

What is BFT? Byzantine Fault Tolerance is the way a distributed system works even when some nodes are broken or try to harm others. Let's break it down.

A critical component of decentralized networks is consensus, through which a group of people or nodes in the network come to an agreement on a particular decision or transaction. But how can a computing network remain functional if some of its nodes are malfunctioning, failing to agree on the state of the system, or behaving maliciously?

The BFT algorithm mentioned earlier helps to solve this problem by providing a more robust and secure mechanism for achieving consensus in a decentralized network despite the presence of malicious nodes or failures. The Byzantine fault tolerance blockchain protocol, like its refined version Practical Byzantine Fault Tolerance (pBFT), contains a specific set of rules that all nodes in the blockchain network must follow to agree on transactions. It does not require computer-intensive procedures and consists of counting the votes of nodes and reaching an overwhelming agreement.

What does this mean? It means that the primary role of the Byzantine Fault Tolerance algorithm is to protect against system failures through the use of collective decision making, and to reduce the impact of faulty nodes.

How Byzantine Fault Tolerance Ensures Security for Smart Contracts

The Byzantine consensus blockchain protocol and smart contracts are inextricably linked. The BFT enables decentralization and digital security so that smart contracts - computer programs stored inside the blockchain that track and enforce commitments in cryptocurrency transactions - can be created.

The BFT protocol and its more advanced versions such as Practical Byzantine Fault Tolerance (PBFT) have become a popular solution to the security problems of smart contracts and the blockchain network provided that:

• No more than '(n-1)/3' nodes are faulted out of 'n' nodes (total number of nodes);
• The time between when a participant's message is first sent and when it is received by another participant-addresser grows no faster than to infinity, and so on.

Benefits of Byzantine Fault Tolerance for Smart Contracts

Of course, like anything else in the world, the Byzantine Fault Tolerance blockchain protocol and Practical Byzantine Fault Tolerance algorithm have many advantages.

• Speed and Reliability

These methods are able to reach consensus quickly and reliably. And distributed systems built using BFT have high throughput. This is great for applications that require fast transaction processing times and high levels of security.

• Decentralization

Blockchain ensures that no single node or group of nodes can take control of an entire network.

• Security and Attack Resistance

Byzantine consensus blockchain protocol ensures that multiple copies of the blockchain are maintained, reducing the likelihood of data loss. In addition, it is designed to be fault-tolerant, which means it can continue to function even if a certain number of validators are compromised or unavailable.

• High Scalability

The algorithm allows the network to grow as new nodes are added and can handle a large number of transactions and users. The use of parallel processing and segmentation techniques contribute to this.

These advantages can be seen in the performance of Tendermint. Tendermint byzantine fault tolerance in the age of blockchains provides a secure consensus protocol with accountability guarantees, and is also characterized by high throughput, as it performs thousands of transactions per second on dozens of nodes distributed around the world with a latency of about one second.

Limitations of Byzantine Fault Tolerance

However, Byzantine Fault Tolerance blockchain protocols have their own problems.

For example, they are prone to Sibylla attacks, where one party can take control of a significant number of nodes or in other words the number of votes reaches 51%, i.e. majority. When there are more nodes, it becomes more difficult to regulate such situations and counteract it.

In addition, scalability is not always about good things. At each step of the procedure, nodes have to interact with each other, and the more such interactions there are, the longer it will take.

Advancements and Future Outlook to Byzantine Fault Tolerance for Smart Contracts

We have studied the part where Byzantine Fault Tolerance explained. Now we can draw some conclusions about the prospects of this consensus algorithm. For example, distributed systems built using the BFT protocol have high throughput. This means that they have the potential to handle a large number of transactions per second, the number of which will reach several thousand tens. We should also expect that all the limitations will be overcome and as a result this mechanism will open up even more opportunities in the cryptocurrency sphere.

And overall, BFT consensus mechanisms are likely to play an important role in the future of blockchain technology as the need for secure, efficient and scalable blockchain solutions continues to grow.

To better understand the key topics and technologies impacting the blockchain industry, continue reading our Cryptomus blog articles. Thank you!