The complicacy in understanding concepts pertaining to blockchain technology continues to grow, especially for beginners. One of the notable concepts pertaining to the blockchain landscape which has been troubling beginners refers to the Byzantine Generals’ Problem. Why should you worry about the problem of Byzantine generals? The Byzantine Empire is a long-lost chapter in the books of history and there is no reason to think of it in a time when smartphones and high-speed internet dominate the world. 

However, the Byzantine generals have a lot to explain to us about the possibilities of system failure. When it comes to blockchain, the Byzantine Generals Problem solution becomes clearly evident in terms of consensus. Now, you might be eager to find out what is the Byzantine Generals problem. The following discussion will help you find the answer alongside reflecting on how blockchain fits in the problem.

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Definition of Byzantine General’s Problem

The Byzantine Generals’ Problem is one of the foremost theories implemented in the development of blockchain protocols. In other words, the Byzantine Generals Problem is basically a game theory problem. It provides a description of the extent to which decentralized parties experience difficulties in reaching consensus without any trusted central parties. Byzantine General’s problem basically asks about the ways in which members can collectively agree on a specific truth when any member cannot verify the identity of other members. 

The implementation of Byzantine Generals problem in blockchain draws major similarities to the theoretical proposition of the problem. The problem found theoretical backing for the first time in 1982 with the support of mathematicians such as Robert Shostak, Leslie Lamport, and Marshall Pease. Nodes in a decentralized network can take on the role of Byzantine generals. The primary objective of the Byzantine Generals problem focused on enabling a peer-to-peer network without any central authority to make correct decisions. What’s the catch here? 

The Byzantine Generals problem solution aims at ensuring that a decentralized network could still reach the right decision even if some of the nodes go rogue. So, in a way, the Byzantine General’s problem presents a vital opportunity for creating a truly trustless distributed system. It would offer the ideal foundation for ensuring trustless distributed systems without expecting ethical behavior from participants. 

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Background of Byzantine General’s Problem

The background of the problem is also a notable factor in understanding “what is the Byzantine Generals problem” beyond basics. In the Byzantine Generals problem, you have different Byzantine generals gathered around a besieged city with their own armies. Now, they all have to attack at the same time to take the city, or else they face inevitable failure. Another important factor in the Byzantine General’s problem is that some of the generals are corrupt and untrustworthy. Let us assume that five generals are prepared to attack a city. Due to the distance gap between their armies, the generals must communicate and coordinate for planning the attack. The generals use messengers for communicating their plans for the attack. However, sending messages through messengers ultimately leads to some failure scenarios in the Byzantine Generals’ Problem such as the following.

  • Imagine the scenario where the enemy captures the messenger and tampers the message or the generals never receive the message. 
  • What would happen if the messengers are spies and change the contents of the message?
  • What would happen if one of the generals is a traitor and sends a false message through the messengers?

All of these scenarios point out towards the dire consequences of failing in addressing the Byzantine Generals problem in blockchain. It is quite important to notice how critical thinking can play a crucial role in addressing the Byzantine General’s problem.

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Finding the Solution 

The Byzantine Generals problem example clearly outlines how important it is to resolve the problem. You can find an ideal solution with a protocol that can identify the faults before they happen. The protocol with fault-tolerant measures could help in making the best decisions in the face of uncertainty. So, it is reasonable to assume that the Byzantine Generals problem solution is more probabilistic than deterministic. Each general has a different location and needs a system that can provide better clarity on what to do. Here are some possible solutions to the Byzantine Generals Problem example with five generals circling a besieged city. 

  • If any general has not received an official message for attack, then it means that the generals would not attack. Therefore, generals can wait for a specific period of time and wait for receiving the message for the attack. If the period passes and they don’t receive any message for attack, they can retreat to the camp.
  • Generals could also ask for secret phrases from messengers as a Byzantine Generals problem solution. The secret phrase must be known only to the generals for verifying messages. In addition, the generals could also ask for the official seal of the other generals for verifying that the other generals actually passed the order. 
  • You could also think of a variation to the Byzantine Generals problem example in which a horseman from each general would ride towards the city as an indication of an attack. In such cases, the generals can agree on a condition to attack if three out of five generals have raised their banners. 

In all these scenarios, you can ultimately round up on some clear observations. The notable inferences from the solutions to Byzantine Generals’ problem are as follows.

  • The increased number of messengers could improve the chances of the message reaching the generals.
  • The loyal generals would follow the orders agreed upon and invest the necessary efforts in execution of the plan. 
  • If a major share of the generals receives the message, the outcome is potentially better.
  • In case of more loyal generals for carrying out the orders, you can expect better outcomes easily.

Blockchain and the Byzantine Generals Problem

Many people are often troubled about “What is Byzantine problem in blockchain?” and the answer ultimately draws similarities to the theoretical explanation. Decentralized systems such as blockchain are likely to experience the Byzantine General’s problem. Why? Decentralized systems do not have any credible information source or approach for verification of information received from other network members. Blockchain, however, presented the first proven Byzantine Generals problem solution with the Proof of Work consensus mechanism. The Proof of Work consensus mechanism provides the foundation for building a clear and highly objective set of rules for the blockchain network or protocol. Members of the network should showcase proof of adequate efforts for the creation of a block before adding the blocks to the blockchain. While the block creator has to incur heavy costs for the verification of blocks, they receive incentives for publishing honest information. 

The objective nature of the rules ensures limited possibilities for modifications or disagreement with the information on blockchain networks. In addition, the rules governing the validity of transactions are also objective in nature alongside the system for minting new tokens. Furthermore, blockchain also ensures immutability which shows that data has not been modified. So, all the members of the blockchain network could agree on the state of the blockchain and underlying transactions. Each node can verify the validity of blocks according to Proof of Work consensus requirements and transaction validity according to other specifications. 

Any member trying to broadcast false information would basically draw us back to the Byzantine Generals’ Problem again. However, all the nodes on the network would immediately identify the information as objectively invalid thereby ignoring it. Since the nodes on the blockchain network could verify all the information on their own, you can have a truly trustless system. 

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Byzantine Fault Tolerance Algorithm 

As you can notice clearly, the answers to “what is Byzantine problem in blockchain?” point towards the identification of possible faults. As a matter of fact, the Byzantine Generals Problem gives the ideal basis for the creation of a fault-tolerant consensus algorithm. The concept of Byzantine fault tolerance in blockchain aims for the development of algorithms that can enable systems to make uniform, cohesive decisions despite the presence of corrupt elements in the network. Here are some of the important traits you can find in a Byzantine Fault Tolerance algorithm for a solution to the Byzantine problem in the blockchain.

  • The algorithm should aim to achieve the maximum possible levels of agreement from the group.
  • The vote of each participant should have equal weightage.
  • People should be allowed to participate in the consensus process to ensure that it fulfills the condition of the true majority.
  • In addition, the algorithm should also empower collaboration among all participants for achieving the best possible solution for everyone. 

Bottom Line

Blockchain can definitely provide a reliable solution for the Byzantine General’s Problem. It provides an effective approach for secure communication alongside exercising trust in a highly uncertain environment. Blockchain offers a layer that you can trust without having to trust every person you interact with. It facilitates the solution to the Byzantine problem through a consensus mechanism that calls for all participants to reach at agreements on specific transactions and processes.

Furthermore, blockchain also employs fault tolerant measures and cryptographic security for avoiding any shortcomings. The Byzantine General’s problem has spurred many new consensus mechanisms used by new blockchain applications. Learn more about Byzantine General’s problem in detail now.

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*Disclaimer: The article should not be taken as, and is not intended to provide any investment advice. Claims made in this article do not constitute investment advice and should not be taken as such. 101 Blockchains shall not be responsible for any loss sustained by any person who relies on this article. Do your own research!