In this article, you will learn what is the Byzantine Generals Problem. The Byzantine Generals Problem is a game theory problem, which describes the difficulty decentralized parties have in arriving at consensus without relying on a trusted central party. If a thing would work out only when all the participating parties are reliable and work as an organized, it would be difficult to advance at the same time.
What is the Byzantine Generals Problem?
The fictitious story of Byzantine Generals Problem is about a set of Generals, and their armies surrounding a royal palace they want to capture. They must choose the exact time of their attack to have the best chances of success.
The Problem
There are multiple generals and multiple armies. Success can only be achieved if at least half of them attack at exactly the same time. If they fail to coordinate the timing of the attack, they will be defeated and lose the battle for sure.
To further complicate matters, they suspect certain generals are traitors, becoming disloyal and giving misleading signals about the timing of attack only increasing the odds of a defeat.
They can only communicate with the other generals via their messenger. Moreover, they have Unfortunately, they have no way to check the authenticity of the message that they receive from the messenger.
Centralized and Decentralized Systems
Only decentralized systems face the Byzantine Generals problem, as they have no reliable source of information and no way of verifying the information they receive from other members of the network. In centralized systems, an authority is trusted to publish true information and prevent false or fraudulent information from being spread throughout the network.
For example, in the traditional financial system, banks are trusted to show clients their balances and transaction histories in an honest manner. If a bank did attempt to lie or defraud their customers, a central bank or government is trusted to rectify the breach of trust .
Centralized systems do not solve the Byzantine Generals problem, which requires that truth be established without trust. Rather, they sacrifice trustlessness for efficiency and choose not to face the problem at all. However, centralized systems are vulnerable to corruption by the central authority.
How Bitcoin Solves the Byzantine Generals Problem?
Bitcoin was the first realized solution to the Byzantine Generals Problem with respect to money. Many proposals and projects preceding Bitcoin had attempted to create money separate from the government, but all had failed in one way or another.
As a monetary system, Bitcoin needed a way to manage ownership and prevent double spends. To achieve this in a trustless manner, Bitcoin uses a blockchain, a public, distributed ledger which stores a history of all transactions. In the Byzantine Generals analogy, the truth that half or more of the parties must agree to is the blockchain.
If all members of the Bitcoin network, called nodes, could agree on which transactions occurred and in what order, they could verify ownership of bitcoin and establish a functioning, trustless money without a centralized authority.
Bottom Line
Bitcoin aims to offer a standardized solution to the issue, whereby the commitment of over 50% of the computational power is enough to achieve consensus. This article shows what is the Byzantine Generals problem and how bitcoin solved.
