A Beginners Guide To Understanding The Byzantine Generals Problem

The term “Byzantine Generals Problem” was first described in 1982. It describes a situation where the involved parties must agree on a single strategy to avoid complete failure, but some of the involved parties are not trustworthy and can send false information, and in term the whole strategy becomes unreliable. No, this is not a history lesson, but a beginner’s lesson in one of the computer science problems and a way to better understand Bitcoin and the value it holds.

Imagine several medieval armies, surrounding a city, which they like to conquer. Each army is controlled by a single general, and they all must work together to make this siege successful and conquer the city. But, the generals are known for their corruption and untrustworthiness, which makes the coordination between the armies nearly impossible. The problem is that the generals do not know who is loyal and who is a traitor. So, how can the generals reach a collective decision, and be 100% sure that all the other generals received the correct messages and make it possible to execute the collective orders? How can they execute the plan, without relying on a single trustworthy person to send the correct messages to the generals?

Here comes Bitcoin to the rescue! Bitcoin uses a distributed ledger that functions as the generals’ distributed attack. Input to the ledger, as the general’s attack messages, must be trusted. Much like the troops surrounding the castle, how can a network trust all other members and ensure that the messages are valid? All participating members on the network must agree on every message that is transmitted. If a member or a message is corrupt, then they are resisted and the network will not be affected. Before a message is broadcast to the network, a miner is required to compute complex proof-of-work computations. Solving this, the miner produces a hash which in turn can be validated as true, and a consensus will be reached.

In the case of the “Byzantine General Problem” proof-of-work on the distributed ledger (see Bitcoin block explorer) ensures that the generals will only receive trusted messages, which in turn guarantees successful coordination between the armies.

All inventions are the result of a problem-solving process that comes from the circumstances in which these problems are present. A solution is always a product of the environment where the problem occurs, and Bitcoin is no exception.

Because of this revolutionary technology, today we have a “trust machine” that can help us validate actions and produce solutions where trust is not appointed to a single person, company, or government. But instead, it is written in computer code and that same code runs on thousands of distributed machines around the world, making the network resilient to a single point of failure, which looks more like the internet we have today.

I hope this article makes you a bit smarter and helps you better understand the value of Bitcoin. Leave your thoughts in the comments.