What a pleasure to finally share the book with Chris Wing, who is an expert in Enterprise technology and a solutions consultant for Blockchain tech. Chris has added over 17 pages to Commercializing Blockchain and I think him for his time and more importantly, his deep expertise in Blockchain/DLT, and his two sections in the book on the complex world of Consensus and the understanding of different types of Blockchain/DLT networks
Firstly, I asked Chris to take us through the different types of consensus and he starts with taking us back to the age of the Roman empire.
Section 1 – Byzantine Generals’ Problem
To explain the Byzantine Generals’ problem, we must first take a trip back to the Middle Ages. Imagine you are a spectator on a Roman battlefield, witnessing the Byzantine army preparing to attack a castle in the middle of a field.
The army has the castle surrounded, with a battalion stationed on either side, each a mile from its edge so as not to be seen by the enemy. Each battalion is in the command of a General who fully controls their every move.
A successful attack can only happen if all battalions attack the castle at the same time, swarming from all sides will surely overrun the enemy. However, if each battalion attacks individually, they will all be defeated. The Generals could, in theory, send messengers to one another to coordinate the attack, but there is a chance these messengers will be intercepted and killed by the enemy. This could also result in imposter messengers with fake messages, leading to each battalion doing some- thing different and being defeated by the enemy.
Additionally, one of the Generals could in fact be an imposter agent and purposefully send fake information to other battalions, once again resulting in all battalions doing something different (i.e. attacking at different times or retreating) and causing defeat across the Byzantine army.
And thus here the problem lies; how can the Generals organize a coordinated attack (or retreat) on the castle in a reliable and trustworthy manner? In other words, how can the Generals come to a general consensus on what action to perform?
This problem can be translated into digital communication in the situation where unknown parties are exchanging information with one another on a network and the reliability of each source is unknown to the rest of the participants on the network.
Different Types of Networks
By Chris Wing
Chris also talks about the different types and here is his excellent section on the different types of Blockchain networks.
The different types of Blockchain networks have different roles and will achieve different tasks. I believe that we need to work in a hybrid world where the Blockchain networks are interoperable and work together. Over the next few years, we will see many more Blockchain networks and DLTs – all of these need to work together as the unique characteristics of each network, complementing each other and enabling a significant ecosystem of many different solutions.