Blockchain | Part 2

Let’s continue from the previous ramblings & break down a few parts:

Blocks

This is a collection, of a bunch of transactions that have been checked, verified & squashed into a block.

Analogy; Christmas

  1. Each person getting a present = Record.

  2. Each present wrapping their presents in their own wrapping paper (grandparents always use the same wrapping paper, every year 😅) = Block.

  3. Those wrapped presents are added to the Christmas tree = Blockchain.

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Analogy; Bank account

  1. Your bank statement = Blockchain.

  2. Receipt of all your shopping items = Block.

  3. Each item on that shopping receipt = Transaction/Record.

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Encryption

This is simply a way of scrambling a message (by using one or more mathematical techniques and algorithms) so strangers and people that you don't want to read it won't be able to understand it. The only way to make it readable again is by having the password or the key. There are a variety of encryption methods which we can cover in another section.

Analogy; Passing notes at school

  1. Remember passing notes to friends during class in school? It would usually involve asking someone to pass on a message scribbled down on a piece of paper to your friend at the other end of the class.

  2. However it could be read by one of the students passing it on or worse, intercepted and read by the teacher.

  3. So usually kids would use funny ways of encrypting the message which could be either using slang, backwards alphabet or even writing in code.

... Below are a few visual examples:

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Elementary School Cipher

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Hieroglyphics / Codes

Distributed Systems

A distributed system is a system that spread across smaller systems, meaning all of the power is not in one specific place, this means that it is much harder to hack/infiltrate these types of systems as you would have to take down all of the smaller systems and there could be many. This is sometimes confused with decentralised systems.

Analogy; Football Team

  1. The players try to execute certain plays/tactics, but no player can read the other player's mind.

  2. There is no shared memory/state among players, and the timing of the players can also be off. Each player has only a limited, incomplete view of the system (e.g., an evolving attack).

  3. Yet, the global objective for the team is well-defined: defend your goal post, and eventually, score a goal.

Analogy; Car

  1. The players try to execute certain plays/tactics, but no player can read the other player's mind.

  2. There is no shared memory/state among players, and the timing of the players can also be off. Each player has only a limited, incomplete view of the system (e.g., an evolving attack).

  3. Yet, the global objective for the team is well-defined: defend your goal post, and eventually, score a goal.

Consensus

Consensus is a way for a group to agree, specifically with blockchain we are referring to a group/network of computers agreeing that a transaction is correct.

Analogy; Voting

  1. Each person votes (digitally or on paper), then submits their vote = Transaction/Record.

  2. All votes are counted, by several different groups = Consensus method.

  3. Groups who counted the votes, share results and agree the numbers are correct = Consensus reached.

Analogy; Wedding

  1. Two people are being married = Transaction/Record.

  2. The crowd are asked to speak if they do not agree = Consensus method.

  3. If everyone stays quiet and allows the wedding to continue a non-verbal agreement has been reached = Consensus reached.

I hope this helps visualise some of the other concepts at some kind of basic level.

The last part is about use-cases & why I think this combination of technologies, systems & infrastructure matters 👉 Blockchain | Part 3