What exactly is blockchain?

September 1, 2023
Will Foulkes


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Blockchain is the technology that allows cryptocurrencies to work, cryptocurrency being money that works without the oversight of banks or general government.

But if you want to create digital money that works without banks, you have to overcome a key issue:  the double spend problem. Essentially, you need to stop people being able to spend their money more than once.

But how do you do that with no banks to oversee the spending?

The creators of blockchain looked back 400 years to take inspiration from the island of Yap in the middle of the Pacific Ocean. Their monetary system was based on something called rai stones, which were huge green discs of stone.

In this village, the chief would have a huge rai stone outside of their house. If they wanted to spend ‘money’, they couldn’t move the stone around easily, so they would gather all of the villagers together in one group.

The chief would announce something along the lines of: “I’m going to give 1/3 of this rai stone to Greg in exchange for his house so I’m going to transfer ownership. Has everyone got that?”. The villagers would say yes, meaning there was a community consensus approving and validating that transaction and preventing fraud. It stops the chief spending that rai stone multiple times, without the need for a central person to oversee the transactions.

The system used by the people of Yap is called a distributed ledger (because there’s no central person), and blockchain is also referred to as a distributed ledger technology (DLT). It is a trustless technology. You don’t need to trust in a single one of those villagers,, because you’re trusting in the majority consensus. This means that we can get rid of entirely centralised intermediaries. This is very exciting because it means we no longer really have the need for banks and large organisations to oversee our transactions, when the digital world can act as our consensus.

Blockchain is opening up possibilities that we’re only just starting to see now for cross-border trade, financial inclusion and all kinds of other new exciting things, such as NFTs and the Metaverse. We’ve come a long way in 400 years!

This blog was taken from our video series, “90 seconds with a gunnercooke expert”. Will’s episode can be found here.

You can contact Will or read more about his practice here.