Video 4: Playing chess while learning how blockchain works
Time to put things into practice in the fourth video and zoom in on how a deterministic board game like chess demonstrates the logic of blockchain technology.
As demonstrated in previous weeks (yes, we are well under way with our videos on live contracts and blockchain), crucial elements of blockchain can be explained well by playing a simple game like Robot Turtle.
That was good fun, but now we go one step further. Hence, we focus on chess, a more sophisticated board game that is also deterministic, as we have heard in the second video, but something we have not yet seen in practice.
‘As is typical with a game like chess, my opponent and I both write down every move we make’, Arnold Daniels, co-founder of LegalThings One starts off in this week’s video. ‘In this friendly game this works well, as we both have a copy and know what the other’s moves are.’ But what if one of the two players makes a mistake in writing, accidentally or on purpose?
Time to reset the game. ‘My opponent makes a move, writes down his action and this time he signs the move’, Arnold analyses as he takes the same three steps as his opponent has done. ‘This is how we both get a copy of the game. If we replay the game, we are sure that the game is correct, since my opponent cannot forge my signature, neither I can forge his.’ But according to Arnold, there is always a catch. ‘I can still take out my move and change it without touching my signature.’
Ledger
So let’s once more reset the game. ‘Rather than writing down my own move, I also write down my opponent’s move and sign it.’ Arnold’s opponent does the same. This forms a chain, on which it is impossible to leave something out or having the risk of a forged signature. Of course, one of the two players can still cheat, but one will see that the game history no longer matches. As a result, the chain will be broken. ‘This is one of the basic elements of the blockchain. Together we create a set of papers, that we call a ledger’, Arnold says.
With two players this works well, especially when both have such a ledger. But what happens when we have another board with two players or even more, having the same conditions and actions? ‘You can see that it’s even more secure when not two but four persons possess a copy’, Arnold concludes.
Crowded
However, there are also a few downsides. ‘The more players get involved, the more crowded it gets. The size of the table is limited, so the number of participants is also limited’, he says. ‘Since we are playing the game together, there is no real reason for everyone to add their rules to a single ledger.’
Back to two players. ‘In this case, these players don’t have a lot to do with any other game. So it might be better to form our own ledger. It’s less secure, but we can take some steps to add security to the setup’, Arnold concludes. Do you want to know how this continues? Stay tuned for more next week!
