Lets break the blockchain!
For digital currencies like Bitcoin or Ethereum to remain stable, all computers on the network must store the same information about previous transactions. We show what it would take for this consensus to break down and why it has never happened before.
Ethereum is the second largest cryptocurrency by market value (right after Bitcoin) and the first which is fully programable through smart contracts, allowing the creation of many different digital assets (stablecoins, tokens, NFT’s) which mimic the functioning of the traditional financial system. With one crucial difference – unlike in the traditional financial system, in Ethereum network there is no central place where all transactions are stored! Computers that relay and validate transactions in the Ethereum network each have their own copy of all transactions ever executed and have to ensure that their copy is identical to everyone’s else! If the consensus protocol breaks the network stops functioning as a valid payment service, which luckily never occurred during Ethereum’s eight years of operation.
However, we can still try to break the Ethereum consensus protocol! We will demonstrate a private copy of a fully functional Ethereum network running on portable Raspberry PI computers, each of which acts as a validator node that relays and validates the transactions. We will use several of such computers equipped with LCD screens to better visualize the content of their local blockchains – a record of all transactions which is built incrementally, block-by-block, through the consensus protocol. By manually changing speed of communication between the nodes we will show how consensus can degrade up to the point where, instead of one, there are multiple different blockchains in the network.
