Fundamentals of Block Chain Technology. This is course is for intermediate students who are interested to learn about Block Chaintechnology and Hyperledger. This Chapter deals with the Fundamentals of Ethereum. The invention of the blockchain for bitcoin made it the first digital currency to solve the double-spending problem without the need of a trusted authority or central server. The bitcoin design has inspired other applications and blockchains which are readable by the public are widely used by cryptocurrencies.