Along came Ethereum, another blockchain currency in 2015. It was proposed in 2013 but one key feature, smart contracts, dates back to 1993 when Nick Szabo proposed the smart contract.

Szabo envisioned digital markets and digital currencies and how cryptographic payment schemes could be used to buy a bag of potato chips from a vending machine. Actually, he was broadly speculating the use of data to purchase items.

Ethereum implemented more robust features including a EVM or Ethereum Virtual Machine that facilitates distributed processing of smart contracts.