Smart Contracts in Ethereum: Architecture, Development, Applications, and Security Challenges

Abstract

Smart contracts are self-executing programs that run on blockchain networks and automate agreements without the need for a middleman. Ethereum took this idea further by introducing a programmable blockchain on which decentralized applications can be built using smart contracts, most of them written in Solidity. This paper takes a close look at Ethereum smart contracts — how they are structured, how they run, how they are built, the consensus mechanisms behind them, gas optimization, security weaknesses, and the kinds of real-world problems they are used to solve. It also touches on newer developments such as Layer-2 scaling, account abstraction, and formal verification. The paper closes by pointing to a few directions future research could take to make Ethereum smart contracts more scalable, private, and secure.