Smart Contract

A smart contract is a program stored on a blockchain that executes automatically when predefined conditions are met, without a trusted intermediary to enforce the agreement. Computer scientist Nick Szabo coined the term in 1994, more than a decade before blockchains existed. Ethereum, launched in July 2015, became the first platform designed specifically to run general-purpose smart contracts.

Why it matters

Smart contracts replace legal enforcement with code, which removes counterparty discretion but introduces a new risk: the code itself. Once deployed, a flawed contract executes its flaws faithfully. The 2016 hack of The DAO, in which an attacker drained roughly 3.6 million ether through a reentrancy bug, showed that programmable money inherits every weakness of the program. The promise is lower enforcement cost and automatic settlement; the price is that bugs become financial events. Audits and formal verification have grown into an industry of their own for exactly this reason.

In the gold vs bitcoin debate

Bitcoin supports a deliberately limited scripting language rather than fully expressive smart contracts, a design choice that favors security and predictability over flexibility. Gold has no programmability at all: any conditional agreement involving gold requires lawyers, courts, or custodians. Bitcoin advocates argue that its restrained script already covers the monetary essentials, such as multisignature control and timelocks, without the attack surface that general-purpose contract platforms carry.