A Trust Machine

The core innovation of blockchain is decentralized trust. Normally, transactions require a trusted intermediary — a bank, a notary, or a government. Blockchain replaces the intermediary with a distributed ledger that everyone can verify but no one can alter.

Every participant holds a copy of the entire ledger. Changing one record would require altering every subsequent block across thousands of copies simultaneously — a task that is computationally impossible with current technology.