Thursday, November 22, 2018

How a Blockchain Works

A blockchain system is a peer-to-peer network of validating nodes. Each node maintains the ledger of facts and history of updates.

Changes to the ledger are triggered by transactions proposed by external parties through clients. When triggered by transactions, blockchain participants execute business logic (called smart contracts) and follow consensus protocols to verify results.

When consensus is reached under the network’s rules, transactions and their results are grouped into cryptographically secured, immutable data blocks that are appended to the ledger by each participant. All members of the blockchain network can see the same transaction history in the same order.

In addition to all of its transactions and their results, each block includes a cryptographic hash of the previous block, which ensures that any tampering with a particular block is easily detected.