Bitcoin's Blockchain Technology
Last updated
Last updated
Cryptocurrencies are part of a blockchain and the network required to power it. A blockchain is a distributed ledger, a shared database that stores data. Data within the blockchain are secured by encryption methods. When a transaction takes place on the blockchain, information from the previous block is copied to a new block with the new data, encrypted, and the transaction is verified by validators — called miners — in the network. When a transaction is verified, a new block is opened, and new bitcoin is created, or "mined", and given as a reward to the miner(s) who verified the data within the block. They are then free to use it, hold it or sell it.
Bitcoin uses the SHA-256 hashing algorithm to encrypt the data stored in the blocks on the blockchain. Simply put, transaction data stored in a block is encrypted into a 256-bit hexadecimal number. That number contains all of the transaction data and information linked to the blocks before that block.
The Bitcoin blockchain, specifically, is able to process about seven transactions per second, making it relatively slow for broad-scale transactions as compared to payment processors like Visa. Its slow transaction time is due to its decentralization –– validators around the world must come to a consensus about each transaction before it gets baked into the blockchain. While this is good for security, it can hinder speed, which is why Bitcoin has gravitated more towards a gold-like store of value since its inception.
Transactions are placed into a queue to be validated by miners within the network. Miners in the Bitcoin blockchain network all attempt to verify the same transaction simultaneously. The mining software and hardware work to solve the nonce, a four-byte number included in the block header that miners are attempting to solve. The block header is hashed, or randomly regenerated by a miner repeatedly until it meets a target number specified by the blockchain. The block header is "solved", and a new block is created for more transactions to be encrypted and verified.