A blockchain is a digital ledger in which blocks are linked and secured chronologically by cryptography. A blockchain’s block chain contains information on transactions done within a given time frame, as well as a unique identifier to keep them from becoming confused with other blocks in the chain. Cryptographic puzzles are used to generate blocks. Mining is the activity of resolving these challenges.
A block on the blockchain attracts a reward. Miners who solved the cryptographic hashing problem at the inception of the Bitcoin blockchain were rewarded with 50 BTC, for example. Blockchains are decentralized records. Instead of being kept in one central location, the blockchain is replicated across each user’s computer instead of being stored in a single place.
Meanwhile, the hash — a unique block identifier — is produced from the data contained in every prior block in the chain. This implies that to forge any record on the blockchain, a malevolent individual would have to modify every block on all instances of the blockchain.
Blockchains are so uncorruptable that they’re often referred to as “immutable” records of transactions. Today, most blockchains are open to the public. Bitcoin and Ethereum are two well-known cryptocurrencies. Anyone can check out a blockchain’s transaction history using a block explorer, which is a software program that displays the contents of blocks. Blockchains, on paper, provide users with an extremely high degree of anonymity.
Public blockchains are the standard, but private versions are being attempted for a variety of corporate and governmental applications.
