Cryptocurrencies like Bitcoin use blockchains to validate transactions and record them in a public ledger. The system is designed to be tamperproof using advanced math and innovative software rules.Blockchains are maintained by people all over the world who verify and monitor transactions. This is called mining, and it’s an important part of what makes cryptocurrencies secure and transparent.What Is Blockchain?A blockchain is a distributed ledger with growing lists of records (blocks) that are securely linked via cryptographic hashes. The data in each block contains information about the previous block, a timestamp and transaction data. This chain of blocks is what allows transactions on a cryptocurrency’s network to be irreversible.Many cryptocurrencies like Bitcoin use the blockchain technology to allow secure and fast payments between individuals without any middlemen. This also eliminates fees that would otherwise be charged by third parties like banks.Another use of blockchain is in product tracking and other types of record-keeping. For example, blockchain can be used to track food products throughout their journey from the farm to your pantry, or in an online game such as Rollercoin to let players trade virtual goods that are backed by real-world value.Most blockchain networks are decentralized, so no single entity maintains the system or controls it. This promotes transparency and security and reduces the risk of fraud or manipulation. However, it also means that the network requires more electricity to validate transactions.What Does It Look Like?Cryptocurrency has gained popularity over the past few years, but many people don’t understand how blockchain technology works. It has a reputation for being impenetrable, but it actually has major business applications and potential to revolutionize industries from the bottom up. The blockchain is a decentralized, public ledger that sustains an ever-growing list of transactions called blocks. Each block contains a record of transaction data, a timestamp and the proof that a miner successfully created it. This creates inherent blockchain security, making it nearly impossible for thieves to change or alter information on the chain without being detected.The best known use of blockchain is in cryptocurrencies like Bitcoin. However, this is only one of many possible applications for the technology. It’s also used to validate transactions on a distributed network and prevent double-spending digital currency. It also reduces costs by eliminating middlemen and other third parties. Unlike cash, cryptocurrency is not tied to any government or institution and can be transferred directly between individuals or companies on the blockchain network.Is Blockchain Tamper-Proof?Traditional ledgers can be tampered with, which makes it hard to trust the records they contain. Blockchains address this issue by cryptographically sealing transactions in a way that is impossible to reverse or edit.To become a part of the blockchain, new data must pass an audit. This is done by a group of nodes known as validators or miners, who verify the data using complex algorithms. If the data is deemed to be valid, it is added to the blockchain as a block.If a block is tampered with, the miners detect this anomaly and reject it from the canonical chain. Moreover, because all blocks in the blockchain are based on information from previous ones, any attempt to edit a record will break the chain, making it unusable.What Is Mining?The blockchain network is secured by miners—vast, decentralized networks of computers around the world that verify and secure transactions on the bitcoin and other cryptocurrencies ledger. In return for their processing power, these computers are rewarded with new coins.Mining is complex and resource-intensive, requiring specialized computer hardware that solves incredibly difficult mathematical problems. This requires a huge amount of electricity, driving up operating costs and drawing criticism from environmental groups.Mining is the mechanism that prevents the Bitcoin and other cryptocurrency network from being attacked or double-spent, as it removes almost all people from the verification process. It also reduces the time it takes to record a transaction, because each block contains the previous hash of all the transactions it includes. The blockchain’s design allows only 1 megabyte of transaction data to fit into a single block, which limits the number of transactions that can be validated in a given time. The current reward for mining a Bitcoin block is 6.25 bitcoins.