A distributed, tamper-resistant digital ledger in which records (blocks) are linked using cryptography and stored across many computers rather than a single central authority.
- Each block contains data, a timestamp, and a cryptographic link to the previous block; altering one block breaks the chain, which makes records hard to tamper with.
- It is decentralised (no single controller) and uses a consensus mechanism so that many nodes agree on the shared record.
- Cryptocurrencies such as Bitcoin run on blockchain; the technology is broader than cryptocurrency and also supports smart contracts and supply-chain tracking.
- The Reserve Bank of India has launched a Central Bank Digital Currency, the Digital Rupee (e-rupee), as a pilot; this is sovereign currency, unlike private cryptocurrencies (verify the latest status).
- Uses include land-record management, secure document verification, and traceability; concerns include energy use and the misuse of anonymous crypto for illicit finance.
Blockchain, cryptocurrency, and the Digital Rupee are recurring science, technology, and economy current-affairs items, with a financial-crime and security angle.
Blockchain is the technology; cryptocurrency is one application of it. A Central Bank Digital Currency (Digital Rupee) is issued by the RBI and is legal tender, unlike private cryptocurrencies.
A decentralised, tamper-resistant digital ledger of linked blocks; cryptocurrency is one of its applications, distinct from the RBI's Digital Rupee.