Which term refers to a digital currency that operates without a central authority?

• A. Cryptocurrency
• B. Blockchain
• C. Passwordless Authentication
• D. Big Data

Answer: (A)

Cryptocurrency describes a digital currency that operates without a central authority. It uses cryptography to secure transactions and a decentralized network (often built on blockchain) to validate and record those transactions. Because no single bank or government controls it, trust is established through consensus mechanisms and cryptographic proofs rather than a central issuer. Blockchain, while related, is the distributed ledger technology that records all transactions; it enables decentralization but is not the currency itself. Passwordless authentication focuses on verifying identity without passwords, not on digital money. Big data pertains to processing and analyzing very large datasets, not to currencies. So the term that best fits a digital currency operating without a central authority is cryptocurrency.