Which blockchain feature ensures that once data is recorded, it cannot be altered without network consensus?
- Decentralization
- Immutability
- Transparency
- Smart Contracts
Answer: Immutability
Immutability is achieved through cryptographic hashing and consensus mechanisms: each block contains hash of previous block, so altering any data changes subsequent hashes, requiring recomputation of entire chain. Decentralization prevents single-point control; transparency enables auditability; smart contracts automate logic. Core to blockchain trust model.