Question

In a blockchain, which functionality would prevent a previous block from being modified?
A. cryptographic hashing
B. encryption
C. consensus mechanism
D.smart contracts

Answer 1

Cryptographic hashing would prevent a previous block from being modified.

Option (a) is correct.

Explanation:

• A blockchain is a list of records that contains data.
• Al the blocks in a blockchain are linked together through a system known as cryptography.
• In each block, there is a timestamp that contains the cryptographic hash of the blocks.
• The presence of cryptographic hash retrains a block from modifications and changes.
• Thus the data in any block of a blockchain cannot be changed.