Final answer:
The name of the massive public online ledger for recording cryptocurrency transactions is blockchain.
Step-by-step explanation:
The name of the massive public online ledger which records the time and amount of every finalized cryptocurrency transaction is blockchain.
The blockchain is a decentralized and transparent ledger that is maintained by a network of computers called nodes. Each transaction that occurs within a cryptocurrency network, such as Bitcoin, is recorded on the blockchain in a series of blocks.
The blockchain ensures the security and immutability of cryptocurrency transactions, as it requires consensus from the network of nodes to add new blocks of transactions to the chain.