Last Irreversible Block (LIB)

The last irreversible block (LIB) refers to the latest block validated on-chain, which cannot be altered or modified. This term is commonly encountered in blockchain protocols utilizing an Asynchronous Byzantine Fault Tolerant (aBFT) consensus mechanism. The confirmation process for blocks involves block producers proposing an irreversible block containing transaction records. Once the proposed block achieves majority acknowledgment from block producers, it attains irreversible status, signifying the validation of transactions.