When communicating with an external blockchain, the block producer must wait until 100% certain that the transaction has been irreversibly confirmed by other blockchains before accepting it as a valid input. Using EOS.IO software-based blockchain and DPOS, and 0.5s DPOS block generation speed and Byzantine fault-tolerant irreversibility addition, it takes about 0.5 seconds. If any blockchain producer does not wait, it is like a deposit transaction that is later reversed, and may affect the effectiveness of the blockchain consensus. EOS.IO software uses both DPOS and aBFT to achieve rapid irreversibility.
9.3 Proof of integrity
When using merkle evidence from an external blockchain, there is a significant difference between knowing that all processed transactions are valid and knowing that no transactions have been skipped or omitted. Although it is impossible to prove that all recent transactions are known, it can prove that the transaction records are uninterrupted. EOS.IO software allocates a set of sequences for each instruction and each account to simplify operations. Users can use these serial numbers to prove that all instructions for those special accounts have been processed and are processed in sequence.