{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How to avoid duplicate usage of expired blockhash in transactions within the blockchain?","a":"In order to avoid the reuse of expired blockhash in transactions, a timeliness check mechanism can be introduced during the transaction processing. Specifically, after receiving a transaction request, the node first checks the generation time of the nearest few blocks in the blockchain to determine if there exists an expired blockhash.  If an expired blockhash is found, the transaction is rejected, and the user is prompted to regenerate the transaction. Meanwhile, the node will record the expired blockhash locally to prevent its reuse in subsequent transaction processing. This ensures that the blockhash in transactions remains valid, thereby avoiding the reuse of expired blockhash."}]}],"pr":"f2ae7fb73035e227d1fa626b3da66f116c1f40170fccfac15e029a88471d39b6"}