{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How do you ensure the validity of transactions and expiration time in a blockchain?","a":"Encryption algorithm: Blockchain uses  encryption technology to encrypt transaction information, allowing only users who possess the decryption key to access and process the information."}]}],"pr":"23b777dba9400112a8f1392dcd0389b63cff7b7eadf85fb967e0079bd1de907e"}