{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How to avoid double spending or double signing in a blockchain?","a":"Implement strict  account permission management: The blockchain system should have a strict account permission management mechanism to ensure that only users with legitimate permissions can participate in transactions. This can prevent unauthorized users from conducting malicious activities such as double spending or double signing."}]}],"pr":"eab949a44750cce651e5e2f4dce659c21f494019a7baf8dd166e548f33152d44"}