{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How to prevent the double-spending problem in blockchain?","a":"Whenever a transaction occurs,  miners bundle it into a block and compete to solve a winner to confirm the validity of the block."}]}],"pr":"dc03ac1a38c86e301f61c6065c87bedd6126922d2832798150b1fc262ba40d53"}