{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How can the security of transactions be ensured in a blockchain?","a":"Tamper-proof:  Each block in the blockchain contains a link to the previous block, forming a chain-like structure. Once a block is added to the chain, it is almost impossible to modify the data in it, making the entire blockchain tamper-"}]}],"pr":"a55c340db5195127870974487a7b9441161d5c46e0f83870b7f55697154285f8"}