{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"What are the roles of public keys and private keys in blockchain?","a":"Digital Signing and Verification: Public keys and private keys are widely used in blockchain for digital signing and verification. The private key holder can use the private key to sign the data, while the public key holder can use the public key to verify the signature."}]}],"pr":"b525ba7b1a3d58efb85f0aa7b28b7befbd17891e4f8c048f1c58655e442e180d"}