Tianyi U-Shield is a service that loads digital certificates and keys on the U-Shield client, and encrypts and signs sensitive transaction information on the Wing Payment mobile phone client by software, thus providing more secure transaction protection. After using Tianyi U Shield, all transactions and sensitive information processing protected by Tianyi U Shield can only be completed in mobile phones with digital certificates. Without a certificate, even if the payment password is stolen, the payment transaction and the modification of sensitive information cannot be completed.