A system, apparatus, and method for processing payment transactions that are conducted using a mobile device that includes a contactless element, such as an integrated circuit chip. The invention enables the updating, correction or synchronization of transaction data maintained by an Issuer with that stored on the device. This is accomplished by using a wireless (cellular) network as a data communication channel for data provided by an Issuer to the mobile device, and is particularly advantageous in circumstances in which the contactless element is not presently capable of communication with a device reader or point of sale terminal that uses a near field communications mechanism. Data transferred between the mobile device and Issuer may be encrypted and decrypted to provide additional security and protect the data from being accessed by other users or applications. If encryption keys are used for the encryption and decryption processes, they may be distributed by a key distribution server or other suitable entity to a mobile gateway which participates in the data encryption and decryption operations.