A system and method of processing a secure payment transaction

A device specific four factor authentication process for a mobile transaction in a system comprising a mobile computing device 3 e.g. a smartphone, an e-commerce website 5, an independent authentication webserver 9 and an independent payment service provider (PSP) 11, the user confirming the transaction with each of the authentication webserver and the PSP individually. The transaction may be initiated on the device or a separate computer and a secure payment or PAYDAP(RTM) option may be selected on the e-commerce website wherein the user of the smartphone provides a unique contact identifier, e.g. the phone number of the device, to the authentication webserver 100 which responds by sending a transaction payment request to the associated device 200. The user confirms the request by fulfilling the transaction payment request 300 e.g. by logging into a mobile payments application using a PIN, password or login name, and the authentication webserver then instructs the e-commerce website and ...