Abstract: A client comprising an application for secure payment transactions is provided. The application runs on a personal mobile communication device and the client accesses a service provided by a server, which includes a payment gateway. Various security measures are included in the client-server communication related to executing payment transactions in a secure environment.

Abstract: A mobile communication device accepts payments and is capable of integration of retail business applications without additional hardware. It allows merchants to accept card present payments directly without any need for additional external hardware, such as Point of Sale (POS) terminals. The merchant can accept card present payments from a contactless credit/debit card, from a mobile smart phone or another mobile telecommunication device supporting payment card digitization, or from a mobile smart phone or another mobile telecommunication device that carries or can access and transmit relevant payment information.

Abstract: A client comprising an application for secure payment transactions is provided. The application runs on a personal mobile communication device and the client accesses a service provided by a server, which includes a payment gateway. Various security measures are included in the client-server communication related to executing payment transactions in a secure environment.