Distributed systems use General Packet Radio Service (GPRS) to exchange information between different members of the system. The members of the system depend critically upon their ability to access internet connection in order to exchange data via GPRS and the system will shut down in case of unavailability of Internet connection. There is a strong need for developing another backup communication media. In this paper a data transaction method based on encoded Short Message Service (SMS) over Global System for Mobile Communication (GSM) is proposed. This new method guarantees the functionality of the system in case of inaccessibility to GPRS which may be not always available due to measures such as attacks that affect its availability. The proposed method is based on third party agent who can keep the address secrecy of both communicators besides keeping confidentiality, integrity and availability.