Abstract: The present invention relates to a system (1) and method (100) which enables the SMSs to be sent encrypted and to be opened only in the mobile devices (2), wherein the SIM card belonging to the MSISDN, to which they are sent, is installed. The inventive system (1) comprises a mobile device (2) which can run mobile application and in which a SIM card can be installed, a content sender (3) which sends the confidential information of its clients via SMS, a data-base (4) wherein the encryption keys produced specific to the SIM card by the SIM card producer are stored, an SMSC (5) which transmits the information it receives to the mobile device (2), an encryption platform (6) which encrypts the SMS that will be sent, and an OTP sending platform (7) which receives the SMS content from the content sender (3), sends it to the encryption platform (6) and sends the encrypted SMS it receives from the encryption platform (6) to the SMSC (5).