Recently, the number of Internet banking transactions and e-financial services based on the public authentication certificate of smart-phones has rapidly increased. When using e-financial services by using the Android OS-based smart-phones, it is possible to experience the kind of problem related to the easy exposure of the user's personal information saved within a device together with the authentication certificate due to the security-related vulnerability in terms of the rooting attack against the android-based mobile device. As a result, throughout this thesis, the structure of e-financial transaction services based on smart-phones and the one of the authentication certificate saved within smart-phones were analyzed. Also, following the rooting attack, the exposure-related vulnerability regarding the information related to e-financial transactions, including the authentication-related files, was analyzed. Based on the results of the analysis, a method of establishing a safe environment for e-financial services was suggested.