Abstract: People are getting used to use varieties of social applications on Android for communication in daily life or in the workplace. However, users’ data transmitted and stored over the Internet might be compromised because the service providers of social applications hold and use data opaquely. We try to find a solution to protect user privacy from the potential risks by modifying the social application installation package, using the technology of application repackaging, reverse analysis and hook. In the solution, users can choose if to encrypt the transmission of text, voice, pictures, files and other communication forms on social software. The test shows that the users using the proposed solution can achieve confidential communication within the group, which provides users with more reliable communication channel.