The Java Native Interface (JNI) lets Android apps tap into native C/C++ code for performance and interoperability, but it’s no security shield. Native binaries can be reverse-engineered just as easily as Java code. This article explores why obfuscation matters, how attackers analyze JNI libraries, and practical strategies—like using RegisterNatives, renaming methods, and applying C/C++ obfuscators—that raise the bar for reverse engineers. Ultimately, JNI should be treated as a performance tool, not a way to “hide” secrets.