This obfuscator produces files that will not verify on Java 7, to get past this use the following flag: -XX:-UseSplitVerifier when running code that is modified with this obfuscator. This shall be addressed soon. Obfuscates Java class files, currently supports: - field renaming - string encryption Run as: java -cp bcel.jar com.speed.ob.Obfuscate files... where files are the .class or .jar files that you wish to obfuscate. .class files will be replaced and the original files saved as name_bak.class .jar files will be retained and the obfuscated file will be written as name_ob.jar