I will have a question for you, dear forum residents. I have a .jar file encrypted with ZKM which I think will work for me. I don't know how to decrypt this, can you help me?

  • ZKM (Zelix KlassMaster) by default obfuscates code, not encrypts it (exception: strings). Therefore there is no decryption. The names that have been obfuscated are gone unless ZKM forgot some identifier which can be used to reconstruct the original class name (but I don't think that the ZKM authors made such a mistake).
    – Robert
    Aug 5, 2020 at 11:08
  • So we can't remove it from this software?
    Aug 6, 2020 at 7:46
  • 1
    I’m voting to close this question because not related to reverse-engineering. Aug 7, 2020 at 22:56
  • I also vote to close this question. In case the OP wanted to know how to decompile the JAR file, I suggest benf.org/other/cfr with obfuscation mapping files.
    – ikaerom
    Aug 11, 2020 at 23:38
  • I don't agree with closing the issue. OP made a grammatical mistake, using "decrypt" instead of "deobfuscate". There clearly exist solutions for this sort of problem and I don't see how this could possibly be justified for closure under the premise of "not related to reverse-engineering" aside from the lack of awareness of the subject matter.
    – Col-E
    Aug 18, 2020 at 17:43

1 Answer 1


There are a few open source tools that make removing obfuscation patterns quite easy. Some have explicit support for ZKM. Here are are the two popular ones:

And here is one specifically for android:

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.