Hi! For my understanding, a signing tool should work like that: Take original data, decrypt it and encrypt with signs and hashes. That should be working again and again with the same (resigned) datas. *Without* watermarking and key modding and other things. After looking around i found 3 different (windows) frameworks of these tools: - command line based - python based - java based The java thing is working the described way, but with all the things a good hacker never would make: Watermarking, no source codes and more... The python thing is too freaky and more an all-in-one one click tool. The command line tools: After playing a little bit with make_npdata (v1.3.4), it seems this program have problems with generating correct hashes. You could test it yourself. Take original data, resign it and than take the resigned data and try to resign it again. You will get a *can't decrypt error*... So, let's talk about that. Any feedback, hint, solution, fix is welcome. Greets.