I was not able yet to continue on the quest, i had to finish some other things first concerning the GPDR law.
I want to change my test stack and use the same piece of code which works on windows, and do a basic test and build from there. But i already know that encrypting and decryptng itself is not a problem on Andorid. It's where the Base64Encode/decode comes in. So i will try your suggestions, and also the one from Hermann.
Hopefully i can get started tomorrow, today was really busy. Had to go to an Amusement park with the family and ride the Rollercoaster



