posted 9 years ago
so again...what part - exactly - do you need help with?
At this point, we don't know if you need help downloading the JDK, writing a simple Hello, world program, if your GUI doesn't size properly, or any of about a million other possibilities.
It really works much better if you ask specific, focused questions.
Also, your statement "I want to encrypt a string with the private key of user" strikes me as odd...if a user has a private key, you don't have it. that's why it's PRIVATE.
Are you trying to send them something that only they can read, or are you trying to send them something that is demonstrably from you and only you?
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors