There are also two static methods that instantiate the class and encrypt/decrypt the message. It currently uses the same IV for every call, but I’ll eventually fix that. So don’t use this for anything important.
The U.S. government uses AES for TOP SECRET information. Or at least they did at one time, I don’t think anyone really knows what they do. There have been side-channel attacks on AES, but in my opinion, those don’t count. An example of a side-channel attack would be watching someone type in their password.