In my Android app I am communicating with a web service the data sent and responded are encrypted with AES encryption.
So what I do is the following. I\'m sending a base
I suggest you take a look at http://phpaes.com/. It's a free AES encryption library implemented purely in PHP; it's fast and very very simple to use.
At the very least, it allows you get one step closer to isolating the true source of the issue.
This might not be the answer you're looking for - but is there a specific reason you're manually encrypting this data instead of using SSL/HTTPS?
In most cases HTTPS will be easier to implement and more secure than manually implementing a symmetric cipher.