I am developing a mobile app that involves (essentially) picture messaging as a feature. I need the images to be encrypted/decrypted with a simple, plain-text password. Due to the nature of the images being captured, it is /critical/ that the encryption and decryption processes happen on the device.
After sitting through a presentation on mobile development in Flex, I have decided to create my app with the Flex SDK, which means I will be implementing the client application in ActionScript 3 and Flex.
One thing I want to do is show the image on the stage before AND after it has been encrypted. However, this is a nice-to-have, not a need-to-have.
Are there any known APIs/algorithms out there for what I am trying to do? I would also appreciate being pointed towards CPU-friendly encryption algorithms. I’ve tried Googling around, but it hasn’t been too much of a help for me.
I would suggest the as3crypto library. It should provide everything you need.
http://code.google.com/p/as3crypto/