On the iPhone, I want to make a simple application with a textfield. You would input text, and press a button, and it would encrypt it and put the data on another textfield. You could then decrypt the data. For the longest time I have looked and the Certificate, Key, and Trust Services Reference (https://developer.apple.com/iphone/...ce.html#//apple_ref/c/func/SecKeyGeneratePair), but I do not know how exactly encryption works, what exactly an asymmetric pair is, or how to do anything with it. Also, I need to know if encryption is processor intensive, because that might mean I would need design changes in the long run.