I am searching for some cocoa code on AES encryption and I did some google search for it. I found this very useful link - http://iphonedevelopment.blogspot.com/2009/02/str
thanks for the great category extension. One thing that I've discovered - when you use CCCrypt with an algorithm stronger then 64 bit, you need to be compliant to the BIS export regulations. See the iTunes Connect FAQ for more details. Even if you use Apple's inbuild crypto api you need to get approval from the BIS.
There was a discussion on sf about this topic before (in context of ssl usage):
Using SSL in an iPhone App - Export Compliance
Best Regards Chris