What's the best encryption algorithm for the iPhone in terms of speed and security?

Question

The iPhone supports the following encryption algorithms

enum {
    kCCAlgorithmAES128 = 0,
    kCCAlgorithmDES,            
    kCCAlgorithm3DES,           
         


        

Answer 1

Of those algorithms you list, I believe RC4 is the fastest. In addition, the speed of RC4 does not depend on the key length once it has been initialized. So you should be able to use the maximum key size for that one without worrying about runtime cost.