Hi my friend, sorry for the delay on it, but I was exactly writing about it (http://blog.abstractj.org/articles/AeroGear-iOS-crypto/). 

Answering your question, AGRandomGenerator is our wrapper to provide random bytes for salts and IVs, the minimum established is 16 bytes. For symmetric encryption you must stick to standards: 128, 192 and 256 bits, but as far as I can tell our default was set to 256 bits. 

I hope it helps otherwise feel free to ask.

--
abstractj

On February 21, 2014 at 6:43:28 AM, Saravanan V (saru2020@gmail.com) wrote:
> > Hello Everyone,
>
> I just viewed the AeroGear-Crypto-iOS Library here :
> https://github.com/aerogear/aerogear-crypto-ios
>
> Can someone answer few of my questions:
> * What is the Algorithm being used for Encryption/Decryption?
> * What is the Key Length used? (Can we use 1024?)
> * What is the algorithm used for Digital Signature ?