It seems to me that this is no block level encryption solution (like dm-crypt in Linux). I found fsencrypt in the QNX 
document. However, in the document it mentioned "The fsencrypt utility manages the encryption of a Power-Safe (fs-qnx6.
so) filesystem. In order to use fsencrypt, you must have specified crypto=enable for fs-qnx6.so."

I have a flash device that is currently using FF3S file-system. Does fsencrypt works in this file system?