iOS App Store requires checking that if an app implements encryption, it needs to comply with US export regulations.

As far as I could research, standardized encryptions, open-source encryption code and encryption that is built into the OS are not needed to be declared.

Tried looking into how Cipher, SecretKey and so on this is implemented in MobiVM, but did not found much.

Does somebody know the details if these are considered exempt or non-exempt and why?