We no longer support ad-hoc networks, this is an option that Apple made difficult if not impossible to use several OS versions ago as they tightened their OS security to improve their OS for iOS devices (since they run full version of OS X on their phones, changes to the phones affect desktop OS versions, that's Apple, not us).
In lieu of ad-hoc feature, we recommend using an external router instead to connect your computer to and your iOS devices to for control. This will solve your security issue.