Frames should never insert other structures directly. This leads to conflicts if the import project or any other structure also includes this structure. Instead, you need to tell your consumer that they should also include your addiction. CocoaPods will do this automatically, so you must enable it. (If you are having problems with CocoaPods dependencies, you should ask a question about it and clear it. The whole point of CocoaPods is to manage these things.)
Please note that today I will release Swift version of RNCryptor in beta (or tomorrow, but I really hope today). This version connects to ObjC and will be the preferred version in the future. (The ObjC version will continue to be available for projects that cannot or do not want to include Swift.)