Possible to create an app w secure file upload function?

We are considering to develop an iPhone app which (roughly) will create images, and patient-related information will be included in each image. We are new to app development.


Quick Background:

The app must include the functionality to securely upload the created images to a server of user choice, so that doctors can share images between themselves within their clinic. We don't what to include server storage in the app, but would rather want to include a secure upload function in the app and thereby enable for users to set up there own server storage that would be suitable for this purpose.


Q: What secure (encrypted) file upload functionalities are available in iPhone app development and what server technologies can be considered in this context?