If user changes the photo while my app is transferring it to a remote device, will the remote receive a corrupted photo? In iOS, is there a way to "lock" a photo using Photos Framework so that it cannot be modified by other app?
The remote won't receive a corrupted because the edit will not affect the file that you are uploading.
I don't think there is a way to "lock" a photo with Photo Framework.
I hope it helps! Good luck