I am looking for an iOS PDF app that will enable me to secure/lock a PDF. I currently have PDFPen Pro and PDF Expert but while I can encrypt a PDF, I am not seeing a way to secure/lock a PDF. What I want to do is give viewing rights only but without the ability to print or copy any of the text. I can do this using a MacOS app but as I’m in my 30 day trial of using only my iPad Pro, I want to see if this can be done on the iPad.
Any suggestions? Thanks!
To my knowledge there is no IOS PDF app supporting setting such permissions (neither PDF Pen Pro, PDF Expert, or the Adobe app).
In exploring alternatives, an option could be to use online services, that are useable on a mobile platform, such as:
I do not have experience with this platform, however it does state that it supports setting these specific permissions (however a that does require a Soda Premium subscription).
Hence, it can be done, but it does not come cheap 
IMO, there is no way to allow viewing & deny copy/print on any computer. Just photograph the screen and, if desired, OCR the image. Encrypted email solutions have the same vulnerability.
Agreed, however the barrier is made higher (making a copy now requires additional conscious steps)
I didn’t mean to sound argumentative. In years past, I’ve been ask to evaluate several packages that promised control of digital documents given to others. In general, they were reasonably able to prevent modification of the original document, but that was about all you could count on.