Documents collaboration and security
I'm planning to build a mobile application where users will be able to create documents and share them with other users. Unfortunately I can't set security per document. In a situation where users don't share their documents, each user has privalages for his own database, and everything is great and secure. The problem occures when I want to share one document from my database with another user. I can't give him read privilages because I want him to read only one document, not all of them.
What is the best way to achieve such goal?
Thank you in advance!