How can I set hidden information between users?

Hello! I have this todo list and I created a login page that works fine. The thing is that I have 2 different users and after the login, bot of them see the same information (see the print). If user 1 set a new task and logout and user 2 login after user 1, he will see the tasks of user 1 and vice versa. How can I set hidden their info, make all their tasks private for each other?
1 answers

You can do this in 2 ways.. 

1. Set the association between user and his tasks. 

While showing the tasks retrieve by association. 

2. Add an xpath level security for accessing the tasks. If the user himself creates tasks then say only read and write for owner to be given as the access rule.