Plugin suggestion: permission to read

Hi,
I am looking for a plugin that can do the following.

For a training of 15 lessons i have 10 students (users). The lessons are in blogposts.
Student A will do lessons 1, 5, 6, 8 and 12
Student B will do lessons 1, 6, 7, 9, 11 and 13
Student C will do lessons 2, 5, 6, 8 and 15

This plugin should be able to select which student (user) is allowed to read a certain lesson (blogpost).
The students can all have the same userlevel.

I look forward to hear your suggestions which is a good plugin for this goal.

Rob