Email the file to them?
Unless you need to send out a large number of individualized files for each student or need a compact record of what was given to each student, I would agree with Howard that emailing might be the easiest thing to do. Anything else that could be used will take quite a bit of work each time you add new files.
The only thing that would make any sense to me would be to create a database activity with separate groups in the common module settings, probably in a course dedicated to this. Set up groups one for each student, place only that one student in their group. Make 100 copies with one student name on each of them. Use Restrict access on the database to only that one student's group. That group/student would be the only one with access to that database. Teach students to a find in the browser to find their database so they are not fighting a scroll of death. Lots of work each time you need to post files, but students would have privacy. While you can't check to see if students actually read the files, you can see whether they accessed the course and their database in the Reports. If there is a next round, you just add a new entry with the new files in it.
If the student has access to the file so that they could upload it themselves, just add a Private Files block to your course. Each student can only see files that they upload.
