Assignments can be set up with certain controls to enable more security when handing out tests and quizzes. When you're setting up or editing an assignment, you will be able to toggle the "quizzes" option which will enable the following:
Password requirement: You can restrict access to the assignment with a password that you provide to your students. Passwords can be set per section and you can input your own password or choose to auto-generate passwords. You can access the passwords from the edit page and remove the password requirement at any time.
Students will be asked to input the password on the assignment preview page.
Locked submission: Students will only have one chance to submit their quiz and will be warned that they will not be able to access it again after submitting.
Access after due date: Students will not be able to access the content of the quiz after submitting or after the due date. They will only be able to access it after grades are released.
Grading and feedback: Any comments you provide while grading will not be visible to students until you decide to release the grades. Unlike in a standard assignment, students will not be notified that feedback is available until they can access the assignment content.
There is one restriction to tests/quizzes.
Late days: One of the advantages of enabling quiz mode is that students can't access the material after they submit after the due date, which preserves the content of the quiz. For this reason, late days are not allowed. If a student needs more time, you can grant them an extension and adjust their score afterwards.