LockDown Browser adds a password to exams in Blackboard.
Posted by Respondus Support

In Blackboard Learn (Original View), LockDown Browser uses the test password functionality to ensure students are using LockDown Browser to access the test. When a test is configured to use LockDown Browser, a random password is added under the Blackboard test settings. This internal password is not something students need to enter, nor should you provide this password to students. Rather, the password is used by LockDown Browser to prevent students from accessing the exam unless they are using LockDown Browser.

Important: Instructors should NOT delete or modify this password once the LockDown Browser setting has been required for the test.  If the password is modified, students will receive a warning message and be prevented from accessing the test; the instructor will see a "Fix It" indicator in the Respondus LockDown Browser dashboard. Clicking "fix it" will restore the password in the Blackboard Learn quiz settings.

Again, the instructor should never provide this password to students. When a student accesses the test with LockDown Browser, the password is automatically entered by the browser. If the student cannot navigate past the password screen, and the password field is blank, it is an indication the student is trying to access the test with a standard browser (instead of LockDown Browser).

If the instructor DOES want the student to enter a password to access the test, this can be set in the Respondus LockDown Browser dashboard > Settings > Password to access exam (optional). 

Finally, the above explanation is only for Blackboard Learn (Original View). It does NOT apply for Blackboard Learn (Ultra View) which has a beautiful, seamless integration with LockDown Browser!