Designing highly complicated information and security systems violates what cybersecurity concept?

Your school’s Multi-Factor Authentication software isn’t very stable and frequently causes users to not be able to access the school’s online resources. While having MFA is a great example of Defense in Depth, the instability of this implementation causes an issue with what other cybersecurity concept?

Your grades and school records are protected by law and are not publicly available. What cybersecurity concept does this resemble?

An adversary has infiltrated the university registration system and changed their courses to have all of the easiest professors. What cybersecurity concept was violated in this scenario?

Your GitHub account has not been set up to include dual authentication with your cell phone and only uses a username and password for logging in. What cybersecurity concept are you not applying?