3. 40 points Databases contain sensitive data that must be protected from unauthorized accesses. Consider the Student database that contains information about the students' contact information, grades, tuition, and financial support. The following relations are in the database; the underlined attributes are the primary keys: Sontactinfo(SSN,name, major, address, phone, emergency-person, emergency-phone) Grades(SSN, course, term, grade) Einancialasunport(SSN, tuition, financial-aid) (10) Briefly describe two requirements for each confidentiality, integrity, availability in the Student database. For example students' grades should be confidential Confidentiality needs: Integrity needs Availability needs (10) Recommend an access control model to enforce these needs. Justify your answer (10) Consider the following scenario: Suppose the following integrity constraints apply to a database containing the fact that Mediocrates is an Athenian: Every man is an Athenian, a Boeoti an, a Corinthian, or a Dorian. All Athenians and Corinthians are peaceable All Boeotians and Dorians are violent. Meuesses does not wish it to be known that he is peaceable. Reges a public nuisance, tries to find out about MK from a system that refuses to answer whenever the answer, together with the integrity constraints, would imply the secret: Rbivgleztz; Is Medisxaies an Athenian? System: I wil not tell you. Rbinglegu Is he a Boeotian? System: No. Rtiuglegus Is he a Corinthian? System No. Rbinglesus Is he a Dorian, then? System: I wil not tell you. Explain the privacy violation of Medecat data that he is peaceable