📝 Access Matrix in protection of Operating System

Q1. What does the setuid bit on a Unix file indicate?

💡 Difficulty: easy | ✅ Correct: B

Q2. Which statement best compares Unix’s setuid mechanism with MULTICS’s protection rings?

💡 Difficulty: medium | ✅ Correct: B

Q3. A system has users U1, U2 and files F1, F2. U1 owns F1 and sets setuid on it. U2 does not own F1. In the access matrix, which entry must temporarily appear when U2 runs F1?

💡 Difficulty: hard | ✅ Correct: D