2. (30 points) Regarding "security beyond symmetric key encryption": (a) (2 points) What breakthrough has turned cryptography from an art into a science? (b) (2 points) Is cryptography unconditionally useful? Explain why. (e) (2 points) What principle demonstrates that is it a bad practice to keep encryption schemes secret? (d) (2 points) What are the two most fundamental properties based on which cryptographic security is guaranteed? (e) (2 points) What is the risk if critical information is kept in plaintext in system memory? (f) (20 points) Name two memory disclosure attacks that we studied and explain how they work