Question

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.

Answer 1

(a) When it is started to keep the secrecy using the secret key or the complexity of the mathematical algorithm and working on binary bit sequences, it is considered as science rather than art where the concept was security through obscurity.

(b)

Yes, cryptography is unconditionally useful. Yes helps to transmit confidential data with ultimate security. It helps to maintain confidentiality, authenticity and data integrity. So this is unconditionally useful.

(c)

Kerckhoffs's principle reformulated by Claude Shannon says that there is no need to hide the scheme of cryptography from the enemies. It is formulated with the conception that enemies know the system. Shannon's maxim is accepted by a wide range of cryptographers, which says that it needs to design the system in such a way that it can be fully familiar with the enemies.

(d)

The two fundamental properties that ensure cryptographic security are:

a)Privacy or Confidentiality

b) Authentication