I’m working on a cryptography practice test / quiz and need an explanation to help me understand better.
- Reduce DDHP to DLP
- Explain why even adversaries with computationally unlimited resources cannot break an information–theoretically secure cipher.
- Show that if there exists a poly–time algorithm to solve DLP, there exists a poly–time attack on DH that allows to derive the session key from information, publicly exchanged by the communicating par- ties over an insecure communication channel, as well as from publicly available common knowledge.
- Show that a cryptosystem, that is indistinguishable under chosen plain- text attack and is homomorphic with respect to multiplication, is not indistinguishable under adaptive chosen ciphertext attack.
- Show that a cryptosystem that is indistinguishable under adaptive chosen ciphertext attack is indistinguishable under chosen plaintext attack. Hint: to show this, show that distinguishability under cho- sen plaintext attack implies distinguishability under adaptive chosen plaintext attack.
- Show that all proper values of the RSA public exponent are odd.
- Show that if there exists a poly-time algorithm to factor integers, then there exists a poly-time attack on RSA that can be used to derive a private exponent out of a public exponent and an RSA modulus
- You have a message m that you need to be signed by Alice. How do you obtain Alice’s signature on m without Alice knowing what m is? Describe the process in details.
Requirements: .doc file
Cryptography – RSA, DDHP to DLP quiz