Lecture 7: Public Key Exchange

Asymmetric Encryption


(True/False) Asymmetric encryption is the same as symmetric, except a user has two private keys instead of one




One-Way Functions


Is the one-time pad (with an unknown-key) a one-way function?




Discrete Logarithm


(True/False) Given g^x (mod p) and p, it is difficult to find x even when given additional knowledge of g




Diffie-Hellman Key Exchange


Why can't Alice and Bob simply send their keys a/b to eachother in order to compute the shared g^(ab)?




Diffie-Hellman Key Exchange Security


When Malice performs the MiTM attack, she must pick the same g^m (mod p) that she sends to both parties




Detecting Pairing MiTM attacks


Why don't we always use this method of entering a digest of the derived key to check that the same key was derived?




Public Key Encryption and Semantic Security


What is the main difference between the IND-CPA and Semantic Security games we've seen in class?




El-Gamal Encryption Scheme


(True/False) In El-Gamal encryption, the exponent r must be random