Question 3 (1 point) Saved In which of these attack scenarios is the attacker most powerful? Ciphertext only attacks Known plaintext attacks Chosen plaintext attack Question 7 (1 point) Assume Alice and Bob both have public and private keys in a public key setting. If Alice and Bob want to agree on a secret value, then Alice uses her key and Bob's_key to compute the secret value. private /private public / private private / public