67) A plaintext message can be changed into a ciphertext message by using
A) a password.
B) a digital key.
C) Answers A and B are both correct.
D) Neither answer A nor B is correct.
68) If Company A wants to send Company B a secure message, Company A will use Company
B’s public key to encrypt the message. Company B must then
A) use Company A’s public key to decrypt the message.
B) use its private key to decrypt the message.
C) use Company A’s private key to decrypt the message.
D) use its public key to decrypt the message.
69) A message which contains a digital signature
A) must be encrypted along with the signature.
B) must be sent once as plaintext and once as ciphertext if no message digest exits.
C) does not have to be encrypted when a message digest is used as a digital signature.
D) Answers B and C are correct.
70) Which statement below regarding keys is false?
A) Each user should create his or her own public and private keys.
B) Using a central office authority to create and distribute keys is highly recommended.
C) The longer the life of the key, the more security that must be applied to protect it.
D) Sensitive keys should be themselves protected by passwords.
71) Privacy is a major issue in electronic transactions. Therefore, the Internet should not be used
if
A) a bank uses a different digital signature for each denomination of currency.
B) digital signatures need to be issued for coins used in electronic transactions.
C) the IP address of one of the parties to a transaction needs to remain fully confidential.
D) All of these answers are correct.