Network Security Essentials Applications and Standards 5th Edition – Test Bank

Network Security Essentials Applications and Standards 5th Edition By Willaim Stallings – Test Bank

Chapter 3:  Public-Key Cryptography and Message Authentication

TRUE OR FALSE

T F 1.  Public key algorithms are useful in the exchange of conventional

                                 encryption keys.

T F 2.  Private key encryption is used to produce digital signatures which

      provide an enhanced form of message authentication.

T F 3. 
The strength of a hash function against brute-force attacks

       depends solely on the length of the hash code produced by the

       algorithm.

T F 4.  The two important aspects of encryption are to verify that the

      contents of the message have not been altered and that the source

      is authentic.

T F 5.  In the ECB mode of encryption if an attacker reorders the blocks of

      ciphertext then each block will still decrypt successfully, however,

      the reordering may alter the meaning of the overall data sequence.

T F 6.  Message encryption alone provides a secure form of authentication.

T F 7.  Because of the mathematical properties of the message

      authentication code function, it is less vulnerable to being broken

      than encryption.

T F 8.  In addition to providing authentication, a message digest also

      provides data integrity and performs the same function as a frame

      check sequence.

T F 9.  Cryptographic hash functions generally execute slower in software

      than conventional encryption algorithms such as DES.

T F 10.  The main advantage of HMAC over other proposed hash-based

         schemes is that HMAC can be proven secure, provided that the

         the embedded hash function has some reasonable cryptographic

         strengths.

T F 11.  Public key algorithms are based on mathematical functions rather

        than on simple operations on bit patterns.

T F 12.  The private key is known only to its owner.

T F 13.
The security of the Diffie-Hellman key exchange lies in the fact

         that, while it is relatively easy to calculate exponentials modulo a

         prime, it is very easy to calculate discrete logarithms.

T F 14.  The key exchange protocol is vulnerable to a man-in-the-middle

                 attack because it does not authenticate the participants.

T F 15.  Even in the case of complete encryption, there is no protection of

        confidentiality because any observer can decrypt the message by

        using the sender’s public key.