# Eavesdropping on a communication line

Question 1

1.

An example of an active attack is an attack where someone is eavesdropping on a communication line to capture information being transmitted.

[removed]True

[removed]False

Question 2

1.

How can a symmetric encryption algorithm be figured out or “cracked”?

A. Cryptanalysis

B. Denial of service

C. Man in the middle

D. Brute force

E. Eavesdropping

 [removed] 1 A, D [removed] 2 A, B [removed] 3 A, E [removed] 4 B, C [removed] 5 D, E [removed] 6 A, C

Question 3

1.

The number of passwords that can be generated from the set of characters {a,b,c,d} with replacement is? (replacement means you can use each character multiple times)

 [removed] 1 64 [removed] 2 24 [removed] 3 256 [removed] 4 512 [removed] 5 1024

2 points

Question 4

1.

The standard that defines and guides Public Key Infrastructure is:

 [removed] 1 X.800 [removed] 2 X.509 [removed] 3 RFC 3280 [removed] 4 Document – New Directions in Cryptography [removed] 5 ASN.1 for PKIX

2 points

Question 5

1.

Assume there are 256 possible keys in the universe of keys for a particular cipher. How many keys on average would need to be tried to break the cipher? Blank 1[removed]

2 points

Question 6

1.

A message is sent using a Message Authentication Code (MAC). An attacker intercepts the message, changes the message and sends it to the original recipient. The recipient of the message will not detect the change.

[removed]True

[removed]False

2 points

Question 7

1.

A block encryption algorithm encrypts fixed size blocks.

[removed]True

[removed]False

2 points

Question 8

1.

The number of passwords that can be generated from the set of characters {a,b,c,d} without replacement is? (without replacement means you can use each character once and only once)

 [removed] 1 24 [removed] 2 64 [removed] 3 128 [removed] 4 256 [removed] 5 512

2 points

Question 9

1.

Match the “value” with the technology.

 secret key Public key Private key Message digest Pseudo random numbers

 A. Hash algorithms B. PRNG C. Asymmetric encryption D. Symmetric encryption

7 points

Question 10

1.

A digital certificate is issued with a digital signature from a certificate authority. The digital certificate binds together a public key with an identity.

[removed]True

[removed]False

2 points

Question 11

1.

The difference between the DES and 3DES algorithms is?

 [removed] 1 DES is symmetric encryption. 3DES is asymmetric encryption. [removed] 2 DES uses 16 subkeys for encryption and decryption, 3DES uses 3. [removed] 3 DES uses 1 key for encryption and decryption; 3DES uses 3 keys. [removed] 4 3DES uses a Feistel network, DES does not. [removed] 5 None of the answers are correct.

2 points

Question 12

1.

Using a rail fence cipher with depth of 2 decrypt the following ciphertext: TEATIAMDIH HPRYSTINGT Blank 1[removed]

2 points

Question 13

1.

XOR the two values together.

Select the correct result.

0110 1011 1111

1101 1100 1100

 [removed] 1 0100 1000 1100 [removed] 2 1011 0111 0011 [removed] 3 None of the selections [removed] 4 1111 1111 1111 [removed] 5 0100 1000 1100

2 points

Question 14

1.

An attribute of randomness that can be used to determine the strength of a password is known as?

 [removed] 1 Entropy [removed] 2 Diffusion [removed] 3 Confusion [removed] 4 Maturation [removed] 5 Reversability

2 points

Question 15

1.

The standard that guides Security Architecture for OSI:

 [removed] 1 X.800 [removed] 2 X.504 [removed] 3 FIPS Pub 200 [removed] 4 X.895 Security Standard [removed] 5 RFC 2828

2 points

Question 16

1.

A root digital certificate is typically issued by who?

 [removed] 1 Registration authority [removed] 2 Certificate authority [removed] 3 Any individual [removed] 4 X800 standards commitee [removed] 5 A secure directory system that uses LDAP

2 points

Question 17

1.

The number of different keys used in symmetric encryption is Blank 1[removed]

2 points

Question 18

1.

Select the correct answer. The Diffie Hellman algorithm is used for what?

 [removed] 1 Public key encryption. [removed] 2 Symmetric encryption [removed] 3 Message Authentication [removed] 4 Key Exchange [removed] 5 Message digest generation

2 points

Question 19

1.

When creating a digital envelope which of the following steps are done.

A. The message is encrypted using a one time random symmetric key

B. The one time random symmetric key is encrypted by using the receivers private key

C. The one time random key is made a public key

D. The message is encrypted by using a one time random asymmetric key

E. The one time random symmetric key is encrypted with the receivers public key

 [removed] 1 A, E [removed] 2 A, C [removed] 3 B, E [removed] 4 C, D [removed] 5 A, D

2 points

Question 20

1.

Select the best answer that defines Security Risk

 [removed] 1 Threat of attack coupled with security breach [removed] 2 Threat of attack and vulnerability to attack [removed] 3 Vulnerability to attack coupled with an active attack [removed] 4 Threat of active and passive attack

2 points

Question 21

1.

Using a Playfair cipher what is the plaintext for the following ciphertext. RNNEQLDKPCNRMI The keyword you should use is “MONEY”. You are being asked to decrypt this message. Blank 1[removed]

2 points

Question 22

1.

With a symmetric block cipher the relationship with key size, security and performance is what?

A. The larger the key the more secure the algorithm

B. The larger the key size the slower encryption/decryption performance.

C. The larger the key the easier to perform cryptanalysis

D. The smaller the key the more secure the encryption/decryption

E. The larger the key the faster the encryption/decryption performance.

 [removed] 1 A, C [removed] 2 A, B [removed] 3 A, B, C [removed] 4 C, D [removed] 5 B, C

2 points

Question 23

1.

A Security Mechanism is an implementation of a specific program, process or device that is designed to detect, prevent, or recover from a security attack.

[removed]True

[removed]False

2 points

Question 24

1.

Match the cryptology mechanism with what type it is.

 DES AES Diffie Hellman Cipher block chaining Cipher feedback RC4 Electronic codebook SHA1 3DES MD5

 A. Symmetric stream encryption B. Mode of operation C. Hashing algorithm D. Key exchange E. Symmetric block encryption

7 points

Question 25

1.

A Security Service protects against specific threats according to the categorization of security threats in the X.503 architecture.

[removed]True

[removed]False

2 points

Question 26

1.

Assuming only asymmetric encryption is being used for communication between two parties. How many different keys are in play for sending one message from person A to person B? Assume person B reads the message.

 [removed] 1 2 [removed] 2 1 [removed] 3 Cannot determine [removed] 4 At least three

2 points

Question 27

1.

Select the best answer. If the sender uses the recipients public key to encrypt a message what functionality is provided:

 [removed] 1 Message integrity [removed] 2 Message confidentiality [removed] 3 Message authentication [removed] 4 Message authentication and message confidentiality [removed] 5 none of the choices

2 points

Question 28

1.

Using a rail fence cipher with a depth of 3 encrypt the following message:

The party is at Fenway in October Blank 1[removed]

2 points

Question 29

1.

The sender of the message in Digital signature encrypts the message digest using what?

 [removed] 1 The secret key. [removed] 2 Receivers public key. [removed] 3 Senders private key. [removed] 4 Symmetric key. [removed] 5 MAC value.

2 points

Question 30

1.

A digital certificate is what?

 [removed] 1 A notarized document certifying your identity. [removed] 2 A mail message sent with a Digital Signature from any third party that certifies the identity of a person or an entity. [removed] 3 Secret keys (among other information) used for symmetric encryption. [removed] 4 Public key (among other information) used for asymmetric encryption. [removed] 5 A mail message from a registration authority (RA).

2 points

Question 31

1.

Prime numbers are sometimes used to construct private and public key pairs.

[removed]True

[removed]False

2 points

Question 32

1.

The key benefit of the Feistel Cipher is:

 [removed] 1 The same algorithm can be used for encryption and decryption. [removed] 2 There are always 16 rounds. [removed] 3 There can be more then 16 rounds. [removed] 4 The algorithm is very difficult to analyze. [removed] 5 The algorithm can use different block sizes.

2 points

Question 33

1.

Match the specific attack with the type of attack it is.

 Disruption of Service Eavesdropping Masquerade Traffic Analysis Modification of data Replay

6 points

Question 34

1.

Match the Feistel mechanism with the corresponding attribute. Use each option once. Select the best choice.

 A. S (substitution) Box B. Uses P Boxes and S Boxes C. Boolean operation combines keys with data D. Derived from overall key E. P (permutation) Box

5 points

Question 35

1.

Select the best answer. If the senders private key is used to encrypt a message what functionality is provided:

 [removed] 1 Message integrity and confidentiality [removed] 2 Message confidentiality [removed] 3 Message authentication [removed] 4 Message authentication and message integrity [removed] 5 Message authentication and message confidentiality

2 points

Question 36

1.

Match the specific authentication technique with general type of authentication it is.

 A. Encryption authentication B. Token authentication C. Static biometric authentication D. Active biometric authentication E. Something a person knows

5 points

Question 37

1.

The Diffie-Hellman key exchange is vulnerable to a Blank 1[removed] attack.

2 points

Question 38

1.

Using a Playfair cipher encrypt the following plaintext: THE CAR IS HERE Use HELLO as the keyword to set up the matrix. Show the answer in digraph form. Blank 1[removed]

2 points

Question 39

1.

The CIA acronym refers to which of the following:

 [removed] 1 Central Intelligence Association [removed] 2 Confidentiality, Integrity, Availability [removed] 3 Communication, Integrity, Accessibility [removed] 4 Cipher, Intelligence, Availability [removed] 5 None of the above

2 points

Question 40

1.

A secret key used for generating a message authentication code (MAC) should only be shared between the sender and receiver of a message.

[removed]True

[removed]False

2 points

Save and Submit