CUSTOMER_CODE
SMUDE
DIVISION_CODE
SMUDE
EVENT_CODE
OCTOBER15
ASSESSMENT_CODE BT0088_OCTOBER15
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
12783
QUESTION_TEXT
Explain SET features and components.
SCHEME OF
EVALUATION
SET incorporates important features needed for secure credit card
transaction over the Internet:
*Confidentiality of information: Cardholder account and payment
information is secured as it traverses across the network. DES is used to
provide confidentiality.
*Integrity of Data: Payment information sent from cardholders to
merchants includes order information, personal data, and payment
instructions. SET guarantees that these message contents are not altered
in transit. RSA digital signatures, using SHA-1 hash codes, sometimes
HMAC, using SHA-1.
*Cardholder account authentication: SET enables merchants to verify
that a cardholder is legitimate user of a valid card account number. SET
uses digital certificates with RSA signatures for this purpose.
*Merchant Authentication: SET enables cardholders to verify that a
merchant has a relationship with a financial institution allowing it to
accept payment cards. SET uses Digital certificates with RSA signatures
for this purpose.
(1 mark each=4 marks)
Components:
*Cardholder: A cardholder is an authorized holder of a payment card
that has been issued by issuer.
*Merchant: A merchant is a person or organization with goods or
services to sell to the cardholder.
*Issuer: This is a financial institution such as bank that provides the
cardholder with the payment card.
*Acquirer: This is a financial institution that establishes an account with
a merchant and processes payment card authorization and payments.
*Payment Gateway: This is a function operated by the acquirer or a
designated third party that processes merchant payment messages.
*Certificate Authority: This is an entity that is trusted to issue X.509v3
public key certificates for cardholders, merchants, and payment
gateways.(1 mark each= 6 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
72789
QUESTION_TEXT
Explain the characteristics of following malicious codes:
a. Virus
b. Worm
c. Trojan Horse
d. Trap door
e. Logic bomb
SCHEME OF
EVALUATION
a. Virus: A virus is a program that can spread the malicious code to
other non malicious programs by modifying them. A virus can be either
transient or resident. A transient virus has a life that depends on the life
of its host; A resident virus locates itself in memory.
b. Worm: A worm is a program that spreads copies of itself through a
network. The worm spreads copies of itself as a stand-alone program.
c. Trojan horse: It is malicious code that, in addition to its primary
effect, has a second, nonobvious malicious effect. Contains unexpected,
additional functionality.
d. Trap door: it is feature in a program by which some one can access
the program other than by the obvious, direct call perhaps with special
privileges. The trapdoor could be intentional, for maintenance
purposes, or it could be an illicit way for the implementer to wipe out
any record of a crime.
e. Logic bomb: it is a class of malicious code that detonates or goes
off when a specified condition occurs. (2 marks each)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
72791
QUESTION_TEXT
Explain how cryptanalyst uses different information to break the
cipher?
SCHEME OF
EVALUATION
a. Ciphertext only: The cryptanalyst decrypt messages based on
probabilities, distributions, and characteristics of the available
ciphertext, plus publicly available knowledge.
b. Full or partial plaintext: the analyst may be fortunate to have a
sample message and its decipherment. In these cases, the analyst can
use what is called a probable plaintext analysis. After doing part of the
decryption, the analyst may find places where the known message fits
with the deciphered parts, thereby giving more clues about the total
translation.
c. Ciphertext of any plaintext: the analyst might have infiltrated the
sender’s transmission process so as to be able to cause messages to be
encrypted and sent at will. This attack is called a chosen plaintext
attack. For instance, the analyst may be able to insert records into a
database and observe the change in statistics after the insertions.
Linear programming some times enables such an analyst to infer data
that should be kept confidential in the database. This attack is very
favorable to the analyst.
d. Algorithm and Ciphertext: the analyst may have both the
encryption algorithm and the ciphertext. In a chosen plaintext attack,
the analyst can run the algorithm on massive amounts of plaintext to
find one plaintext message that encrypt as the ciphertext. This
approach fails if two or more distinct keys can produce the same
ciphertext as the result of encrypting meaningful plaintext.
e. Ciphertext and Plaintext: the cryptanalyst may lucky enough to
have some pairs of plaintext and matching ciphertext. Then, the game is
to deduce the key by which those pairs were encrypted so that the
same key can be used in cases in which the analyst has only the
ciphertext. (2 marks each)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
72795
QUESTION_TEXT
Write a note on
i. Cryptographic Hash function
ii. Digital Signature
Short note on:
SCHEME OF EVALUATION i. Cryptographic Hash function
ii. Digital Signature
5 marks
5 marks
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
118693
QUESTION_TEXT
Give the advantages and disadvantages of different types of
Encryption System.
Ans:
Stream Encryption system:
SCHEME OF
EVALUATION
Advantages:
1.
Speed of transformation–1M
2.
Low error propagation–1M
Disadvantages:
1.
Susceptibility to malicious insertions and modifications–2M
2.
Low diffusion–2M
Block Encryption Algorithms advantages:
1.
High diffusion–1M
2.
Immunity to insertion of symbols–1M
Disadvantages:
1.
Slowness of encryption–1M
2.
Error Propagation–1M
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
118698
QUESTION_TEXT
Explain the different characteristics of networks.
Ans: Each point needs to be explained
a.
Anonymit:1M
b.
Automation: 2M
c.
Opaqueness:3M
d.
Distance: 2M
e.
Routing diversity:2M
SCHEME OF EVALUATION