BVRIT HYDERABAD College of Engineering for Women

(Approved by AICTE | Affiliated to JNTUH | Accredited by NAAC with Grade ‘A’ & NBA for CSE, ECE, EEE, & IT)
Bachupally, Hyderabad-090
-

Department of Computer Science & Engineering

Multiple Choice Questions
Year : IV Semester : I Regulations : R18
Course
Course Code : CS701PC : Cryptography and Network Security
Name
Academic
: 2021-22
Year

Faculty
Dr. Venkatesh B, Assoc. Prof
Name(s) :
Ms. T Durga Devi,& Ms. Preethi V , Asst. Prof
UNIT-V
E-Mail Security: Pretty Good Privacy, S/MIME IP Security: IP Security overview, IP
Security architecture, Authentication Header, Encapsulating security payload,
Combining security associations, Internet Key Exchange
Case Studies on Cryptography and security: Secure Multiparty Calculation, Virtual
Elections, Single sign On, Secure Inter-branch Payment Transactions, Cross site
Scripting Vulnerability.
S.No. Question Answer
Pretty good privacy (PGP) security system uses
a) Public key cryptosystem
1. b) Private key cryptosystem c
c) Public & Private key cryptosystem
d) None of the mentioned
Public key cryptosystem is used for the encryption of
a) Messages
2. b) Session key b
c) Session key & Messages
d) None of the mentioned User Interface
Public key cryptosystem is used for the encryption of
a) Messages
3. b) Session key d
c) Session key & Messages
d) None of the mentioned
What is the key size allowed in PGP?
a) 1024-1056
4. b) 1024-4056 c
c) 1024-4096
d) 1024-2048
Which should be used first to decrypt?
a) Public key
5. b) Private key b
c) Public & Private key
d) None of the mentioned
 One security protocol for the e-mail system is .
a) IPSec
6. b) SSL c
c) PGP
d) none of the above
uses the idea of certificate trust levels.
a) X509
7. b) PGP b
c) KDC
d) none of the above
provides privacy, integrity, and authentication in e-mail.
a) IPSec
8. b) SSL c
c) PGP
d) none of the above
, there can be multiple paths from fully or partially trusted
authorities.
a) X509
9. b
b) PGP
c) KDC
d) none of the above
In , the cryptographic algorithms and secrets are sent with
the message.
a) IPSec
10. d
b) SSL
c) TLS
d) PGP
was invented by Phil Zimmerman.
a) IPSec
11. b) SSL c
c) PGP
d) none of the above
SMTP stands for
a) Short Mail Transmission Protocol
12. b) Small Mail Transmission Protocol d
c) Server Mail Transfer Protocol
d) Simple Mail Transfer Protocol
Data compression includes
a) Removal of redundant character
b) Uniform distribution of characters
13. c
c) Removal of redundant character & Uniform distribution of
characters
d) None of the mentioned
Which algorithm is used for public key encryption?
a) RSA
14. b) Diffie-Hellman c
c) RSA & Diffie-Hellman
d) None of the mentioned
IPsec is designed to provide the security at the
a) Transport layer
15. b) Network layer b
c) Application layer
d) Session layer
Which component is included in IP security?
16. a) Authentication Header (AH) d
b) Encapsulating Security Payload (ESP)
 c) Internet key Exchange (IKE)
d) All of the mentioned
IPsec services are available in Layer.
a) Application
17. b) Data link c
c) Network
d) Transport
The Authentication Header (AH) , part of IPsec, provides which of
the following security function?
a) Source authentication
18. d
b) Data Integrity
c) Data confidentiality
d) Source authentication and data integrity
The mode of IPsec, take the whole IP packet to form secure
communication between two gateways
a) Transport
19. b
b) Tunnel
c) Either (a) or (b)
d) Both (a) and (b)
Encapsulating Security Payload (ESP) belongs to which Internet
Security Protocol?
a) Secure Socket Layer Protocol
20. b
b) Secure IP Protocol
c) Secure Http Protocol
d) Transport Layer Security Protocol
The secret key between members needs to be created as a
key when two members contact KDC.
a) public
21. b
b) session
c) complimentary
d) none of the abov
A(n) is a trusted third party that assigns a symmetric key to
two parties.
a) KDC
22. a
b) CA
c) KDD
d) none of the above
operates in the transport mode or the tunnel mode.
a) IPSec
23. b) SSL a
c) PGP
d) none of the above
IKE creates SAs for .
a) SSL
24. b) PGP c
c) IPSec
d) VP
provides either authentication or encryption, or both, for
packets at the IP level.
a) AH
25. b
b) ESP
c) PGP
d) SSL
One security protocol for the e-mail system is .
26. a) IPSec c
b) SSL
 c) PGP
d) none of the above
IPSec defines two protocols: and .
a) AH; SSL
27. b) PGP; ESP c
c) AH; ESP
d) all of the above
is a collection of protocols designed by the IETF (Internet
Engineering Task Force) to provide security for a packet at the
network level.
28. a) IPSec a
b) SSL
c) PGP
d) none of the above
In PGP, to exchange e-mail messages, a user needs a ring of
keys.
a) secret
29. b
b) public
c) either (a) or (b)
d) both (a) and (b)
Which of the following transport layer protocols is used to support
electronic mail?
a) SMTP
30. a
b) IP
c) TCP
d) UDP
MIME stands for
a) Multipurpose Internet Mail Extensions
31. b) Multipurpose Internet Mail Email a
c) Multipurpose International Mail Entity
d) Multipurpose International Mail End
In architecture of e-mail, we can have
a) 2 Scenarios
32. b) 3 Scenarios d
c) 4 Scenarios
d) 6 Scenarios
Mail access starts with client when user needs to download e-mail
from the
a) Mail Box
33. a
b) Mail Server
c) Mail Host
d) Internet
When sender and receiver of an e-mail are on same system, we need
only two
a) IP
34. d
b) Domain
c) Servers
d) User Agents
What "layer" of an e-mail message should you consider when
35. evaluating e-mail security? d
a. TCP/IP
 b. SMTP
c. Body
d. All of the above
Why isn't S/MIME the perfect solution to e-mail security?
a. It provides authentication and privacy, but not integrity
checking.
36. b. It provides authentication and integrity checking, but not c
privacy.
c. It has scalability problems.
d. What are you talking about? It is the perfect solution.
What are the two most common errors associated with keyword
searching across e-mail messages?
a. Ignoring the subject line
37. c
b. Ignoring case significance
c. Improper word stemming
d. Ignoring alphanumeric characters
…………… is to protect data and passwords.
a) Encryption
38. b) Authentication a
c) Authorization
d) Non-repudiation
MAC stands for
a. Message access code
39. b. Message authentication code b
c. both a and b
d. none
OAKLEY is the refinement of
a. RSA
40. b. Diffie Hellmann b
c. DES
d. AES
ESP stands for
a. escape pay load
41. b. encapsulating security payload b
c. both
d. none
The payload length in ISAKMP in bytes is
a. 2
42. b. 3 a
c. 4
d. 5
The payload length in AH in bits is
a. 2
43. b. 3 d
c.6
d. 8
PGP stands for
a. pretty good privacy
44. b. Pretty god privacy a
c. Permanent good privacy
d. none
S/MIME stands for
a. Secure/Multipurpose Internet Mail Extension
45. b. Secure/Multipurpose Internet Message Extension a
c. Secure/Multiple Internet Mail Extension
d. none
 RFC stands for
a. Request for comment
46. b. Request for common Data a
c. Reply for comment
d. none
DOI stands for
a. Dummy of Interpretation
47. b. Domain of Interpretation b
c. Domain of Interpersonal
d. none
SPI stands for
a. Secret Parameters Index
48. b. Security Parameters Interconnection c
c. Security Parameters Index
d. none
SA stands for
a. Security Associations
49. b. Secret Associations a
c. Security Access
d. none
MTU stands for
a. maximum transfer unit
50. b. maximum transmission universe b
c. maximum transmission unit
d. none
PGP makes use of which cryptographic algorithm?
a) DES
b) AES
51. c
c) RSA
d) Rabin
Explanation: PGP recommends the use of RSA.
USENET is related to which of the following Public Key distribution
schemes?
a) Public-Key Certificates
b) Public announcements
c) Publicly available directories
52. b
d) Public-Key authority

Explanation: Many PGP users append their public key to messages

that they send to public forums, such as USENET and Internet
mailing lists.
Publicly Available directory is more secure than which other
system?
a) Public-Key Certificates
b) Public announcements
53. b
c) Public-Key authority
d) None of the mentioned
Explanation: Publicly Available directory is more secure than Public
announcements.
Extensions were added in which version?
a) 1
b) 2
54. c) 3 c
d) 4
Explanation: Extensions to the X.509 certificates were added in
version 3.
 “Conveys any desired X.500 directory attribute values for the
subject of this certificate.” Which Extension among the
following does this refer to?
a) Subject alternative name
b) Issuer Alternative name
55. c) Subject directory attributes c
d) None of the mentioned
Explanation: The Subject directory attributes has the function of
conveying any desired X.500directory attribute values for the
subject of this certificate.”
Certificates generated by X that are the certificates of other CAs are
Reverse Certificates.
a) True
56. a
b) False
Explanation: The statement is true. Certificates of X generated by
other CAs are forwardcertificates.
It is desirable to revoke a certificate before it expires because
a) the user is no longer certified by this CA
b) the CA’s certificate is assumed to be compromised
57. c) the user’s private key is assumed to be compromised d
d) all of the mentioned
Explanation: All of the options are true with regard to revocation of
a certificate
CRL stands for
a) Cipher Reusable List
b) Certificate Revocation Language
58. c
c) Certificate Revocation List
d) Certificate Resolution Language
Explanation: CRL stands for Certificate Revocation List.
Which of the following is not a part of an Extension?
a) Extension Identifier
b) Extension value
59. c) Criticality Indicator d
d) All of the mentioned constitute the Extension
Explanation: Extension Identifier, Extension value and the
Criticality Indicator all constitue the Extension header.
The criticality indicator indicates whether an extension can be
safely ignored.
60. a) True a
b) False
Explanation: The statement is true.
The subject unique identifier of the X.509 certificates was added in
which version?
a) 1
b) 2
61. b
c) 3
d) 4
Explanation: The subject unique identifier was added in the 2nd
version.
Which of the following is not an element/field of the X.509
certificates?
a) Issuer Name
62. b
b) Serial Modifier
c) Issuer unique Identifier
d) Signature
 Explanation: Serial Modifier is not an element/field of the X.509
certificates.
Suppose that A has obtained a certificate from certification
authority X1 and B has obtained
certificate authority from CA X2. A can use a chain of
certificates to obtain B’s public key. Innotation of X.509, this
chain is represented in the correct order as –
63. c
a) X2 X1 X1 B
b) X1 X1 X2 A
c) X1 X2 X2 B
d) X1 X2 X2 A
Explanation: The correct representation would be X1 X2 X2 B.
Larger networks would prefer a full decentralization.
a) True
64. b) False b
Explanation: Full decentralization is not practical for larger
networks as there would be too many connections.
Which of these is not a type of session key?
a) PIN-encrypting key
b) File-encrypting key
65. c
c) Session encrypting key
d) Data encrypting key
Explanation: Data, PIN and File are the different session keys.
Which session key is used for electronic funds transfer and point of
sale applications?
a) Data-encrypting key
b) File-encrypting key
66. c
c) PIN-encrypting key
d) None of the mentioned
Explanation: PIN-encrypting key is the session key which is used for
electronic funds transfer andpoint of sale applications.
Sometimes a simple tag is introduced along with the session key.
This tag has 8 bits. Which of thefollowing options is wrong?
a) One bit indicates whether the key is a session key or a master
key
67. b) One bit indicates whether the key can be used for encryption c
c) Three bit indicates whether the key can be used for decryption
d) Remaining bits are for future use
Explanation: One bit indicates whether the key can be used for
decryption.
“Meet in the middle attack” and “man in the middle attack” are the
same.
a) True
68. c
b) False
Explanation: Man is the middle attack is different from meet in the
middle attack.
Which of the following is required to find the session key?
i) Control Vector
69. ii) Master Key d
iii) Encrypted session Key
a) i)
 b) i) and ii)
c) i) and iii)
d) i) ii) and iii)
Explanation: We require all three to find the session key.
Which is the correct representation for session key recovery for the
plain text?
a) D ([Km XOR H], E([Km XOR H], Ks)
b) D([Km XOR H],Ks)
70. c) D ([Km XOR H], E([Km XOR H]) a
d) None of the mentioned
Explanation: The correct representation is D([Km XOR H], E([Km
XOR H], Ks), to recover the session key.
“Meet in the middle attack” is an attack
a) where the timing required for the attack via brute force is
drastically reduced
b) where the adversary uses 2 or more machines to decrypt thus
trying to reduce the time
c) where messages are intercepted and then either relayed or
71. c
substituted with another message
d) where cryptanalysis takes lesser time than the brute force
decryption
Explanation: “Meet in the middle attack” is an attack where
messages are intercepted and then either relayed or substituted with
another message.
Hash Value = H = h(CV) Key Input = Km XOR H Ciphertext =
E([Km XOR H],Ks) What is CV here?
a) Cipher vector
72. b) Current vector c
c) Control vector
d) None of the mentioned
Explanation: CV is known as Control Vector.
There are major ways of stealing email information. b
a) 2
73. b) 3
c) 4
d) 5
Which of them is not a major way of stealing email b
information?
a) Stealing cookies
74.
b) Reverse Engineering
c) Password Phishing
d) Social Engineering
is the method for keeping sensitive information in
email communication & accounts secure against unofficial
access, loss, or compromise. a
75. a) Email security
b) Email hacking
c) Email protection
d) Email safeguarding
is a famous technological medium for the spread of
76. malware, facing problems of spam, & phishing attacks.
d
 a) Cloud
b) Pen drive
c) Website
d) Email

Fraudulent email messages are some fake email messages

that seem legitimate which asks for your confidential bank
details such as details and passwords. b
77. a) credit card, antivirus name
b) credit card, login ID
c) cell phone, antivirus name
d) car model, account ID
Unsolicited Bulk E-mails (UBI) are called c
a) SMS
78. b) MMS
c) Spam emails
d) Malicious emails

Using email hacking illicit hackers can send & spread virus
and spam emails. a
a) trojans, redirected malicious URLs
79. b) antivirus, patches
c) cracked software, redirected malicious URLs
d) malware, security patches
is the technique used for tricking users to disclose
their username and passwords through fake pages? b
a) Social Engineering
80. b) Phishing
c) Cookie Stealing
d) Banner Grabbing

Which of them is an example of grabbing email information? a

a) Cookie stealing
81. b) Reverse engineering
c) Port scanning
d) Banner grabbing
Which of the following is a non-technical type of intrusion or c
attack technique?
a) Reverse Engineering
82. b) Malware Analysis
c) Social Engineering
d) Malware Writing

If the data stored in the is not encrypted, then after

cookie stealing, attackers can see information such as
username and password stored by the cookie. c
83. a) memory
b) quarantine
c) cookies
d) hard drive
The stored cookie which contains all your personal data
84. about that website can be stolen away by using or trojans.
 a) attackers, malware a
b) hackers, antivirus
c) penetration testers, malware
d) penetration testers, virus

If a website uses a cookie, or a browser contains the cookie,

then every time you visit that website, the browser transfers
a
85. the cookie to that website.
a) True
b) FALSE
Which of them is not a proper method for email security? d
a) Use Strong password
86. b) Use email Encryption
c) Spam filters and malware scanners
d) Click on unknown links to explore
What are email security services? d
a) Confidentiality
b) Authentication
87.
c) Non-repudiation of origin
d) All of the above

PGP security system uses c

a) Public key cryptosystem
88. b) Private key cryptosystem
c) Public & Private key cryptosystem
d) None of the mentioned
What is the key size allowed in PGP? c
a) 1024-1056
89. b) 1024-4056
c) 1024-4096
d) 1024-2048
Who created PGP? a
a) Phil Zimmermann
90.
b) Tim Berners-Lee
c) Marc Andreessen
d) Ken Thompson
What is the PGP stand for? c
a) Permuted Gap Permission
b) Permuted Great Privacy
91.
c) Pretty Good Privacy
d) None of the mentioned
PGP makes use of which cryptographic algorithm? c
a) DES
92. b) AES
c) RSA
d) Rabin
PGP offers block ciphers for message encryption? d
a) Triple-DES
93. b) CAST
c) IDEA
d) All of the above
 S/MIME stands for . b
a) standard multipurpose internet mail extensions.
94. b) secure multipurpose internet mail extensions.
c) secure multipurpose international mail extensions
d) standard multipurpose international mail extensions.

is used for hiding the payment information from the a

merchant.
a) SET.
95. b) SSL.
c) SHTTP
d) TSP

The cryptography algorithms used in S/MIME are . c

a) IDEA.
96. b) RC4
c) RSA, DES-3
d) RC5
In S/MIME, MLA stands for . a
a) mailing list agent.
b) multipurpose list agent.
97.
c) mail lock agent.
d) message link agent
Which component is included in IP security? a
a) Authentication Header (AH)
b) Encapsulating Security Payload (ESP)
98.
c) Internet key Exchange (IKE)
d) All of the mentioned
WPA2 is used for security in c
a) Ethernet
99. b) Bluetooth
c) Wi-Fi
d) Email
An attempt to make a computer resource unavailable to its a
intended users is called
a) Denial-of-service attack
100.
b) Virus attack
c) Worms attack
d) Botnet process