160+ Cryptography and Network Security (CNS) Solved MCQs

101.

In Elgamal cryptosystem, given the prime p=31,What is the respective plaintext character for C = (27, 20)?

A. h
B. l
C. o
D. m
Answer» A. h
102.

How many real and imaginary roots does the equation y2=x3-1 have

A. 2 real, 1 imaginary
B. all real
C. all imaginary
D. 2 imaginary, 1 real
Answer» D. 2 imaginary, 1 real
103.

“In ECC, the inverse of point P =(x1, y1) is Q = (-x1, y1). “

A. true
B. false
Answer» B. false
104.

In the elliptic curve group defined by y2= x3- 17x + 16 over real numbers, what is P + Q if P = (0,-4) and Q = (1, 0)?

A. (15, -56)
B. (-23, -43)
C. (69, 26)
D. (12, -86)
Answer» A. (15, -56)
105.

How many real and imaginary roots does the equation y2=x3-4x have

A. 2 real, 1 imaginary
B. all real
C. all imaginary
D. 2 imaginary, 1 real
Answer» B. all real
106.

In the elliptic curve group defined by y2= x3- 17x + 16 over real numbers, what is 2P if P = (4, 3.464)

A. (12.022, -39.362)
B. (32.022, 42.249)
C. (11.694, -43.723)
D. (43.022, 39.362)
Answer» A. (12.022, -39.362)
107.

In public key cryptosystem             keys are used for encryption and decryption.

A. same
B. different
C. encryption keys
D. none of the mentioned
Answer» B. different
108.

PGP system uses

A. private key system
B. public key system
C. private & public key system
D. none of the mentioned
Answer» C. private & public key system
109.

Knapsack problem can be solved by

A. public key cryptosystem
B. public key system
C. private & public key system
D. none of the mentioned
Answer» A. public key cryptosystem
110.

Merkle hellman is a symmetric cryptosystem.

A. true
B. false
Answer» B. false
111.

In public key cryptosystem which is kept as public?

A. encryption keys
B. decryption keys
C. encryption & decryption keys
D. none of the mentioned
Answer» A. encryption keys
112.

A cryptographic hash function has variable output length.

A. true
B. false
Answer» B. false
113.

In a trapdoor function, the functions are easy to go in

A. one direction
B. two directions
C. all directions
D. none of the mentioned
Answer» A. one direction
114.

Which algorithm can be used to sign a message?

A. public key algorithm
B. private key algorith
C. public & private key algorithm
D. none of the mentioned
Answer» A. public key algorithm
115.

In this Merkle Hellman method same key is used for encryption and decryption.

A. true
B. false
Answer» B. false
116.

A set of numbers is called as super increasing if

A. each element is greater than previous element
B. each element greater than sum of all the previous elements
C. each element greater than the average of all elements
D. each element lesser than the sum of all the elements
Answer» B. each element greater than sum of all the previous elements
117.

There are         major ways of stealing email information.

A. 2
B. 3
C. 4
D. 5
Answer» B. 3
118.

Which of them is not a major way of stealing email information?

A. stealing cookies
B. reverse engineering
C. password phishing
D. social engineering
Answer» B. reverse engineering
119.

          is the method for keeping sensitive information in email communication & accounts secure against unofficial access, loss, or compromise.

A. email security
B. email hacking
C. email protection
D. email safeguarding
Answer» A. email security
120.

            is a famous technological medium for the spread of malware, facing problems of spam, & phishing attacks.

A. cloud
B. pen drive
C. website
D. email
Answer» D. email
121.

Fraudulent email messages are some fake email messages that seem legitimate which asks for your confidential bank details such as              details and passwords.

A. credit card, antivirus name
B. credit card, login id
C. cell phone, antivirus name
D. car model, account id
Answer» B. credit card, login id
122.

Unsolicited Bulk E-mails (UBI) are called

A. sms
B. mms
C. spam emails
D. malicious emails
Answer» C. spam emails
123.

Using email hacking illicit hackers can send & spread           virus               and spam emails.

A. trojans, redirected malicious urls
B. antivirus, patches
C. cracked software, redirected malicious urls
D. malware, security patches
Answer» A. trojans, redirected malicious urls
124.

            is the technique used for tricking users to disclose their username and passwords through fake pages.

A. social engineering
B. phishing
C. cookie stealing
D. banner grabbing
Answer» B. phishing
125.

Which of them is an example of grabbing email information?

A. cookie stealing
B. reverse engineering
C. port scanning
D. banner grabbing
Answer» A. cookie stealing
126.

Which of the following is a non-technical type of intrusion or attack technique?

A. reverse engineering
B. malware analysis
C. social engineering
D. malware writing
Answer» C. social engineering
127.

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.

A. memory
B. quarantine
C. cookies
D. hard drive
Answer» C. cookies
128.

The stored cookie which contains all your personal data about that website can be stolen away by             using or trojans.

A. attackers, malware
B. hackers, antivirus
C. penetration testers, malware
D. penetration testers, virus
Answer» A. attackers, malware
129.

If a website uses a cookie, or a browser contains the cookie, then every time you visit that website, the browser transfers the cookie to that website.

A. true
B. false
Answer» A. true
130.

Which of them is not a proper method for email security?

A. use strong password
B. use email encryption
C. spam filters and malware scanners
D. click on unknown links to explore
Answer» D. click on unknown links to explore
131.

What are email security services?

A. confidentiality
B. authentication
C. non-repudation of origin
D. all of the above
Answer» D. all of the above
132.

PGP security system uses

A. public key cryptosystem
B. private key cryptosystem
C. public & private key cryptosystem
D. none of the mentioned
Answer» C. public & private key cryptosystem
133.

What is the key size allowed in PGP?

A. 1024-1056
B. 1024-4056
C. 1024-4096
D. 1024-2048
Answer» C. 1024-4096
134.

Who created PGP?

A. phil zimmermann
B. tim berners-lee
C. marc andreessen
D. ken thompson
Answer» A. phil zimmermann
135.

What is the PGP stand for?

A. permuted gap permission
B. permuted great privacy
C. pretty good privacy
D. none of the mentioned
Answer» C. pretty good privacy
136.

PGP makes use of which cryptographic algorithm?

A. des
B. aes
C. rsa
D. rabin
Answer» C. rsa
137.

PGP offers        block ciphers for message encryption?

A. triple-des
B. cast
C. idea
D. all of the above
Answer» D. all of the above
138.

S/MIME stands for          .

A. standard multipurpose internet mail extensions.
B. secure multipurpose internet mail extensions.
C. secure multipurpose international mail extensions
D. standard multipurpose international mail extensions.
Answer» B. secure multipurpose internet mail extensions.
139.

is used for hiding the payment information from the merchant.

A. set.
B. ssl.
C. shttp
D. tsp
Answer» A. set.
140.

The cryptography algorithms used in S/MIME are .

A. idea.
B. rc4
C. rsa,des-3
D. rc5
Answer» C. rsa,des-3
141.

In S/MIME,MLA stands for .

A. mailing list agent.
B. multipurpose list agent.
C. mail lock agent.
D. message link agen
Answer» A. mailing list agent.
142.

Which component is included in IP security?

A. authentication header (ah)
B. encapsulating security payload (esp)
C. internet key exchange (ike)
D. all of the mentioned
Answer» A. authentication header (ah)
143.

WPA2 is used for security in

A. ethernet
B. bluetooth
C. wi-fi
D. email
Answer» C. wi-fi
144.

An attempt to make a computer resource unavailable to its intended users is called

A. denial-of-service attack
B. virus attack
C. worms attack
D. botnet process
Answer» A. denial-of-service attack
145.

PGP is used in

A. browser security
B. email security
C. ftp security
D. wifi security
Answer» B. email security
146.

In tunnel mode, IPSec protects the

A. entire ip packet
B. ip header
C. ip payload
D. ip trailer
Answer» A. entire ip packet
147.

IPSec is designed to provide security at the

A. transport layer
B. network layer
C. application layer
D. session layer
Answer» B. network layer
148.

Which of the following is not a strong security protocol?

A. https
B. ssl
C. smtp
D. sftp
Answer» C. smtp
149.

SSL primarily focuses on

A. integrity and authenticity
B. integrity and non-repudiation
C. authenticity and privacy
D. confidentiality and integrity
Answer» A. integrity and authenticity
150.

Why did SSL certificate require in HTTP?

A. for making security weak
B. for making information move faster
C. for encrypted data sent over http protocol
D. for sending and receiving emails unencrypted
Answer» C. for encrypted data sent over http protocol
151.

SFTP is abbreviated as           

A. secure file transfer protocol
B. secured file transfer protocol
C. secure folder transfer protocol
D. secure file transferring protoco
Answer» A. secure file transfer protocol
152.

       mointors user activity on internet and transmit that information in the background to someone else

A. malware
B. spyware
C. adware
D. none of these
Answer» B. spyware
153.

Firewall is type of------

A. virus
B. security threat
C. worm
D. none of these
Answer» D. none of these
154.

The full form of Malware is

A. malfunctioned software
B. multipurpose software
C. malicious software
D. malfunctioning of security
Answer» C. malicious software
155.

There are types of computer virus.

A. 5
B. 7
C. 10
D. 12
Answer» C. 10
156.

A computer           is a malicious code which self-replicates by copying itself to other programs.

A. program
B. virus
C. application
D. worm
Answer» B. virus
157.

Which of them is not an ideal way of spreading the virus?

A. infected website
B. e-mails
C. official antivirus cds
D. usbs
Answer» C. official antivirus cds
158.

                 is the kind of firewall is connected between the device and the network connecting to internet.

A. hardware firewall
B. software firewall
C. stateful inspection firewall
D. microsoft firewall
Answer» A. hardware firewall
159.

Which of the following is not a software firewall?

A. windows firewall
B. outpost firewall pro
C. endian firewall
D. linksys firewall
Answer» D. linksys firewall
160.

Firewall examines each           that are entering or leaving the internal network

A. emails users
B. updates
C. connections
D. data packets
Answer» D. data packets
161.

A firewall protects which of the following attacks?

A. phishing
B. dumpster diving
C. denial of service
D. shoulder surfing
Answer» C. denial of service
162.

Packet filtering firewalls are deployed on

A. routers
B. switches
C. hubs
D. repeaters
Answer» A. routers
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