ITN 262 - FINAL EXAM QUESTIONS WITH
CORRECT ANSWERS.
The phrases below describe fields in an IP packet. Match the IP packet field with its
description.
Fragment field
TTL field
Type field
IP checksum field
Source IP address field
Destination IP address field
Data field
-Counts the number of times a packet passes through a router
-Manages the fragmentation and reassembly of IP packets
-Indicates the type of TCP/IP transport protocol carried by this IP packet
-Contains the checksum of the IP header fields
-Contains the IP address of the sending host
-Contains the IP address of the receiving host
-Contains the header indicated by the Type field and the data contents
Fragment field Manages the fragmentation and reassembly of IP packets
TTL field Counts the number of times a packet passes through a router
Type field Indicates the type of TCP/IP transport protocol carried by this IP packet
IP checksum field Contains the checksum of the IP header fields
Source IP address field Contains the IP address of the sending host
,Destination IP address field Contains the IP address of the receiving host
Data field Contains the header indicated by the Type field and the data contents
Select the technical features of DES from the following list:
64
56
Originally, but no longer
Block size
Is this a U.S. government standard?
Key size
64 Block size
56 Key size
Originally, but no longer Is this a U.S. government standard?
The phrases below describe situations in which RSA is vulnerable to attack. Match the
attack with the method of use of RSA.
Small plaintext attack
!Small private key attack
Timing attack
-Accurately measuring how long it takes to decrypt an RSA-encrypted message provides
information about the private key value
-If the private key d value is relatively small, there is a mathematical shortcut for
recovering it
-If the public key value is 3 and the message length is less than one-third the length of the
modulus N, a shortcut attack can recover the message
,Small plaintext attack If the public key value is 3 and the message length is less than one-third
the length of the modulus N, a shortcut attack can recover the message
Small private key attack If the private key d value is relatively small, there is a mathematical
shortcut for recovering it
Timing attack Accurately measuring how long it takes to decrypt an RSA-encrypted message
provides information about the private key value
The phrases below describe terms and entities associated with encryption. Match the term
or entity with its description.
Web of trust
Public-key infrastructure (PKI)
Certificate authority
-A trusted third party that issues certificates
-Used to validate public keys and to use them safely
-No single person is universally trusted to sign certificates; individual users decide who
they trust to sign certificates
Web of trust = No single person is universally trusted to sign certificates; individual users
decide who they trust to sign certificates
Public-key infrastructure (PKI) = Used to validate public keys and to use them safely
Certificate authority = A trusted third party that issues certificates
Kevin is using Diffie–Hellman to share information with Tina. The following phrases
explain what he must do. Select the most appropriate phrases to describe the process.
private key
public key belonging to Tina
unique secret shared by Kevin and Tina
with the
, Kevin combines his own
to produce a
private key = Kevin combines his own
!public key belonging to Tina = with the
unique secret shared by Kevin and Tina = to produce a
A cryptonet:
c) is two or more people who share an encryption key and provides better key security
when the cryptonet has a large number of members.
a) is two or more people who share an encryption key.
b) provides better key security when the cryptonet has a large number of members.
d) None of these is correct.
a) is two or more people who share an encryption key.
Which of the following represents the best size for a cryptonet?
c) Anyone who might need access to the encrypted data
d) The fewest people who require access to the encrypted data
b) Everyone who requires access to the encrypted data
a) One person
d) The fewest people who require access to the encrypted data
When we share a key with two or more people, we refer to that group as being the:
d) cryptonet.
c) cryptanalysis.
b) privileged.
a) trusted.
d) cryptonet.
CORRECT ANSWERS.
The phrases below describe fields in an IP packet. Match the IP packet field with its
description.
Fragment field
TTL field
Type field
IP checksum field
Source IP address field
Destination IP address field
Data field
-Counts the number of times a packet passes through a router
-Manages the fragmentation and reassembly of IP packets
-Indicates the type of TCP/IP transport protocol carried by this IP packet
-Contains the checksum of the IP header fields
-Contains the IP address of the sending host
-Contains the IP address of the receiving host
-Contains the header indicated by the Type field and the data contents
Fragment field Manages the fragmentation and reassembly of IP packets
TTL field Counts the number of times a packet passes through a router
Type field Indicates the type of TCP/IP transport protocol carried by this IP packet
IP checksum field Contains the checksum of the IP header fields
Source IP address field Contains the IP address of the sending host
,Destination IP address field Contains the IP address of the receiving host
Data field Contains the header indicated by the Type field and the data contents
Select the technical features of DES from the following list:
64
56
Originally, but no longer
Block size
Is this a U.S. government standard?
Key size
64 Block size
56 Key size
Originally, but no longer Is this a U.S. government standard?
The phrases below describe situations in which RSA is vulnerable to attack. Match the
attack with the method of use of RSA.
Small plaintext attack
!Small private key attack
Timing attack
-Accurately measuring how long it takes to decrypt an RSA-encrypted message provides
information about the private key value
-If the private key d value is relatively small, there is a mathematical shortcut for
recovering it
-If the public key value is 3 and the message length is less than one-third the length of the
modulus N, a shortcut attack can recover the message
,Small plaintext attack If the public key value is 3 and the message length is less than one-third
the length of the modulus N, a shortcut attack can recover the message
Small private key attack If the private key d value is relatively small, there is a mathematical
shortcut for recovering it
Timing attack Accurately measuring how long it takes to decrypt an RSA-encrypted message
provides information about the private key value
The phrases below describe terms and entities associated with encryption. Match the term
or entity with its description.
Web of trust
Public-key infrastructure (PKI)
Certificate authority
-A trusted third party that issues certificates
-Used to validate public keys and to use them safely
-No single person is universally trusted to sign certificates; individual users decide who
they trust to sign certificates
Web of trust = No single person is universally trusted to sign certificates; individual users
decide who they trust to sign certificates
Public-key infrastructure (PKI) = Used to validate public keys and to use them safely
Certificate authority = A trusted third party that issues certificates
Kevin is using Diffie–Hellman to share information with Tina. The following phrases
explain what he must do. Select the most appropriate phrases to describe the process.
private key
public key belonging to Tina
unique secret shared by Kevin and Tina
with the
, Kevin combines his own
to produce a
private key = Kevin combines his own
!public key belonging to Tina = with the
unique secret shared by Kevin and Tina = to produce a
A cryptonet:
c) is two or more people who share an encryption key and provides better key security
when the cryptonet has a large number of members.
a) is two or more people who share an encryption key.
b) provides better key security when the cryptonet has a large number of members.
d) None of these is correct.
a) is two or more people who share an encryption key.
Which of the following represents the best size for a cryptonet?
c) Anyone who might need access to the encrypted data
d) The fewest people who require access to the encrypted data
b) Everyone who requires access to the encrypted data
a) One person
d) The fewest people who require access to the encrypted data
When we share a key with two or more people, we refer to that group as being the:
d) cryptonet.
c) cryptanalysis.
b) privileged.
a) trusted.
d) cryptonet.
