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C845 Information Systems Security: Chapter 5
Questions with Correct Answers | Updated
(100% Correct Answers)
Cryptography Answer: The use of mathematical algorithms to
transform information into an encrypted form that is not readable
by unauthorized individuals.
Encryption Answer: The process of converting information from
plaintext form into ciphertext.
Decryption Answer: The process of converting ciphertext messages
back into their plaintext form.
Algorithm Answer: A set of rules or processes that serve as
mathematical recipes.
Symmetric Encryption Answer: Encryption and decryption methods
that use the same secret key.
Asymmetric Encryption Answer: Encryption and decryption methods
that use different keys from the same pair.
Required # of Symmetric Keys Algorithm Answer: n(n-1)/2, where n
is the number of keys.
© 2025 All rights reserved
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Public Key Answer: A key freely distributed to communication
partners.
Private Key Answer: A key kept secret and used for decryption.
Data at Rest Answer: Information stored on a hard drive or other
storage.
Data in Transit Answer: Information transmitted over a network
connection.
Data in Use Answer: Information actively processed in memory.
Obfuscation Answer: The act of hiding sensitive data.
Cipher Answer: A system that uses mathematical algorithms to
encrypt and decrypt messages.
Stream Cipher Answer: A cipher that operates on one character or
bit of a message at a time.
Block Cipher Answer: A cipher that operates on large segments of
the message at the same time.
Substitution Cipher Answer: A cipher that changes the characters in
a message.
Transposition Cipher Answer: A cipher that rearranges the
characters in a message.
© 2025 All rights reserved
C845 Information Systems Security: Chapter 5
Questions with Correct Answers | Updated
(100% Correct Answers)
Cryptography Answer: The use of mathematical algorithms to
transform information into an encrypted form that is not readable
by unauthorized individuals.
Encryption Answer: The process of converting information from
plaintext form into ciphertext.
Decryption Answer: The process of converting ciphertext messages
back into their plaintext form.
Algorithm Answer: A set of rules or processes that serve as
mathematical recipes.
Symmetric Encryption Answer: Encryption and decryption methods
that use the same secret key.
Asymmetric Encryption Answer: Encryption and decryption methods
that use different keys from the same pair.
Required # of Symmetric Keys Algorithm Answer: n(n-1)/2, where n
is the number of keys.
© 2025 All rights reserved
, 2
Public Key Answer: A key freely distributed to communication
partners.
Private Key Answer: A key kept secret and used for decryption.
Data at Rest Answer: Information stored on a hard drive or other
storage.
Data in Transit Answer: Information transmitted over a network
connection.
Data in Use Answer: Information actively processed in memory.
Obfuscation Answer: The act of hiding sensitive data.
Cipher Answer: A system that uses mathematical algorithms to
encrypt and decrypt messages.
Stream Cipher Answer: A cipher that operates on one character or
bit of a message at a time.
Block Cipher Answer: A cipher that operates on large segments of
the message at the same time.
Substitution Cipher Answer: A cipher that changes the characters in
a message.
Transposition Cipher Answer: A cipher that rearranges the
characters in a message.
© 2025 All rights reserved
