Lesson 4: Explaining Basic
Cryptography Concepts Study Guide
Exam And Actual Answers.
Which part of a simple cryptographic system must be kept secret?
A) The cipher
B) The ciphertext
C) The key
D) All of the above - Answer C
True or false? Cryptography is about keeping things secret so they cannot be used as the basis of a non-
repudiation system. - Answer False (Usages are not exclusive)
What is confusion? (Choose all that apply)
A) The predictable features of the plaintext should not be evident in the ciphertext
B) The key should not be derivable from the ciphertext
C) Use complex substitution operations
D) Use transposition operations - Answer B, C
What is diffusion? (Choose all that apply)
A) The predictable features of the plaintext should not be evident in the ciphertext
B) The key should not be derivable from the ciphertext
C) Use complex substitution operations
D) Use transposition operations - Answer A, D
What is a means for the system to generate entropy so that it can generate random (or pseudo-random)
values for use as input into the cryptographic algorithms?
A) Key
B) Seed
, C) Trapdoor function
D) Salt - Answer B
What term is used to describe the state of data stored on the flash drive memory of a smartphone?
A) Data in transit
B) Data in use
C) Data at rest
D) Data in storage - Answer C
What is the main crypto-module for Windows?
A) CryptoNG
B) API
C) WindowsCrypto
D) CryptoSuite - Answer A
Which offers better security—MD5 or SHA? - Answer SHA
What is the principal use of symmetric encryption?
A) Authentication
B) Authorization
C) Non-repudiation
D) Confidentiality - Answer D
Which symmetric cipher is being selected for use in many new products?
A) DES
B) 3DES
C) AES
D) Blowfish - Answer C
Cryptography Concepts Study Guide
Exam And Actual Answers.
Which part of a simple cryptographic system must be kept secret?
A) The cipher
B) The ciphertext
C) The key
D) All of the above - Answer C
True or false? Cryptography is about keeping things secret so they cannot be used as the basis of a non-
repudiation system. - Answer False (Usages are not exclusive)
What is confusion? (Choose all that apply)
A) The predictable features of the plaintext should not be evident in the ciphertext
B) The key should not be derivable from the ciphertext
C) Use complex substitution operations
D) Use transposition operations - Answer B, C
What is diffusion? (Choose all that apply)
A) The predictable features of the plaintext should not be evident in the ciphertext
B) The key should not be derivable from the ciphertext
C) Use complex substitution operations
D) Use transposition operations - Answer A, D
What is a means for the system to generate entropy so that it can generate random (or pseudo-random)
values for use as input into the cryptographic algorithms?
A) Key
B) Seed
, C) Trapdoor function
D) Salt - Answer B
What term is used to describe the state of data stored on the flash drive memory of a smartphone?
A) Data in transit
B) Data in use
C) Data at rest
D) Data in storage - Answer C
What is the main crypto-module for Windows?
A) CryptoNG
B) API
C) WindowsCrypto
D) CryptoSuite - Answer A
Which offers better security—MD5 or SHA? - Answer SHA
What is the principal use of symmetric encryption?
A) Authentication
B) Authorization
C) Non-repudiation
D) Confidentiality - Answer D
Which symmetric cipher is being selected for use in many new products?
A) DES
B) 3DES
C) AES
D) Blowfish - Answer C
