WGU D334 INTRODUCTION TO CRYPTOGRAPHY ALL-IN-ONE STUDY
GUIDE 2026/2027 | SHAWN C839V5 / D334 | COMPLETE EXAM PREP |
HIGH-YIELD PRACTICE QUESTIONS | VERIFIED ANSWERS| LATEST
UPDATED VERSION
1. If a file is transmitted over a network and a CRC is used, what would happen if
the CRC value does not match the received data?
The transmission will be retried without any checks.
The data will be accepted as correct.
An error will be detected in the data.
The data will be automatically corrected.
2. Describe how effective key management contributes to the overall security
of cryptographic systems.
Effective key management focuses solely on generating new keys.
Effective key management protects cryptographic keys, which are
essential for safeguarding sensitive information from unauthorized
access.
Effective key management eliminates the need for encryption
altogether.
Effective key management ensures that all data is encrypted using the
same key.
3. If a message of 50 bytes needs to be encrypted using a block cipher that
requires 64-byte blocks, how would padding be applied in this scenario?
Padding would add 50 bytes to the message to make it a full 64-byte
block.
Padding would not be necessary since the message is already 50
bytes.
, Padding would remove 14 bytes from the message to fit it into a 64-
byte block.
Padding would add 14 bytes to the message to make it a full 64-
byte block.
4. What is the structure used in the Playfair cipher for encryption?
4 × 4 matrix of symbols
5 × 5 matrix of letters
6 × 6 matrix of characters
3 × 3 matrix of numbers
5. DES with a 56-bit key is supported by SSL. DES-56 is insecure because
the cipher can be broken in under 24-hours.
the algorithm is in the public domain.
6. What is the primary purpose of a homophonic substitution code in
cryptography?
To obscure letter and symbol probability.
To enhance key management.
To simplify the encryption process.
To ensure data integrity.
7. What is the primary function of the Diffie-Hellman algorithm?
To encrypt data using symmetric keys
To generate random numbers for encryption
To hash passwords for storage
, To securely exchange secret keys
8. What is true about ASCII (best answer)?
A. ASCII uses 1 byte (8 bits) to represent a character.
B. ASCII can represent a total of 256 characters.
C. All of the above.
9. If a file is 1.5 MB in size, how would symmetric block encryption handle the
encryption of this file if the block size is 256 bits?
Only the first 256 bits of the file would be encrypted.
The entire file would be encrypted as a single block.
The file would be divided into multiple 256-bit blocks for
encryption.
The file would be compressed before encryption.
10. If Alice wants to send a secure message to Bob using public key encryption,
what steps must she take?
Alice must encrypt the message using her own private key.
Alice must send her private key to Bob for decryption.
Alice must send the message in plain text for Bob to encrypt.
Alice must use Bob's public key to encrypt the message before
sending it.
11. What is a mode of operation for a block cipher?
A way to improve the security of a block cipher
A choice of a particular block cipher to do encryption
, A method of applying a block cipher to encrypt data which is
longer than one block.
A method to ensure message integrity during encryption with a block
cipher
12. What is the difference between big endian and little endian?
A big-endian machine stores the most significant byte first. A little-
endian machine stores the least significant byte first.
Big-endian boots faster than little endian
Big endian and little endian yield the same hex structure
13. In a scenario where a video stream is being transmitted live over the
internet, which type of cipher would be more appropriate to use and why?
Block cipher, because it provides stronger security by encrypting
larger data chunks.
Hashing, because it ensures data integrity without encryption.
Stream cipher, because it encrypts data one bit or byte at a time,
making it suitable for real-time applications.
Asymmetric cipher, because it allows for secure key exchange.
14. Describe how the Diffie-Hellman algorithm contributes to secure
communications in symmetric cryptography.
The Diffie-Hellman algorithm encrypts messages using a public key.
The Diffie-Hellman algorithm generates random keys for symmetric
encryption.
The Diffie-Hellman algorithm allows two parties to generate a
shared secret key over an insecure channel, enabling secure
communication.
GUIDE 2026/2027 | SHAWN C839V5 / D334 | COMPLETE EXAM PREP |
HIGH-YIELD PRACTICE QUESTIONS | VERIFIED ANSWERS| LATEST
UPDATED VERSION
1. If a file is transmitted over a network and a CRC is used, what would happen if
the CRC value does not match the received data?
The transmission will be retried without any checks.
The data will be accepted as correct.
An error will be detected in the data.
The data will be automatically corrected.
2. Describe how effective key management contributes to the overall security
of cryptographic systems.
Effective key management focuses solely on generating new keys.
Effective key management protects cryptographic keys, which are
essential for safeguarding sensitive information from unauthorized
access.
Effective key management eliminates the need for encryption
altogether.
Effective key management ensures that all data is encrypted using the
same key.
3. If a message of 50 bytes needs to be encrypted using a block cipher that
requires 64-byte blocks, how would padding be applied in this scenario?
Padding would add 50 bytes to the message to make it a full 64-byte
block.
Padding would not be necessary since the message is already 50
bytes.
, Padding would remove 14 bytes from the message to fit it into a 64-
byte block.
Padding would add 14 bytes to the message to make it a full 64-
byte block.
4. What is the structure used in the Playfair cipher for encryption?
4 × 4 matrix of symbols
5 × 5 matrix of letters
6 × 6 matrix of characters
3 × 3 matrix of numbers
5. DES with a 56-bit key is supported by SSL. DES-56 is insecure because
the cipher can be broken in under 24-hours.
the algorithm is in the public domain.
6. What is the primary purpose of a homophonic substitution code in
cryptography?
To obscure letter and symbol probability.
To enhance key management.
To simplify the encryption process.
To ensure data integrity.
7. What is the primary function of the Diffie-Hellman algorithm?
To encrypt data using symmetric keys
To generate random numbers for encryption
To hash passwords for storage
, To securely exchange secret keys
8. What is true about ASCII (best answer)?
A. ASCII uses 1 byte (8 bits) to represent a character.
B. ASCII can represent a total of 256 characters.
C. All of the above.
9. If a file is 1.5 MB in size, how would symmetric block encryption handle the
encryption of this file if the block size is 256 bits?
Only the first 256 bits of the file would be encrypted.
The entire file would be encrypted as a single block.
The file would be divided into multiple 256-bit blocks for
encryption.
The file would be compressed before encryption.
10. If Alice wants to send a secure message to Bob using public key encryption,
what steps must she take?
Alice must encrypt the message using her own private key.
Alice must send her private key to Bob for decryption.
Alice must send the message in plain text for Bob to encrypt.
Alice must use Bob's public key to encrypt the message before
sending it.
11. What is a mode of operation for a block cipher?
A way to improve the security of a block cipher
A choice of a particular block cipher to do encryption
, A method of applying a block cipher to encrypt data which is
longer than one block.
A method to ensure message integrity during encryption with a block
cipher
12. What is the difference between big endian and little endian?
A big-endian machine stores the most significant byte first. A little-
endian machine stores the least significant byte first.
Big-endian boots faster than little endian
Big endian and little endian yield the same hex structure
13. In a scenario where a video stream is being transmitted live over the
internet, which type of cipher would be more appropriate to use and why?
Block cipher, because it provides stronger security by encrypting
larger data chunks.
Hashing, because it ensures data integrity without encryption.
Stream cipher, because it encrypts data one bit or byte at a time,
making it suitable for real-time applications.
Asymmetric cipher, because it allows for secure key exchange.
14. Describe how the Diffie-Hellman algorithm contributes to secure
communications in symmetric cryptography.
The Diffie-Hellman algorithm encrypts messages using a public key.
The Diffie-Hellman algorithm generates random keys for symmetric
encryption.
The Diffie-Hellman algorithm allows two parties to generate a
shared secret key over an insecure channel, enabling secure
communication.
