WGU D830 with questions
and well verified answers
actual exam!!! 2026
Cryptology - ANSWER -The study of cryptography and cryptanalysis together.
Cryptography - ANSWER -The practice of creating secure communication systems.
Cryptanalysis - ANSWER -The practice of breaking cryptographic systems.
Plaintext - ANSWER -Original readable data before encryption.
Ciphertext - ANSWER -Encrypted, unreadable data.
Key - ANSWER -A secret value used to encrypt or decrypt data.
Cipher - ANSWER -An algorithm used for encryption and decryption.
Encryption - ANSWER -The process of converting plaintext into ciphertext.
Decryption - ANSWER -The process of converting ciphertext back into plaintext.
Kerckhoffs's Principle - ANSWER -A cryptosystem should be secure even if the algorithm
is public; only the key must remain secret.
,Symmetric Cryptography - ANSWER -A type of encryption where the same key is used
for encryption and decryption.
Asymmetric Cryptography - ANSWER -A type of encryption that uses a public key and a
private key.
Public Key - ANSWER -A key that is shared publicly and used to encrypt data.
Private Key - ANSWER -A secret key used to decrypt data or create digital signatures.
One-Way Function - ANSWER -A function that is easy to compute but difficult to
reverse.
Trapdoor Function - ANSWER -A one-way function that can be reversed using secret
information.
Caesar Cipher - ANSWER -A substitution cipher that shifts letters by a fixed number.
Substitution Cipher - ANSWER -A cipher that replaces plaintext symbols with other
symbols.
Polyalphabetic Cipher - ANSWER -A cipher that uses multiple substitution alphabets.
Transposition Cipher - ANSWER -A cipher that rearranges plaintext characters without
replacing them.
One-Time Pad - ANSWER -A cipher that uses a random key equal in length to the
message and used only once.
Confusion - ANSWER -A property that hides the relationship between the key and
ciphertext.
, Diffusion - ANSWER -A property that spreads plaintext influence across ciphertext.
Block Cipher - ANSWER -A symmetric cipher that encrypts fixed-size blocks of data.
Padding - ANSWER -Extra bits added to fill a block when plaintext is too short.
AES (Advanced Encryption Standard) - ANSWER -A modern symmetric block cipher using
128-bit blocks.
DES (Data Encryption Standard) - ANSWER -A legacy symmetric block cipher using 56-bit
keys.
ECB Mode - ANSWER -A block cipher mode that encrypts each block independently
(insecure).
CBC Mode - ANSWER -A block cipher mode that chains blocks together using XOR and
an IV.
CFB Mode - ANSWER -A mode that turns a block cipher into a stream cipher.
OFB Mode - ANSWER -A mode that generates a keystream independent of plaintext and
ciphertext.
CTR Mode - ANSWER -A mode that uses a counter to generate a keystream.
Initialization Vector (IV) - ANSWER -A random value used to ensure unique ciphertexts.
Hash Function - ANSWER -A one-way function that produces a fixed-length output.
MAC (Message Authentication Code) - ANSWER -A keyed hash used for integrity and
authentication.
and well verified answers
actual exam!!! 2026
Cryptology - ANSWER -The study of cryptography and cryptanalysis together.
Cryptography - ANSWER -The practice of creating secure communication systems.
Cryptanalysis - ANSWER -The practice of breaking cryptographic systems.
Plaintext - ANSWER -Original readable data before encryption.
Ciphertext - ANSWER -Encrypted, unreadable data.
Key - ANSWER -A secret value used to encrypt or decrypt data.
Cipher - ANSWER -An algorithm used for encryption and decryption.
Encryption - ANSWER -The process of converting plaintext into ciphertext.
Decryption - ANSWER -The process of converting ciphertext back into plaintext.
Kerckhoffs's Principle - ANSWER -A cryptosystem should be secure even if the algorithm
is public; only the key must remain secret.
,Symmetric Cryptography - ANSWER -A type of encryption where the same key is used
for encryption and decryption.
Asymmetric Cryptography - ANSWER -A type of encryption that uses a public key and a
private key.
Public Key - ANSWER -A key that is shared publicly and used to encrypt data.
Private Key - ANSWER -A secret key used to decrypt data or create digital signatures.
One-Way Function - ANSWER -A function that is easy to compute but difficult to
reverse.
Trapdoor Function - ANSWER -A one-way function that can be reversed using secret
information.
Caesar Cipher - ANSWER -A substitution cipher that shifts letters by a fixed number.
Substitution Cipher - ANSWER -A cipher that replaces plaintext symbols with other
symbols.
Polyalphabetic Cipher - ANSWER -A cipher that uses multiple substitution alphabets.
Transposition Cipher - ANSWER -A cipher that rearranges plaintext characters without
replacing them.
One-Time Pad - ANSWER -A cipher that uses a random key equal in length to the
message and used only once.
Confusion - ANSWER -A property that hides the relationship between the key and
ciphertext.
, Diffusion - ANSWER -A property that spreads plaintext influence across ciphertext.
Block Cipher - ANSWER -A symmetric cipher that encrypts fixed-size blocks of data.
Padding - ANSWER -Extra bits added to fill a block when plaintext is too short.
AES (Advanced Encryption Standard) - ANSWER -A modern symmetric block cipher using
128-bit blocks.
DES (Data Encryption Standard) - ANSWER -A legacy symmetric block cipher using 56-bit
keys.
ECB Mode - ANSWER -A block cipher mode that encrypts each block independently
(insecure).
CBC Mode - ANSWER -A block cipher mode that chains blocks together using XOR and
an IV.
CFB Mode - ANSWER -A mode that turns a block cipher into a stream cipher.
OFB Mode - ANSWER -A mode that generates a keystream independent of plaintext and
ciphertext.
CTR Mode - ANSWER -A mode that uses a counter to generate a keystream.
Initialization Vector (IV) - ANSWER -A random value used to ensure unique ciphertexts.
Hash Function - ANSWER -A one-way function that produces a fixed-length output.
MAC (Message Authentication Code) - ANSWER -A keyed hash used for integrity and
authentication.
