WGU C839 - Pre-Assessment:
Introduction to Cryptography(Q &
A)2023
Which encryption standard uses the same key to encrypt and decrypt messages? -
Answer Symmetric Key Encryption
Which algorithm is designated as a Type 2 product by the National Security Agency
(NSA)? - Answer SKIPJACK
What is the most commonly used format for certificates? - Answer X.509 v3 *Version
3*
What is referenced to determine if a certificate has been revoked? - Answer
Certificate Revocation List *(CRL)*
What needs to be installed on *end users' computers* to allow them to *trust*
applications that have been *digitally signed* by the developer? - Answer Sender's
public key *(DEVELOPER's)*
Which type of certificate *must be certified by an authority* to verify it with other
participants? - Answer Public Certificate
What is an attribute of the Rivest Cipher 4 (RC4) algorithm? - Answer It requires a
unique nonce. *(# used ONCE)*
Which mode generates the key stream with a nonce and incrementing value? -
Answer Counter (CTR)
*Generates the next keystream block* by encrypting successive *values* of a
"counter"
Which mode is a stream algorithm that concatenates an incrementing value with a
nonce? - Answer Counter (CTR)
Which key would an administrator use to encrypt data so *only the CEO can decrypt
it?* - Answer CEO's public key
Remember, when a specific person in an organization is the *ONLY* one you want
to *DECRYPT* something, you must have their *PUBLIC* key
What is the result of a hash function? - Answer Digest
What is used to efficiently encrypt *large files?* - Answer Symmetric encryption
, An administrator needs to encrypt the following word with the Atbash cipher:
*security*
Which ciphertext is correct? - Answer hvxfirgb
Remember this is a Mono-Alphabet Substitution Cipher that replaces each character
with its corresponding alphabet character *IE: A=Z, B=Y, C=X, etc...*
Which cryptographic algorithm has a 128-bit *HASH* size? - Answer Message
*Digest* Algorithm 5 (MD5)
Which characteristic makes a hashing function suitable for use in signature
schemes? - Answer Collision resistance
*Of the many properties that a good hash function should have, the one that is
mentioned most often is collision resistance.*
Which attribute of a hashing function makes a *birthday attack possible?* - Answer
*Partial-message collision*
The partial-message collision attacks *all rely on birthday attacks*
Which *hash* algorithm produces a 160-bit output value? - Answer SHA-1
What does cipher block chaining (CBC) use *with the key to encrypt subsequent
blocks* of plaintext? - Answer Previous generated ciphertext
Which mode produces the same ciphertext from two identical plaintext blocks? -
Answer Electronic codebook (ECB)
There are many situations in which large blocks of text are repeated. For example,
this chapter contains the words "ciphertext block" many times. If two of the
occurrences happen to line up on a block boundary, then a plaintext block value will
be repeated
Which encryption *mode is least secure?* - Answer Electronic codebook (ECB)
What is the mathematical formula used for symmetric decryption? - Answer *P = E
(K,C)*
P = Plain text
E = Encryption/Decryption
K = Key
C = Cipher Text
*Remember, if you DECRYPT something, you want to know the PLAIN TEXT*
Which algorithm relies on factoring the product of large prime numbers? - Answer
RSA
Introduction to Cryptography(Q &
A)2023
Which encryption standard uses the same key to encrypt and decrypt messages? -
Answer Symmetric Key Encryption
Which algorithm is designated as a Type 2 product by the National Security Agency
(NSA)? - Answer SKIPJACK
What is the most commonly used format for certificates? - Answer X.509 v3 *Version
3*
What is referenced to determine if a certificate has been revoked? - Answer
Certificate Revocation List *(CRL)*
What needs to be installed on *end users' computers* to allow them to *trust*
applications that have been *digitally signed* by the developer? - Answer Sender's
public key *(DEVELOPER's)*
Which type of certificate *must be certified by an authority* to verify it with other
participants? - Answer Public Certificate
What is an attribute of the Rivest Cipher 4 (RC4) algorithm? - Answer It requires a
unique nonce. *(# used ONCE)*
Which mode generates the key stream with a nonce and incrementing value? -
Answer Counter (CTR)
*Generates the next keystream block* by encrypting successive *values* of a
"counter"
Which mode is a stream algorithm that concatenates an incrementing value with a
nonce? - Answer Counter (CTR)
Which key would an administrator use to encrypt data so *only the CEO can decrypt
it?* - Answer CEO's public key
Remember, when a specific person in an organization is the *ONLY* one you want
to *DECRYPT* something, you must have their *PUBLIC* key
What is the result of a hash function? - Answer Digest
What is used to efficiently encrypt *large files?* - Answer Symmetric encryption
, An administrator needs to encrypt the following word with the Atbash cipher:
*security*
Which ciphertext is correct? - Answer hvxfirgb
Remember this is a Mono-Alphabet Substitution Cipher that replaces each character
with its corresponding alphabet character *IE: A=Z, B=Y, C=X, etc...*
Which cryptographic algorithm has a 128-bit *HASH* size? - Answer Message
*Digest* Algorithm 5 (MD5)
Which characteristic makes a hashing function suitable for use in signature
schemes? - Answer Collision resistance
*Of the many properties that a good hash function should have, the one that is
mentioned most often is collision resistance.*
Which attribute of a hashing function makes a *birthday attack possible?* - Answer
*Partial-message collision*
The partial-message collision attacks *all rely on birthday attacks*
Which *hash* algorithm produces a 160-bit output value? - Answer SHA-1
What does cipher block chaining (CBC) use *with the key to encrypt subsequent
blocks* of plaintext? - Answer Previous generated ciphertext
Which mode produces the same ciphertext from two identical plaintext blocks? -
Answer Electronic codebook (ECB)
There are many situations in which large blocks of text are repeated. For example,
this chapter contains the words "ciphertext block" many times. If two of the
occurrences happen to line up on a block boundary, then a plaintext block value will
be repeated
Which encryption *mode is least secure?* - Answer Electronic codebook (ECB)
What is the mathematical formula used for symmetric decryption? - Answer *P = E
(K,C)*
P = Plain text
E = Encryption/Decryption
K = Key
C = Cipher Text
*Remember, if you DECRYPT something, you want to know the PLAIN TEXT*
Which algorithm relies on factoring the product of large prime numbers? - Answer
RSA
