WGU C839 - Pre-Assessment: Introduction to Cryptography | 60 Questions and Answers(A+ Solution guide)

Which encryption standard uses the same key to encrypt and decrypt messages? - Symmetric Key Encryption Which algorithm is designated as a Type 2 product by the National Security Agency (NSA)? - SKIPJACK What is the most commonly used format for certificates? - X.509 v3 *Version 3* What is referenced to determine if a certificate has been revoked? - 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? - Sender's public key *(DEVELOPER's)* Which type of certificate *must be certified by an authority* to verify it with other participants? - Public Certificate What is an attribute of the Rivest Cipher 4 (RC4) algorithm? - It requires a unique nonce. *(# used ONCE)* Which mode generates the key stream with a nonce and incrementing value? - 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? - Counter (CTR)Which key would an administrator use to encrypt data so *only the CEO can decrypt it?* - 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? - Digest What is used to efficiently encrypt *large files?* - Symmetric encryption An administrator needs to encrypt the following word with the Atbash cipher: *security* Which ciphertext is correct? - 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? - Message *Digest* Algorithm 5 (MD5) Which characteristic makes a hashing function suitable for use in signature schemes? - 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?* - *Partial-message collision*The partial-message collision attacks *all rely on birthday attacks* Which *hash* algorithm produces a 160-bit output value? - SHA-1 What does cipher block chaining (CBC) use *with the key to encrypt subsequent blocks* of plaintext? - Previous generated ciphertext