WGU C839 Introduction to Cryptography Exam Questions and Answers

WGU C839 Introduction to Cryptography Exam Questions and Answers Which encryption standard uses the same key to encrypt and decrypt messages? - Answer-Symmetric 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 -Answer-X.509 v3 What is referenced to determine if a certificate has been revoked?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 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. Which mode generates the key stream with a nonce and incrementing value? -Answer- Counter (CTR) 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 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 What is the correct ciphertext? -Answer-hvxfirgb 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 Which attribute of a hashing function makes a birthday attack possible? -Answer-Partial- message collision 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) Which encryption mode is least secure? -Answer-Electronic codebook (ECB) What is the mathematical formula used for symmetric decryption? -Answer-P = E (K,C) Which algorithm relies on factoring the product of large prime numbers? -Answer- Rivest-Shamir-Adleman Which encryption technology is a serial combination of hashing, data compression, symmetric-key cryptography, and public key infrastructure (PKI) and can be used for encrypting texts, emails, files, and directories or for full disk encryption? -Answer-Pretty Good Privacy (PGP) Which concept stipulates that algorithms should be openly shared and scrutinized, but keys must be absolutely secured? -Answer-Kerckhoffs's principle Which encryption process minimizes known plaintext attacks against Advanced Encryption Standard (AES)? -Answer-Randomizing the initialization vector What prevents a rainbow table attack during the encryption process? -Answer-Salting Which factor increases the required number of attempts in a brute-force attack? - Answer-Larger key size What is a vulnerability of the Data Encryption Standard (DES)? -Answer-Key length is too short. Which block size does the Advanced Encryption Standard (AES) use? -Answer-128 Which block algorithm includes a provision for the decryption key kept in a key escrow? -Answer-Skipjack What is the result of A|B and B|C? -Answer-A|C How is X mod N if N = PQ represented in number theory? -Answer-( X mod P, X mod Q) What is the outcome when using the binary AND function on 11011 and 10100? - Answer-10000