WGU C839 INTRO TO CRYPTOGRAPHY OBJECTIVE ASSESSMENT ACTUAL EXAM 2025/2026 ACCURATE QUESTIONS WITH CORRECT DETAILED ANSWERS || 100% GUARANTEED PASS RECENT VERSION

WGU C839 INTRO TO CRYPTOGRAPHY OBJECTIVE ASSESSMENT ACTUAL EXAM 2025/2026 ACCURATE QUESTIONS WITH CORRECT DETAILED ANSWERS || 100% GUARANTEED PASS RECENT VERSION 1. Cryptography - ANSWER the science that studies encryption, which is the hiding of messages so that only the sender and receiver can read them. Cybersecurity, computer science, programming, and other IT career fields require a conceptual understanding of cryptography and familiarity with its basic vocabulary. 2. Caesar Cypher - ANSWER letter-by-letter method to make a cipher. For each letter, substitute another letter 4 letters ahead. For "a", write "d". 3. Employee B sends Employee A an encrypted message. What does employee A use to decrypt the message from employee B - ANSWER Employee As private key 4. Advanced encryption system (AES) - ANSWER is an example of a symmetric algorithm. RSA, SHA, and MD5 are not symmetric algorithms. 5. Employee A created a secret key and wants to send it to Employee B without any coworkers being able to decrypt the message. Which key needs to encrypt the message? - ANSWER Employee B's public key 6. Which type of cipher is ChaCha? - ANSWER stream 7. What is the key size for RC4 with WEP? - ANSWER 40 bits 8. What is the length (in bits) of an MD5 hash output? - ANSWER 128 bits 9. Which mode encrypts each group with the same key, leaving each group independent of the others? - ANSWER ECB Electronic Code Book (ECB) is a simple mode of operation with a block cipher that's mostly used with symmetric key encryption. It is a straightforward way of processing a series of sequentially listed message blocks. The input plaintext is broken into numerous blocks. 10. ECB - ANSWER Electronic Code Book 11. Which mode of block encryption results in the same outcome for matching blocks of a plaintext message? - ANSWER Electronic Code Book (ECB) 12. Which encryption mode always produces the same result for the same plaintext? - ANSWER Electronic Code Book (ECB) 13. Skipjack - ANSWER Promoted by the NSA. Skipjack uses an 80-bit key, supports the same four modes of operation as DES, and operates on 64-bit blocks of text. Skipjack provides cryptographic routines in support of Clipper and Capstone. Skipjack faced public opposition because it was developed so that the government could maintain information enabling legal authorities (with a search warrant or approval of the court) to reconstruct a Skipjack access key and decrypt private communications between affected parties. 14. How many transformation rounds does AES use with a 192-bit key? - ANSWER 12 15. How many transformation rounds does AES use with a 128-bit key? - ANSWER 10 16. What should be used when large amounts of data need to be encrypted and decrypted for secure storage based on groupings of 128, 192, or 256 bits? - ANSWER symmetric block 17. Why is symmetric stream used to encrypt video when speed is a major concern? - ANSWER It uses the same key to encrypt and decrypt large amounts of media. 18. Why should an asymmetric public key be used to encrypt a symmetric key that is being sent to one person? - ANSWER It encrypts a small amount of information, which is decrypted with the corresponding private key. 19. Which type of attacks are Diffie-Hellman methods vulnerable to? - ANSWER Man-in-the-middle 20. Which mechanism mitigates a copy-and-paste attack when using AES? - ANSWER Output feedback (OFB) loop 21. Which mechanism can be used to ensure perfect forward secrecy during key exchange when using symmetric encryption? - ANSWER ECDH 22. Which encryption component ensures that the compromise of a long-term key prevents the compromise of any previous session keys? - ANSWER Forward secrecy 23. What can XOR use as a pseudorandom number to create unique ciphertext? - ANSWER Initialization vector 24. How does cipher block chaining (CBC) create randomness in a second block after encrypting the first block with an initialization vector (IV)? - ANSWER Uses the results of the IV to encrypt the next block 25. How is information about Bitcoin transactions stored? - ANSWER Distributed peer-to-peer network 26. What is one of the primary characteristics of a blockchain in the context of Bitcoin? - ANSWER Adding blocks to a blockchain is computationally expensive. 27. What is the length (in bits) of the private key used to sign transactions and associated with an individual wallet in the context of Bitcoin? - ANSWER 256 28. Which certificate management process involves key recovery? - ANSWER Issued 29. Which task does a root CA perform before publishing its own certificate? - ANSWER Signing it with its private key 30. Which algorithm is used to generate the thumbprint of a certificate? - ANSWER SHA-1 31. Large volumes of plaintext need to be encrypted, and the encryption keys need to be securely distributed.Which approach should be used for encryption and distribution? - ANSWER Encrypt by using symmetric keys and distribute by using asymmetric keys 32. What is the role of a key in asymmetric encryption and decryption? - ANSWER A public key is used for encryption, and a private key is used for decryption. 33. A security analyst is validating the integrity and authenticity of a data transaction.Which PKI component is being used? - ANSWER Digital signature 34. Which PKI component generates digital certificates? - ANSWER Certificate authority (CA) 35. What is the maximum length (in bits) of encryption keys used by the WEP protocol? - ANSWER 40 36. What is a difference between WPA-Enterprise and WPA-Personal? - ANSWER Support for an authentication server 37. Which cipher is used with WEP? - ANSWER RC4 38. How does TKIP improve WPA over WEP? - ANSWER Hashes the initialization vector and secret key 39. An administrator has configured a virtual private network (VPN) connection utilizing IPsec tunnel mode with Encapsulating Security Payload (ESP) between the corporate office and a remote office.Where can the packets be inspected by intrusion detection systems (IDSs) and virus scanners? - ANSWER At the headquarters and the offsite location 40. Which default port must be open for the IPsec key exchange to be successful? - ANSWER UDP 500 41. Which protocol indicates the virtual private network (VPN) is using Authentication Header (AH)? - ANSWER 51 42. Which cipher uses a grid to map letters into numeric values? - ANSWER bifid 43. Which cipher uses a five-by-five matrix with nonrepeating characters? - ANSWER playfair 44. What does a frequency analysis attack to break encryption involve? - ANSWER Analyzing ciphertext to identify text variation and comparing the text to standard English characters 45. Which technique should a security analyst use to determine the key length in a Vigenère cipher? - ANSWER Kasiski examination 46. Which attack tries every combination of letters, numbers, and special characters? - ANSWER brute force 47. How does a dictionary attack break a cipher? - ANSWER Takes a list of the most common words and tries each entry A business wants to use keys issued by a trusted third party to demonstrate to potential customers that it is a legitimate organization.Which key is used to sign the certificate issued to the business? - ANSWER Private key of the root CA 48. A business wants to use keys issued by a trusted third party to demonstrate it is a legitimate organization to potential customers.Which key should the business send to potential customers to prove its identity? - ANSWER Public key of the company 49. What should an administrator use to import and export all items written using X.509 that are part of a chain of trust? - ANSWER Public Key Cryptography Standard (PKCS) #12 50. Which field displays the hash, or digest, of the certificate in an X.509 certificate? - ANSWER thumbprint 51. Employee B sends Employee A an encrypted message.What does Employee A use to decrypt the message from Employee B? - ANSWER Employee A's private key 52. What is an example of a symmetric algorithm? - ANSWER AES 53. Which two components involved in performing encryption are known to the party that will perform decryption before symmetric encryption is applied?Choose 2 answers. - ANSWER Cryptographic algorithm & Cryptographic key 54. Employee A created a secret key and wants to send it to Employee B without any coworkers being able to decrypt the message.Which key needs to encrypt the message? - ANSWER Employee B's public key 55. What type of encryption uses different keys to encrypt and decrypt the message? A Symmetric B Private key C Secure D Asymmetric - ANSWER D 56. The most widely used asymmetric encryption algorithm is what? A RSA B Vigenere C DES D Caesar Cipher - ANSWER A 57. Original, unencrypted information is referred to as ____. A text B plaintext C cleantext D ciphertext - ANSWER B 58. Which of the following is NOT an asymmetric system? A PGP B RSA C SSL D DES - ANSWER D 59. In order for User A to send User B an encrypted message that only User B can read, User A must encrypt message with which of the following keys? A User A's public key B User A's private key C User B's public key D User B's private key - ANSWER C 60. The greatest weakness with symmetric algorithms is _____. A They are less secure than asymmetric B The problem of key exchange C They are slower than asymmetric D The problem of generating keys - ANSWER B 61. Which of the following is generally true about block sizes? A Smaller block sizes increase security B Block sizes must be more than 256 bits to be secure C Block size is irrelevant to security D Larger block sizes increase security - ANSWER D 62. Asymmetric encryption method developed in 1984. It is used in PGP implementations and GNU Privacy Guard Software. Consists of 3 parts: key generator, encryption algorithm, and decryption algorithm. - ANSWER El Gamal 63. A combination of the ISAKMP and OAKLEY protocols. - ANSWER Internet Key Exchange (IKE) 64. The payload of the message is protected - ANSWER Transport mode 65. What did WPA replace RC4 with? - ANSWER TKIP (Temporal Key Integrity Protocol) 66. N denotes natural numbers. These are also sometimes called the counting numbers. They are 1, 2, 3, etc. 67. Z denotes the integers. These are whole numbers such as -1, 0, 1, 2, etc. Basically, this set is the natural numbers combined with zero and the negative numbers. 68. Q denotes rational numbers (or the ratios of integers). They are any number that can be expressed as a ratio of two integers. Examples are 3/2, 17/4, and 1/5. 69. CryptoBench - ANSWER used to see the output of a number of hashes. 70. More AES - ANSWER Advanced Encryption Standard, also Known as Rijndael block cipher, was ultimately chosen as a replacement for DES in 2001 after a 5 year process involving 15 competing algorithms 71. blowfish - ANSWER Blowfish is unpatented, and will remain so in all countries. The algorithm is hereby placed in the public domain, and can be freely used by anyone