WGU C839 – Introduction to
Cryptography Actual Exam-NEW
UPDATE, 2023-2024 with 100% Correct
Answers and Short detailed
explanations.
A group of
... [Show More] PRNGs
Uses a seed file. ---------- Correct Answer -------- Fortuna
A sequence of numbers by adding the previous two numbers to create the next. Can be
added, multiplied or XOR. ---------- Correct Answer -------- Lagged Fibonacci Generator
(LFG)
Secures websites and prove identity. Uses CA to trust cert. ---------- Correct Answer -----
--- Secure Socket Layer (SSL)
Based on the practical difficulty of factoring the product of two large prime numbers.
Key Size: 1024 - 4,096 bits. ---------- Correct Answer -------- Rivest Shamir Aldeman
(RSA)
Free tool to use historic algorithms (Caesar, Atbash, ROT13, etc). Used to perform RSA
encryption. Can create public and private keys. ---------- Correct Answer -------- CrypTool
The most widely used digital certificate standard. First issued on July 3rd, 1988. Certs
are bound to Public Key. Relied on S/MIME. ---------- Correct Answer -------- X.509
Contains digital certs and public keys. Users identified via CA. Contains CRL and new
method Online Certificate Status Protocol (OSCP). ---------- Correct Answer -------- PKI
(Public Key Infrastructure)
• Password Authentication Protocol (PAP) Username/Password over HTTP sent in clear
text. Main weakness to PAP.
• Shiva Password Authentication Protocol (SPAP) is like PAP but sent over encrypted
channels.
• Challenge Handshake Authentication Protocol (CHAP) it shares a hash with the client
system. Challenge is sent with acknowledgment, otherwise connection is terminated. ---
------- Correct Answer -------- The Different Authentication Protocols
Encrypted "ticket" to user's machine. Ticket Granting Server (TGS) and Authentication
Server(AS) runs on Key Distribution Center (KDC). ---------- Correct Answer --------
Kerberos
Uses RC4 stream cipher. 40 bit key with 24 bit IV to combine a 64 bit encryption. 128
Bit WEP uses 104 bit with 24 bit IV. Same traffic key must never be used twice. 50
percent change every 5000 packets to use the same key.
Transmits the IV in plaintext ---------- Correct Answer -------- Wired Equivalent Privacy
(WEP)
Symmetric Block Cipher
Block Size: 64 bits
Key Size: Key bundle
Rounds: 48 ---------- Correct Answer -------- Triple DES (3DES)
Symmetric Block Mode Ciphers
Key Size: Variable up to 2048 ---------- Correct Answer -------- RC5 and RC6
Symmetric Block Cipher
Block Size: 128 bits
Key Size: Up to 256 bits
Feistel Cipher ---------- Correct Answer -------- Twofish
Symmetric Block Cipher
Block Size: 64 bits
Key Size: 32 - 448 bits
Rounds: 16
Feistel Cipher ---------- Correct Answer -------- Blowfish
Symmetric Block Cipher
Block Size: 64 bits
Key Size: 80 bits
Rounds: 32
Built by NSA for clipper chip ---------- Correct Answer -------- Skipjack
Asymmetric
Key Size: Variable up to 160 bits
• Uses an elliptic curve to generate key pairs
• The size of the curve determines the difficulty of finding the algorithm [Show Less]