WGU Course C839 - Intro to Cryptography

WGU Course C839 - Intro to Cryptography Questions Correctly Answered!! What type of encryption uses different keys to encrypt and decrypt the message? A Symmetric B Private key C Secure D Asymmetric - Answer D The most widely used asymmetric encryption algorithm is what? A RSA B Vigenere C DES D Caesar Cipher - Answer A Original, unencrypted information is referred to as . A text B plaintext C cleantext D ciphertext - Answer B Which of the following is NOT an asymmetric system? A PGP B RSA C SSL D DES - Answer D 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 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 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 A is a function that takes a variable-size input m and returns a fixed-size string. A Symmetric cipher B Hash C Asymmetric cipher D Feistel - Answer B Which of the following is a cryptographic protocol that allows two parties to establish a shared key over an insecure channel? A Elliptic Curve B RSA C MD5 D Diffie-Hellman - Answer D A is a digital representation of information that identifies you as a relevant entity by a trusted third party? A Digital Signature B Hash C Ownership stamp D Digest - Answer A What is the standard used by most digital certificates? A X.509 B CRL C RFC 2298 D OCSP - Answer A DES uses keys of what size? A 56 bits B 192 bits C 128 bits D 64 bits - Answer A Which of the following is NOT a key size used by AES? A 512 bits B 128 bits C 192 bits D 256 bits - Answer A Which of the following was a multi alphabet cipher widely used from the 16th century (1553) to the early 20th century (1900s)? A Vigenere B Caesar C Atbash D Scytale - Answer A Which of the following is a substitution cipher used by ancient Hebrew scholars? A Caesar B Vigenere C Scytale D Atbash - Answer D Shifting each letter in the alphabet a fixed number of spaces to the right or left is an example of what? A Bit shifting B Confusion C Multi substitution D Single substitution - Answer D Which of the following most accurately defines encryption? A changing a message so it can only be easily read by the intended recipient B Making binary changes to a message to conceal it C changing a message using complex mathematics D Applying keys to plain text - Answer A If you use substitution alone, what weakness is present in the resulting cipher text? A It is the same length as the original text B It is easily broken with modern computers. C It is too simple. D Because it maintains letter and word frequency. - Answer D uses at least two different shifts, changing the shift with different letters in the plain text. A Atbash B multi-alphabet encryption C Scytale