WGU C839 - Intro to Cryptography with 100% Verified Questions And Answers

A hash is a function that takes a variable-size input m and returns a fixed-size string.

Which of the following is a cryptographic protocol that allows two parties to establish a shared key over an insecure channel?

A digital representation of information that identifies you as a relevant entity by a trusted third party is called what?

What is the standard used by most digital certificates?

DES uses keys of what size?

Which of the following is NOT a key size used by AES?

Which of the following was a multi alphabet cipher widely used from the 16th century (1553) to the early 20th century (1900s)?

Which of the following is a substitution cipher used by ancient Hebrew scholars?

Shifting each letter in the alphabet a fixed number of spaces to the right or left is an example of what?

If you use substitution alone, what weakness is present in the resulting cipher text?

Multi-alphabet encryption uses at least two different shifts, changing the shift with different letters in the plain text.

Blowfish was designed to provide built-in cryptography for the clipper chip.

Which of the following uses an 80 bit key on 64 bit blocks?

With electronic codebook (ECB), the message is divided into blocks and each block is encrypted separately. This is the most basic mode for symmetric encryption.

Which of the following is an example of an unbalanced Feistel?

This process is done by having each block of plaintext XORed with the previous ciphertext block before being encrypted.

The process wherein the ciphertext block is encrypted then the ciphertext produced is XORd back with the plaintext to produce the current ciphertext block is called what?

This is a method for turning a block cipher into a stream cipher by generating a keystream block, which is then XORed with the plaintext blocks to get the ciphertext.

Which of the following modes can be used to turn a block cipher into a stream cipher?

A fixed-size pseudorandom number that is fed into a symmetric cipher to increase randomness is called what?

A number that is used only one time then discarded is called what?

Which of the following is a stream cipher that uses a variable-length key from 1 to 256 bytes?

This algorithm was published by the German engineering firm Siemens in 1993. It is a software-based stream cipher using a Lagged Fibonacci generator along with a concept borrowed from the shrinking generator ciphers.

Which of the following is NOT required for a hash?