Computer Science - ABCs of Cryptography

Asymmetric encryption: a. uses one key for encryption and a different key for decryption b. uses the same key for encryption and decryption c. doesn't use any keys at all

a

Compute the value of: 48 mod 6 = ? a. 0 b. 8 c. 2 d. 1

a

Cryptography is defined as: a. The practice of encoding information so only authorized people can read it b.Sensitive information sent over networks that needs to be secured c. Verified authority to view information, such as a password or key d. The act of stealing personal information online

a

Encrypted information is only viewable by authorized users who have the correct key to decrypt. This describes which aspect of the CIA triad? a. Confidentiality b. Integrity c. Availability d. Security

a

Hash functions got the name "hash" because it's easy to compute the function with a given input, but nearly impossible to reverse engineer the hash function to get the original input. a. True b. False

a

True or False: Computers have made it easier and faster to crack the Caesar cipher. a. True b. False

a

Which of the following shows the word "CAT" encrypted with the Caesar cipher with a key of 1? a. DBU b. CAT c. BZS d. Can not be encrypted.

a

Most attacks on hash functions involve: I. Finding collisions. II. Injecting a new hash function into the code. III. Pre-generating millions of hashes and comparing them to the plain text that generated it. IV. Really good random guessing. a. I-IV all b. I, II and III c. I and III d. II and IV

b

Symmetric encryption: a. uses one key for encryption and a different key for decryption b. uses the same key for encryption and decryption c. doesn't use any keys at all

b

True or False: A message in unencrypted form is called ciphertext. a. True b. False

b

True or False: Cracking a Vigenère cipher with brute force takes longer than a Caesar cipher, but it is still a reliable method for cracking the encryption. a. True b. False

b

What is the primary flaw with the Caesar Cipher and other substitution ciphers? a. It could not be applied to all messages b. With enough frequency, a message could be decrypted c. It could only be used in English d. There were too many options when encrypting a message

b

Compute the value of: 23 mod 4 = ? a. 1 b. 5 c. 3 d. 4

c

Public-key cryptography (a form of asymmetric cryptography) is an encryption method that's widely used because: I. It is computationally infeasible to compute the private key based on the public key. II. It's easier to share one public key than billions of private keys. III. It's much tougher to crack an asymmetric encryption than a symmetric one. IV. It's more secure because the private keys do not ever need to be transmitted or revealed to anyone. a. I only b. II only c. I - IV all

c

To decrypt an encrypted message, pass the encrypted message and the _____ to the decrypt function. a. cryptology b.decrypted message c. key d. ciphertext

c

Which of the following methods are effective in cracking the Caesar cipher? a. Brute force only b.Letter frequency analysis only c. Brute force and letter frequency analysis d. Neither-the Caesar cipher is too difficult to crack.

c

A primary requirement for a good cryptographic hash function is that the function should not produce too many collisions. A collision in a hash function is when: a. There are few inputs, but a lot of outputs. b. 2 inputs map to the same output. c. 2 outputs come from the same input. d. There are few outputs, but a lot of inputs.

d

Encryption plays a crucial role in maintaining which part(s) of the CIA triad? a. Confidentiality b. Integrity c. Availability d. Confidentiality and Integrity e. Integrity and Availability f. Confidentiality and Availability

d

Why do we use cryptography? a. To secure digital and non-digital data b. To allow important messages to be sent with lower chances of being interpreted c. To add security to the use of specific machinery d. All of the above

d