Deck 16: Security and Encryption

Question 1

In the RSA system, every person has a set of two keys, a(n) ____________ one and a private (secret) one.

Answer 1

public

Question 2

When sending a message using the RSA encryption algorithm, what key do we use to encrypt our message?

A) None; we do not encrypt our message
B) None; we do not use a key to encrypt our message
C) Our private key
D) Our public key

Answer 2

Our private key

Question 3

Passwords are typically encrypted using a one-way encryption algorithm.

Answer 3

True

Question 4

AES stands for Advanced Encryption ____________.

Question 5

The ____________ class provides access to implementations of encryption and decryption algorithms.

Question 6

We can call the getProviders method of the ____________ class to get a list of encryption algorithms available on a device.

Question 7

When calling the init method of the Cipher class, if we want to decrypt, we can pass the ____________ constant of the Cipher class as the first argument of init.

Question 8

PrivateKey and PublicKey are classes.

Question 9

Once we have built a Cipher object reference specifying that it uses RSA, the call to the doFinal method is identical to the call to doFinal if it uses another algorithm, such as AES.

Question 10

The getInstance method of the KeyPairGenerator class is static.

Question 11

The KeyPairGenerator class is abstract.

Question 12

The parameter of the initialize method of the KeyPairGenerator class is an int that represents the key size in bytes.

Question 13

To build a Cipher object reference, we call the getInstance method of the Cipher class and pass the String RSA.

Question 14

When receiving a message from somebody else and decrypting it using the RSA encryption algorithm, what key do we use to decrypt the message?

A) None; the message was not encrypted.
B) None; we do not use a key to decrypt our message.
C) We use the message sender's private key.
D) We use the message's sender public key.

Question 15

Which one of these numbers is not a composite number?

A) 55
B) 253
C) 88
D) 33

Question 16

To get a Cipher reference, we use a method of the Cipher class that takes one parameter. What can you say about that parameter?

A) It is an int that represents a resource.
B) It is a String that represents the name of an encryption algorithm.
C) It is a boolean (true or false; encryption or no encryption).
D) It is a char that represents the first letter of an encryption algorithm.

Question 17

What is the return type of the getPrivate method of the KeyPair class?

A) KeyPair
B) Key
C) PrivateKey
D) Private

Question 18

What is the return type of the getPublic method of the KeyPair class?

A) KeyPair
B) Key
C) PublicKey
D) Private

Question 19

77 is a composite number.

Question 20

The __________________ package contains classes and interfaces that encapsulate cryptology concepts.

Question 21

When calling the init method of the Cipher class, if we want to encrypt, we can pass the __________________ constant of the Cipher class as the first argument of init.

Question 22

The getEncoded method of the Key interface returns an array of __________________.

Question 23

The KeyPair and KeyPairGenerator classes are in the __________________ package.