What are the general equations for encryption and decryption in the affine cipher?

What are the general equations for encryption and decryption in the affine cipher?

Answer:

E(x)= ax+b mod 26
D(y)= E^1 (y-b) mod 26

Describe a relationship between plaintext, encryption, decryption and cipher

Describe a relationship between plaintext, encryption, decryption and cipher

Answer:

text
Ciphertext=Encryption(Plaintext)
Plaintext=Decryption(Ciphertext)

Carlos wants to send a message to Alice so only she can understand it. He also wants to send a message to Bob so only Bob can understand it. How many private keys does Carlos need?

Carlos wants to send a message to Alice so only she can understand it. He also wants to send a message to Bob so only Bob can understand it. How many private keys does Carlos need?

A) 1
B) 2
C) 3
D) 0

Answer: D

The _________ attack can endanger the security of the Diffie-Hellman method if two parties are not authenticated to each other.

The _________ attack can endanger the security of the Diffie-Hellman method if two parties are not authenticated to each other.

A) man-in-the-middle
B) ciphertext attack
C) plaintext attack
D) none of the above

Answer: A

The ________ method provides a one-time session key for two parties.

The ________ method provides a one-time session key for two parties.

A) Diffie-Hellman
B) RSA
C) DES
D) AES

Answer: A

One commonly used public-key cryptography method is the ______ algorithm.

One commonly used public-key cryptography method is the ______ algorithm.

A) RSS
B) RAS
C) RSA
D) RAA

Answer: C

In an asymmetric-key cipher, the receiver uses the ______ key.

In an asymmetric-key cipher, the receiver uses the ______ key.

A) private
B) public
C) either (a) or (b)
D) neither (a) nor (b)

Answer: A

In an asymmetric-key cipher, the sender uses the__________ key.

In an asymmetric-key cipher, the sender uses the__________ key.

A) private
B) public
C) either (a) or (b)
D) neither (a) nor (b)

Answer: A

In a(n) ________ cipher, a pair of keys is used.

In a(n) ________ cipher, a pair of keys is used.

A) symmetric-key
B) asymmetric-key
C) either (a) or (b)
D) neither (a) nor (b)

Answer: B

In a(n) ________, the key is called the secret key.

In a(n) ________, the key is called the secret key.

A) symmetric-key
B) asymmetric-key
C) either (a) or (b)
D) neither (a) nor (b)

Answer: A

In a(n) ________ cipher, the same key is used by both the sender and receiver.

In a(n) ________ cipher, the same key is used by both the sender and receiver.

A) symmetric-key
B) asymmetric-key
C) either (a) or (b)
D) neither (a) nor (b)

Answer: A

The _______ is a number or a set of numbers on which the cipher operates.

The _______ is a number or a set of numbers on which the cipher operates. 

A) cipher
B) secret
C) key
D) none of the above

Answer: C

A combination of an encryption algorithm and a decryption algorithm is called a ________.

A combination of an encryption algorithm and a decryption algorithm is called a ________.

A) cipher
B) secret
C) key
D) none of the above

Answer: A

A(n) _______ algorithm transforms ciphertext to plaintext.

A(n) _______ algorithm transforms ciphertext to plaintext.

A) encryption
B) decryption
C) either (a) or (b)
D) neither (a) nor (b)

Answer: B

A(n) _______ algorithm transforms plaintext to ciphertext.

A(n) _______ algorithm transforms plaintext to ciphertext.

A) encryption
B) decryption
C) either (a) or (b)
D) neither (a) nor (b)

Answer: A

The ________ is the message after transformation.

The ________ is the message after transformation.

A) ciphertext
This is the correct answer.
B) plaintext
C) secret-text
D) none of the above

Answer: A

The ________is the original message before transformation.

The ________is the original message before transformation.

A) ciphertext
This is the correct answer.
B) plaintext
C) secret-text
D) none of the above

Answer: B

This is the name for the issuer of a PKI certificate.

This is the name for the issuer of a PKI certificate. 

a) man in the middle
b) certificate authority
c) Resource Access Control Facility
d) script kiddy

Answer: B

This is an encryption/decryption key known only to the party or parties that exchange secret messages.

This is an encryption/decryption key known only to the party or parties that exchange secret messages. 

a) e-signature
b) digital certificate
c) private key
d) security token

Answer: C

Cryptanalysis is used

Cryptanalysis is used

a) to find some insecurity in a cryptographic scheme
b) to increase the speed
c) to encrypt the data
d) none of the mentioned

Answer: A