3.3: Cryptography

Question 1

Encryption

Answer 1

The process of transforming plaintext into ciphertext.

Question 2

plaintext

Answer 2

Encryption is the act of hiding information in plain sight. read by anyone who has access to it.

Question 3

Ciphertext

Answer 3

A message, file, or stream of data that has been transformed by an encryption algorithm and rendered unreadable.

Question 4

Hash function

Answer 4

A cryptographic operation on a block of data that returns a fixed-length string of characters, used to verify the integrity of a message.

Question 5

Message Digest

Answer 5

The output of a cryptographic function

Question 6

Digital signature

Answer 6

The result of encrypting the hash of a message with the originator’s private encryption key, used to prove the authenticity and integrity of a message.

Question 7

Algorithm

Answer 7

A specific mathematical formula that is used to perform encryption, decryption, message digests, and digital signatures.

Question 8

Decryption

Answer 8

The process of transforming ciphertext into plaintext so that a recipient can read it.

Question 9

Cryptanalysis

Answer 9

An attack on a cryptosystem where the attacker is attempting to determine the encryption key that is used to encrypt messages.

Question 10

Encryption key

Answer 10

A block of characters, used in combination with an encryption algorithm, used to encrypt or decrypt a stream or blocks of data. An encryption key is also used to create and verify a digital signature.

Question 11

Key encrypting key

Answer 11

An encryption key that is used to encrypt another encryption key.

Question 12

Block cipher

Answer 12

An encryption algorithm that operates on blocks of data.

Question 13

Stream cipher

Answer 13

A type of encryption algorithm that operates on a continuous stream of data such as a video or audio feed.

Question 14

• Initialization vector (IV)

Answer 14

A random number that is needed by some encryption algorithms to begin the encryption process.

Question 15

• Symmetric encryption

Answer 15

Symmetric encryption refers to those methods where the same key is used to encrypt and decrypt the plaintext.

Question 16

• Asymmetric encryption , or public key cryptography A .

Answer 16

A method for encryption, decryption, and digital signatures that uses pairs of encryption keys, consisting of a public key and a private key .

Question 17

• Key exchange

Answer 17

A technique that is used by two parties to establish a symmetric encryption key when there is no secure channel available.

Question 18

• Nonrepudiation

Answer 18

The property of digital signatures and encryption that can make it difficult or impossible for a party to later deny having sent a digitally signed message, unless they admit to having lost control of their private encryption key.