CIS 481 - Chapter 8

Registration authority

a third party that operates under the trusted collaboration of the certificate authority and handles day-to-day certification functions

Hash functions

algorithms that generate a message summary to confirm message identity and integrity

Symmetric encryption

cryptographic method in which the same algorithm and secret key are used to encipher/decipher the message

Asymmetric encryption

cryptographic method that incorporates mathematical operations involving both a public key and a private key to encipher and decipher the message

Transposition cipher

cryptographic operation that involves rearranging the values within a block based on an established pattern

Digital signatures

encrypted message components that can be mathematically proven as authentic

Substitution cipher

encryption method in which one value is substituted for another

Bit stream cipher

encryption method that involves converting plaintext to ciphertext one bit at a time

Keyspace

entire range of values that can be used to construct an individual key

Cryptology

field of science that encompasses cryptography and cryptanalysis

Exclusive OR operation

function within Boolean algebra used as an encryption function in which 2 bits are compared

Hash algorithm

functions that create a hash value by converting variable-length messages into a single fixed-length value

Diffie-Hellman key exchange

hybrid cryptosystem that facilitates exchanging private keys using public-key encryption

Certificate authority

in PKI, a third party that manages users' digital certificates

Public key infrastructure

integrated system of software, encryption methodologies, protocols, legal agreements, and third party services that enables users to communicate securely through the use of digital certificates

Secret key

key that can be used in symmetric encryption both to decipher and encipher the message

Message authentication code

key-dependent, one-way hash function that allows only specific recipients to access the message digest

Session keys

limited-use symmetric keys for temporary communications during an online session

Steganography

process of hiding messages

Cryptography

process of making and using codes to secure information

Cryptanalysis

process of obtaining the plaintext message from a ciphertext message without knowing the keys

Nonrepudiation

process of verifying that a message was sent by the sender and thus cannot be refuted

Digital certificates

public-key container files that allow PKI system components and end users to validate a public key and identify its owner

Polyalphabetic substitution

substitution cipher that incorporates two or more alphabets in the encryption process

Monoalphabetic substitution

substitution cipher that only incorporates a single alphabet in the encryption process

Vernam cipher

this cipher uses a set of characters for encryption operations only one time and then discards it

Cipher

transformation of the individual components of an unencrypted message into encrypted components

Ciphertext

unintelligible encrypted message resulting from an encryption

Message digest

value representing the application of a hash algorithm on a message that is transmitted with the message so it can be compared with the recipient's locally calculated hash of the same message