Cybersecurity Cryptography
Diffie-Hellman
A cryptographic algorithm that combines both symmetric and asymmetric encryption to ensure confidentiality and integrity
Polybius Square
Also known as ______checkerboard. A device invented by ancient Greeks. Generally uses 5 rows and 5 columns. Words represented by numbered pairs
Cipher
An algorithm used to encrypt and decrypt text.
Digital signature
Asymmetric encryption that stamps the message using a private key. Allows recipient to know the message came from you
What did Alan Turing do /Alan turing
Cracked the Enigma code
RSA
Developed by Rivest, Shamir, & Adleman. Asymmetric encryption. The "s" in https indicates RSA encryption
Machine that's an example of symmetric encryption
Enigma machine
what did Tim Berners-Lee do /Tim Berners-Lee
Invented the World Wide Web
Morse Code
Invented using electricity to send a series of short and long changes in electrical current across long distances through wires
Disadvantages of symmetric encryption
Key space becomes massive, keeping all the keys secret
Asymmetric key encryption
Public key encryption method. Keys are large prime numbers
Disadvantages of asymmetric encryption
Relatively slow because of complex computations
Private encryption key
Sender and receive share a single private key. Also called shared key or symmetric key encryption. Same key is used in encryption and decryption
Elements needed for symmetric encryption
Shared key, message, encryption algorithm
Advantages of symmetric encryption
Simple (uses only 1 key), fast
Advantages of asymmetric encryption
Smaller key space, more secure because of private keys, can be used for encrypting and signing a message
Cryptography
The science and art of delivering a message securely and confidentially
Type of certificates supported by Kelopatra
X.509 (S/MIME) and openPGP
Encryption vs. Digital Signature
You encrypt a file using public key and decrypt using private key. You sign a document using private key and the receive uses the public key to verify
Pigpen Cipher
a geometric simple substitution cipher, which exchanges letters for symbols which are fragments of a grid
Vigenere Cipher
a method of encrypting text by applying a series of Caesar ciphers based on the letters of a keyword. A square arranged with letters of the alphabet
Mathematical one way function
a one way function is easy to do but hard to undo
Ceasar Cipher
a technique for encryption that shifts the alphabet by some number of characters
Plaintext
original message before it is encrypted
What did donald knuth do /donald knuth
prominent computer scientist, "father of the analysis of algorithms", author of "The Art of Programming" and important multi-volume encyclopedia of algorithms
Decryption
reverses the process of encryption to restore plaintext
Public key encryption
·Uses two keys, a public key available to everybody and a private key belonging to an owner
Digital certificate file
·contains a public key and metadata such as name, time of creation, key validity
How asymmetric encryption works
Uses both a public (encrypt) and private (decrypt) key
Examples of symmetric encryption
Vigenere, Enigma
Algorithm
A set of steps to accomplish a task. Can be expressed in many different notations. The way computers process data.
Railfence Cipher
A type of transposition cipher that encodes the message by splitting it over rows using a wave type pattern
Ciphertext
The encrypted message generated by a cipher
Steganography
The practice of concealing messages or information within other data such as text or images
What did john von neumann do /john von neumann
Virtually all contemporary computer designs are based on concepts developed by him. Computer instructions and data are stored in the same memory (___ ______ architecture)
The bombe machine
This machine was an electromechanical device used by British cryptologists to help decipher German Enigma-machine-encrypted secret messages during World War II
Symmetric key encryption (symmetric encryption)
Type of private key encryption method where sender and receiver share a single private key
Kleopatra
Used to develop and manage certificates