Module 4 Flashcards
Cryptography
Cryptography
The process of converting data into unintelligible form to ensure confidentiality, integrity, and authentication.
Plaintext
The original message that needs to be protected.
Ciphertext
The scrambled message produced after encryption.
Encryption Function
A function that transforms plaintext into ciphertext using a key.
Decryption Function
A function that transforms ciphertext back into plaintext.
Symmetric Encryption
An encryption method where the same key is used for both encryption and decryption.
Asymmetric Encryption
An encryption method where two different keys (public and private) are used for encryption and decryption.
Brute-Force Attack
An attack where all possible keys are tried on a ciphertext until the correct one is found.
Caesar Cipher
A classical cipher where each letter in the plaintext is shifted by a fixed number of positions in the alphabet.
Vigenère Cipher
A polyalphabetic substitution cipher where the letters are shifted by different amounts based on a repeating key.
Block Cipher
A cipher that encrypts blocks of plaintext at a time rather than one bit or byte at a time.
Stream Cipher
A cipher where encryption is done one bit or byte at a time, often using XOR operations.
Diffie-Hellman Key Exchange
A key exchange algorithm that allows two users to agree on a shared secret key without using a secure channel.
RSA
An asymmetric cryptosystem used for encrypting messages and digital signatures, based on the difficulty of factoring large integers.
Digital Signature
A cryptographic mechanism used to ensure the authenticity of a message by allowing the sender to sign the message with a private key.
