Algorithms for encryption

Cryptography

Techniques for sending messages securely so that they cannot be read by any third parties.

Cryptographer

Someone who designs algorithms that can easily be used to encrypt and decrypt a cipher but remains secure against attempts to break it.

Code

Changing a message by replacing each word with another word that has a different meaning. Both sender and recipient have to have a copy of the same codebook.

Cipher

Changing a message using an algorithm which changes each letter in a set way. Both sender and recipient need to know the algorithm.

Monoalphabetic Substitution Cipher

A cipher where each letter of the alphabet is changed to one other letter or symbol.

Encryption

Makes data unintelligible by scrambling it. This provides security for the data.

Decryption

The process of converting the scrambled data back into an understandable form

Plaintext

Unencrypted message awaiting encryption.

Ciphertext

The encrypted message that is ready to be sent.

Key

A piece of information that specifies the transformation of plaintext into ciphertext and vice versa

Modulo

A mathematical operation that finds the remainder after division of one number by another - used in some monoalphabetic substitution ciphers.

Brute Force

A method for determining a solution to a problem by sequentially testing all possible solutions.