CH 5: Sequences - Strings, Lists, and Files

ASCII

American Standard Code for Information Interchange; a standard for encoding text where each character is represented by a number 0-127

public key

a form of encryption that uses two different keys; a message encoded with a public key can only be decoded using a separate private key

private key

a kind of encryption where the same key is used to both encrypt and decrypt and must therefore be kept a secret

batch

a mode of processing in which input and output is done through files rather than interactively

substring

a sequence of contiguous characters inside a string

unicode

an alternative to ASCII that encodes characters from virtually all of the world's written languages

mutable

changeable

slicing

extracting a subsequence of a string, list, or other sequence object

indexing

selecting a single item from a sequence based on its relative position in the sequence

control codes

special characters that do not print, but are used in the interchange of information

ciphertext

the encrypted form of a message

open

the process of associating a file in secondary memory with a variable in a program through which the file can manipulated

encryption

the process of encoding information to keep it private

cryptography

the study of techniques for encoding information to keep it secure

cipher alphabet

the symbols that are used to encrypt a message

plaintext

the unencoded message