Basic cipher info 🢃1

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Basic Ciphers

Plaintext: the decoded, legible text of a message
Ciphertext: the encoded, illegible text of a message
Key: a variable value that is used to encode plaintext and to decode ciphertext
Caesar Cipher: a cipher that works by shifting letters through the alphabet
Brute-forcing: guessing many different passwords or key values

Basic Computing

Base: a system of counting
Decimal (base 10): uses digits 0-9
Binary (base 2): uses digits 0 and 1
Octal (base 8): uses digits 0-7
Hexadecimal (base 16): uses digits 0-9 and A-F
ASCII: a standardized method of converting numbers to plaintext characters, and vice versa
Converting binary, octal, decimal, or hexadecimal into ASCII:
Convert the numbers into base 10
Turn the base 10 numbers into plaintext by checking them against an ASCII table

Basic Webpages

If an ARG leads to a website, always check the page source!
HTML: a language used to create webpages
HTML tags: indicate how HTML should be read by your browser
Comments: text which is not displayed on a page, which can be used to conceal information
CSS: a language used to add style to HTML pages
Javascript: a programming language used in HTML pages

Boolean Operators

Boolean Operations: Operations performed on binary numbers
NOT Operation: flips all the bits of a binary number
AND Operation: compares 2 binary numbers; if both bits are 1, then the result is 1, otherwise the result is 0
OR Operation: compares 2 binary numbers; if either is 1, then the result is 1, otherwise the result is 0
XOR Operation: compares 2 binary numbers; if each bit is different, the result is 1, and if the bits are the same, the result is 0
XOR Cipher: a cipher that uses XOR operation with a key value

Vigenere Cipher: a cipher that uses a repeating keyword, and is comprised of many small Caesar ciphers
Vigenere Table: a table that can be used to quickly encode or decode a Vigenere cipher
Rolling-Key Cipher: a cipher identical to a Vigenere cipher, except the key is long enough that it does not need to repeat
Autokey Cipher a Vigenere/rolling-key cipher that incorporates the plaintext into its key