Brainfuck

Brain Fuck is not a proper encryption system, but rather a programming language that has been obfuscated. Encoding consists in writing machine code that returns text as output.

Machine operations are:

> : increment the pointer (+1),

< : decrement the pointer (-1),

+ : increment the byte in the memory cell where the pointer is located,

- : decrement the byte in the memory cell where the pointer is located,

. : send the value of the pointed byte as output (treated as an ASCII value),

, : insert an input byte (user input) in the memory cell where the pointer is located (ASCII value),

[ : if the pointed byte is 0 then jump to instruction after the corresponding ],

] : if the pointed byte is not 0 then jump to the instruction after the corresponding [

In order to shorter the code, an alternative syntax exists (shortcut BF) that uses i for increment, d for decrement, r for right, l for left each associated to a number to indicate the repetition of the operation.

Example: i4 (+ 4 times) => ++++ , d3 (- 3 times) => ---, r5 => >>>>>, l4 => <<<<

Once again it is not an decryption but rather an interpretation of the code (or brainfuck translator that turn brainfuck to text). Each byte send as output is then a plain text character.

Replace iX, dX, rX and lX by respectively +, -, >, < X times to get back the original BF code.

The message is composed of the 8 characters ><+-.,[]

The character [ should appear as many times as the character ]

The characters + and - are the most common and usually appear to +++ group or ---. It makes little sense (but possible) to have + and - consecutively.

The characters . and , are less frequent.

Many variant of brainfuck have gave languages such as Spoon or Ook.

Created by Urban Müller in 1993