Collatz encryption tool

This script is a proof of concept and therefore has not been tested for safety. It is not advised to use this for proper encryption purposes.

Utilizing collatz iteration, this CLI tool can encrypt and decrypt ASCII files with or without a custom passkey.

Table of Contents

Installing

• On Linux
• On Windows
• Uninstalling on Linux

Usage

• Flag usage

Concept

Installing

On Linux

Run the provided install.sh script. Give the install script execute permissions by running chmod +x ./install.sh in the current directory.

On Windows

On Windows run python3 colcipher.py through PowerShell in the current directory.

Uninstalling on Linux

Run sudo ~/.local/share/colcipher/uninstall.sh

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Usage

Simplest way to use colcipher is to encode text directly by running

colcipher "Some text"

This will output 889 26 388 13 287 87 15 14 53 23 and exit.

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Flag usage

Available options are:

-t, --text        Reads text from next command-line argument as input
-f, --file        Takes input from file and outputs to file
-o, --output      Output to file and choose file name
-e, --encrypt     Encrypt input
-d, --decrypt     Decrypt input
-k, --key         Choose custom key for encryption or decryption
-s                Output to console instead of file.
-h, --help        Print this text and exit

Flags can be used in any order.

The -t, -f, -o and -k options all require second arguments right after them, otherwise their usage is invalid and will result in unwanted behaviour.

Examples:

colcipher -t "Some text."
colcipher -f input.txt -o encoded.txt
colcipher -t "Custom key test" -k 293569

NOTE: If a custom passkey is not provided, one is derived from the sum of the ASCII values of the plaintext itself and is inserted as the first number in the ciphertext. If a custom passkey is provided, it is not saved in the ciphertext. The custom key must be an integer larger than 0.

The -e, -d, -s and -h flags are standalone flags requiring no additional arguments. These are basically switches for customizing the behaviour and handling of input and output.

Examples:

colcipher -d -t "889 26 388 13 287 87 15 14 53 23" -o decoded.txt
colcipher -d -f encoded.txt -s
colcipher -e -f ~./somedir/plain.txt -s
colcipher --help

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Concept

The encoding/encryption algorithm works by generating numbers using the iterative function from the famous Collatz Conjecture, the key, whether custom or derived from the plaintext, is the starting number from which iteration starts.

$$ Collatz\ iteration\newline $$

$$ if\ \ 2{\mid}n\ \ then\ \ {n=3n+1}\newline $$

$$ if\ \ 2{\nmid}n\ \ then\ \ {n=\frac{n}{2}} $$

When iteration reaches the 4, 2, 1 loop, the algorithm moves to the next number and continues iterating, thus generating numbers to work with.

Using these numbers, the tool finds numbers whose remainder after dividing by 128 is the ASCII value of our given plaintext character and records how many collatz iterations it took to get to that number from the starting number. After finding the first number for our first character, the iteration counter is reset to 0 and counting begins again until our second number is found. This is repeated until our entire plaintext is exhausted. The collection of number of iterations it takes to get to each correct number is the final ciphertext.