stegjs

A Node.js module and command-line utility for performing steganographic encoding in PNG images. This application enables the secure transmission of secret messages, passwords, or other critical information by embedding data within images.

Installation

To install globally you should enter in terminal window the following command:

$ npm i -g stegjs

To install locally you should enter in terminal window the following command:

$ npm i stegjs

Help

Usage as Node.js module

const steg = require('stegjs')

// Encode message
const response = steg.encode('img.png', 'my_secret_pass', '1x1', './secrets/go.png')
console.log(response) // -> { message: 'my_secret_pass', pattern: '1x1', output: './secrets/go.png' }

// Decode message
const response = steg.decode('./secrets/go.png')
console.log(response) // -> { message: 'my_secret_pass', pattern: '1x1' }

Usage as CLI

$ stegjs --help

  Usage: stegjs <image or url>.png [mode] [message] [step] [output]

  Encrypt you message to PNG image.

  Options:

    -h, --help     output usage information
    -V, --version  output the version number
    -e, --encode   Change program mode to encode file
    -d, --decode   Change program mode to decode file

Syntax information:

[mode]		one of the two modes
[message]	the message you want to encrypt
[step]		pattern of the distribution message bits in the alpha channel of the image
[output]	path where to save the image with the encoded message

Examples

The program works in two modes, encrypt and decrypt messages.

Encode

To encrypt a message use one of the following commands:

$ npx stegjs img.png -e "Meeting tonight at midnight under the light." 5x5
$ npx stegjs https://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png -e "my_secret_pass" 1x1 ./secrets/go.png
$ npx stegjs nyan.png -e "🐱" 2x1

After that in the console, you will see the full path to the output image, message and pattern.

/Users/you/secrets/out.png has been encoded
message: 🐱
pattern: 2x1

Decode

To receive an encrypted message, specify the path to the image with the secret message and add the flag -d.

$ npx stegjs out.png -d

After that in the console, you will see the information contained in the encrypted image.

out.png was decoded
message: 🐱
pattern: 2x1

License

MIT © Andrey Medvedev