image-stego

About

An Image Steganography (hiding/encoding information(text) in an image) web app.

Frameworks used:

• React Js
• Material UI Framework

Working Diagram

LSB based Image steganography

LSB-Steganography is a steganography technique in which we hide messages inside an image by replacing Least significant bit of image with the bits of message to be hidden.As the LSB is only changed, the human eys cannot detect the changes in it.

Encryption Algorithm

• Begin
• Input: Cover_Image, Secret_Message ;
• Transfer Secret_Message into Text;
• Convert Text to Binary_Codes;
• Set BitsPerUnit to Zero;
• Encode Message to Binary_Codes;
• Add by 2 unit for bitsPerUnit;
• Output: Stego_Image;
• End

Decryption Algorithm

• Begin
• Input: Stego_Image
• Calculate BitsPerUnit;
• Decode All_Binary_Codes;
• Shift by 2 unit for bitsPerUnit;
• Convert Binary_Codes to Text;
• Open Text;
• Output Secret_Message;
• End

Function used in steganography.js to encode the message

  
  // Encodes message using LSB method
  function encodeMessage(colors, message) {
    let messageBits = getBitsFromNumber(message.length);
    messageBits = messageBits.concat(getMessageBits(message));
    let history = [];
    let pos = 0;
    while (pos < messageBits.length) {
      let loc = getNextLocation(history, colors.length);
      colors[loc] = setBit(colors[loc], 0, messageBits[pos]);
      while ((loc + 1) % 4 !== 0) {
        loc++;
      }
      colors[loc] = 255;
      pos++;
    }
  };

Function used in steganography.js to decode the message


  // Decodes message from the image
  function decodeMessage(colors) {
    let history = [];
    let messageSize = getNumberFromBits(colors, history);
    if ((messageSize + 1) * 16 > colors.length * 0.75) {
      return '';
    }
    if (messageSize === 0) {
      return '';
    }
    let message = [];
    for (let i = 0; i < messageSize; i++) {
      let code = getNumberFromBits(colors, history);
      message.push(String.fromCharCode(code));
    }
    return message.join('');
  };

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Contributions

Contributions are what make the open source community such an amazing place to be learn, inspire, and create. Any contributions you make are greatly appreciated. To get this project, Follow the steps (It's Open and free :P )

1. Fork the Project

2. Clone the project git clone https://github.com/yourrepo/image-stego.git
After cloning, Setup the local machine with requirements
• Enter npm i to install the required modules
• Enter npm start to run the project locally
3. Create your Feature Branch git checkout -b feature/changedFeature

4. Commit your Changes git commit -m 'Add some AmazingFeature'

5. Push to the Branch git push origin feature/changedFeature

6. Open a Pull Request



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License

Licensed under the MIT License.

This project was a part of FOSS OpenHack '20: https://openhack.gitbook.io/openhack-20/.