🔐 StegoCrypt Web App

Image • Audio • Text Encryption & Steganography Tool

A Flask-based web application that enables secure text encryption, image steganography, and image–audio transformation using cryptographic techniques.

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🚀 Features

• 🔑 Text Encryption / Decryption (Fernet + SHA-256)
• 🖼️ Hide text inside images (LSB Steganography)
• 🔍 Extract hidden messages from images
• 🔊 Convert images to audio
• 🔁 Recover images from audio
• 🔐 Keyword-based secure transformations

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🏗️ System Architecture

flowchart TD
    A[User Input] --> B[Flask App]
    B --> C{Mode Selection}

    C -->|Text Encrypt| D[Encrypt Text]
    C -->|Text Decrypt| E[Decrypt Text]

    C -->|Image Encrypt| F[Hide Text in Image]
    C -->|Image Decrypt| G[Extract Text from Image]

    C -->|Audio Encrypt| H[Image → Audio]
    C -->|Audio Decrypt| I[Audio → Image]

    D --> J[Output]
    E --> J
    F --> J
    G --> J
    H --> J
    I --> J

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🔐 Encryption Workflow

flowchart LR
    A[Keyword] --> B[SHA-256 Hash]
    B --> C[Base64 Key]
    C --> D[Fernet Encryption]
    D --> E[Encrypted Data]

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🖼️ Image Steganography (LSB)

flowchart TD
    A[Input Image] --> B[Convert to Pixels]
    B --> C[Encrypt Text]
    C --> D[Convert to Binary]
    D --> E[Embed in LSB]
    E --> F[Save Image]

    F --> G[Extract LSB]
    G --> H[Binary → Text]
    H --> I[Decrypt Text]

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🔊 Image ↔ Audio Conversion

flowchart TD
    A[Image] --> B[Flatten Pixels]
    B --> C[Normalize Values]
    C --> D[Convert to Audio Wave]
    D --> E[Save WAV]

    E --> F[Load Audio]
    F --> G[Denormalize]
    G --> H[Reshape using Shape File]
    H --> I[Recovered Image]

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📁 Project Structure

project/
│
├── static/
│   └── uploads/
│
├── templates/
│   ├── base.html
│   ├── index.html
│   ├── tool.html
│   ├── about.html
│   ├── guide.html
│   └── donate.html
│
├── app.py
├── requirements.txt
└── README.md

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⚙️ Installation

git clone https://github.com/your-username/stegocrypt.git
cd stegocrypt

python -m venv venv
source venv/bin/activate      # Linux/Mac
venv\Scripts\activate         # Windows

pip install -r requirements.txt

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▶️ Run the App

python app.py

Open in browser:

http://127.0.0.1:5000/

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🛠️ Usage

🔑 Text Encryption

• Go to: /tool/text-encrypt
• Enter text + keyword

🔓 Text Decryption

• Go to: /tool/text-decrypt

🖼️ Hide Text in Image

• Upload image + message + keyword
• Download encrypted image

🔍 Extract Hidden Text

• Upload encoded image + keyword

🔊 Image → Audio

• Upload image
• Download .wav + .npy

🔁 Audio → Image

• Upload .wav + .npy
• Enter keyword → recover image

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🔐 Security Details

• Hashing: SHA-256
• Encryption: Fernet (symmetric)
• Steganography: LSB encoding
• Key Derivation: Keyword → Hash → Key

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⚠️ Limitations

• Message size limited by image capacity
• Shape file required for audio decoding
• Incorrect keyword = decryption failure
• Large files may impact performance

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🧰 Tech Stack

• Backend: Flask
• Libraries:
  • cryptography
  • numpy
  • opencv-python
  • pillow
  • scipy

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💡 Future Enhancements

• 🔐 User authentication
• ☁️ Cloud storage (AWS S3)
• 📡 API endpoints
• 🎨 Drag & drop UI
• 🤖 AI-based image optimization

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🤝 Contributing

fork → clone → create branch → commit → push → PR

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📜 License

MIT License

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👨‍💻 Author

Adit Sharma