Encryption Decryption using Image Steganography

In the digital age, securing sensitive information during transmission is critical. SecretPixel is an advanced image steganography application that embeds and extracts secret messages within digital images using the Discrete Cosine Transform (DCT) technique. This project leverages the robustness of DCT-based steganography to ensure hidden messages remain undetectable while preserving the visual integrity of the carrier image. The system provides a secure, user-friendly platform for encrypting and decrypting messages, making it ideal for secure communication, data hiding, and digital watermarking applications. The application features a Flask-based backend for image processing and a responsive frontend built with HTML, CSS, and JavaScript. Users can upload images, input a security code, and embed text messages into the image using DCT coefficients in the luminance channel of the YCbCr color space. The security code is hashed using SHA-256 to enhance confidentiality. During decryption, the system extracts the hidden message by reversing the embedding process, ensuring only users with the correct security code can access the data. Key features include support for common image formats (PNG, JPEG), a 16MB file size limit, and automatic cleanup of temporary files to optimize storage. Robust error handling and validation mechanisms ensure reliability and security. Experimental results demonstrate the effectiveness of the DCT-based approach in maintaining image quality while securely embedding messages. SecretPixel offers a practical solution for secure data transmission, with applications in cybersecurity, digital forensics, and confidential communication. Its intuitive interface and efficient processing make it accessible to both technical and non-technical users.