TextToImage Encrypter (TTi encrypter)

By Anshurup Gupta

This is a Text to image encrypter.

This project is a C-based application that takes a text file containing a normal ASCII message and converts it into a noisy and encrypted PNG image. The encryption is based on the Diffie-Hellman Algorithm (DHA) cryptography. The generated PNG can be decrypted back into the original message using the same algorithm.

Features

• Text to Image Conversion: Convert any text file into a noisy PNG image, making the text unreadable without decryption.
• Encryption: Implements Diffie-Hellman Algorithm (DHA) for secure encryption.
• Decryption: Decrypt the noisy PNG back into the original text using the corresponding decryption key.

Prerequisites

• C Compiler: Ensure you have GCC or any other C compiler installed.
• FreeImageLibrary: Install the FreeImage library for handling PNG files. (present with the project)

File Structure

• data/: Contains the words that are stored in the dictionary.
• decrypt/: Keep your png in this folder to decrypt.
• messages/: Keep your txt in this folder to encrypt.
• Dependencies: Included with the folder.
• Application: TTi.exe
• README.md: This file.

Usage

Converting Text to Noisy Encrypted PNG

• input.txt: The input text file containing the ASCII message.
• output.png: The generated noisy and encrypted PNG image.

Decrypting PNG to Text

• encrypted.png: The noisy and encrypted PNG file.
• decrypted_output.txt: The output text file with the decrypted message.

How It Works

1. Text to PNG:

   • The text from the input file is read and encrypted using the DHA algorithm.
   • Use of a hash map to create linked lists of hashed words based on keys
   • The encrypted text is then encoded into a PNG image with added noise to make it unreadable without the decryption key.

2. PNG to Text:

   • The noisy PNG is decoded to retrieve the encrypted data.
   • The data is then decrypted using the corresponding DHA key to produce the original message.

Contributing

Feel free to submit issues and pull requests. Any contributions, such as new features or bug fixes, are welcome!

Acknowledgments

• Thanks to the authors of the FreeImage library.
• Special thanks to the open-source community for their invaluable resources.
• IIT Patna