A simple Android application for secure text and file encryption and decryption using a hybrid RSA/AES encryption scheme. Encrypt It allows users to encrypt messages and files with a contact's public key so they can decrypt it with their private key, ensuring secure communication and file sharing.

• Hybrid Encryption: Combines RSA (2048-bit) for key exchange and AES/CBC (256-bit) for message encryption.
• Contact Management: Add, remove, and select contacts with their public keys for encryption.
• Key Import/Export: Export and import your public and encrypted private keys to/from a JSON file for backup or transfer.
• Contact Import/Export: Export and import your contact list with their public keys to/from a JSON file.
• Clipboard Integration: Automatically copies encrypted messages to the clipboard for easy sharing.
• Key Persistence: Stores your RSA key pair and contact public keys in SharedPreferences.
• User-Friendly UI: Simple interface with an EditText for messages, buttons for encryption/decryption, and a dropdown for contact selection.
• Encrypted Private Key: The user's private key is encrypted and saved locally. The user must use the same password to decrypt their private key in order to use the app.
• File Encryption and Decryption: Encrypt a file using your contact's public key so that only they can decrypt it with their private key.
• Sign and Verify Messages: Digitally sign your messages with your private key and verify messages from contacts using their public keys.

1. Generate or Load Keys:

   • On first launch, the app generates a 2048-bit RSA key pair and saves it to SharedPreferences.
   • The user will be prompted to set a password to encrypt their private key, and again when opening the app to decrypt the private key.
   • View your public key via Menu > Keys > "Show My Public Key" and share it with contacts.
   • Export your public and encrypted private keys to a JSON file via Menu > Keys > "Export Keys".
   • Import keys from a JSON file via Menu > Keys > "Import Keys" (requires the same password used for encryption).

2. Add Contacts:

   • Menu > Contacts > "Add Contact".
   • Enter a name and paste their RSA public key.
   • Save to store the contact.
   • Export all contacts and their public keys to a JSON file via Menu > Contacts > "Export Contacts".
   • Import contacts from a JSON file via Menu > Contacts > "Import Contacts".

3. Encrypt a Message:

   • Type your message in the text field.
   • Enter the contact name and select it from the dropdown menu.
   • Click "Encrypt" to encrypt the message and copy it to the clipboard.

4. Decrypt a Message:

   • Paste an encrypted message into the text field.
   • Click "Decrypt" to reveal the original text.

5. Manage Contacts:

   • Menu > Contacts > "Remove Contact" to delete contacts from the list.

This project is licensed under the MIT License - see the LICENSE file for details.

Download Encrypt It