Mitigating eMail Attacks: GnuPG (en)

This module will guide you step by step in securing your email communications using GnuPG (GNU Privacy Guard) encryption in the Thunderbird email client. GnuPG is a powerful and free encryption tool, while Thunderbird is a popular open-source email client. By combining the two, you can protect sensitive information that you send and receive via email from unauthorized parties.

Module Objectives

Understand the basic concepts of asymmetric cryptography and GnuPG.
Create PGP (Pretty Good Privacy) keys and manage the keyring.
Configure Thunderbird to use GnuPG encryption.
Send and receive encrypted emails.
Verify message integrity with digital signatures.

Prerequisites

A computer with an installed operating system (Windows, macOS, or Linux).
Thunderbird email client installed.
A stable internet connection.

Steps

Installing GnuPG and Thunderbird

GnuPG: Download and install GnuPG from the official website ([1](https://gnupg.org/)). Follow the installation instructions provided.
Thunderbird: GnuPG is currently a built-in add-on for Thunderbird that facilitates the use of GnuPG.

Creating PGP Keys

Open the GnuPG application or use the Thunderbird interface to create a PGP key pair.
Choose an appropriate key length (minimum of 2048 bits) and enter a strong passphrase. This passphrase is crucial for protecting your private key.
Store your private key in a safe place. The public key can be shared with others who wish to communicate with you securely.

Configuring Thunderbird

After installing Thunderbird, configure general settings such as keyring location and encryption preferences.
Import the public keys of others you wish to send encrypted emails to.

Sending Encrypted Emails

When composing a new email, enable the encryption option in Thunderbird.
Select the recipient and choose their public key to encrypt the message.
Write your message and send it.

Receiving and Decrypting Emails

When receiving an encrypted email, Thunderbird will automatically prompt you for your passphrase to decrypt the message.
Enter the correct passphrase, and the message will be decrypted.

Verifying Digital Signatures

In addition to encryption, GnuPG also supports digital signatures to verify the sender's identity.
Thunderbird will display information about the digital signature when you open a signed email.

Practical Exercises

Exercise 1: Create your own PGP key pair and share your public key with a friend or family member.
Exercise 2: Send an encrypted email to a friend or family member who has your public key.
Exercise 3: Verify the digital signature on an email you received.

Interesting Links

Forensic: IT
GnuPG Documentation: [2](https://gnupg.org/documentation/)
Thunderbird Documentation:
Basic Concepts of Cryptography: Briefly explain symmetric and asymmetric cryptography, as well as the role of public and private keys in GnuPG.
Security Best Practices: Provide security tips such as choosing a strong passphrase, protecting your private key, and avoiding phishing.
Advanced Usage: Explain advanced Thunderbird features like creating digital signatures, file encryption, and keyring management.