Step 1.a Set up your email program with your email account

Open your email program and follow the wizard (step-by-step walkthrough)that sets it up with your email account. This usually starts from "Account Settings" → "Add Mail Account". You should get the email server settings from your systems administrator or the help section of your email account.

Step 1.b Install GnuPG

If you are using a GNU/Linux machine, you should already have GnuPG installed, and you can skip toSection 2.

If you are using a macOS or Windows machine, however, you need to first install the GnuPG program. Select your operating system below and follow the instructions. For the rest of this guide, the steps are the same for all operating systems.

GnuPG, OpenPGP, what?

In general, the terms GnuPG, GPG, GNU Privacy Guard, OpenPGP and PGPare used interchangeably. Technically, OpenPGP (Pretty Good Privacy) is theencryption standard, and GNU Privacy Guard (often shortened to GPG or GnuPG)is the program that implements the standard. Most email programs provide an interface for GnuPG. There is also a newer version of GnuPG, called GnuPG2.

Step 2.a Make a keypair

Make your keypair

We will use the command line in a terminal to create a keypair using theGnuPG program.

Whether on GNU/Linux, macOS or Windows, you can launch yourterminal ("Terminal" in macOS, "PowerShell" in Windows) from the Applicationsmenu (some GNU/Linux systems respond to theCtrl + Alt + Tshortcut).

# Entergpg --full-generate-key to start the process.

# To answer what kind of key you would like to create, select the default option:1 RSA and RSA.

# Enter the following keysize:4096 for a strong key.

# Choose the expiration date; we suggest2y (2 years).

Follow the prompts to continue setting up with your personal details.

Depending on your version of GPG, you may need to use--gen-key instead of--full-generate-key.

You can set further options by runninggpg --edit-key [your@email] in aterminal window.

Set your passphrase

On the screen titled "Passphrase," pick a strong passphrase! You cando it manually, or you can use the Diceware method. Doing it manuallyis faster but not as secure. Using Diceware takes longer and requiresdice, but creates a passphrase that is much harder for attackers to figureout. To use it, read the section "Make a secure passphrase with Diceware" inthis article by Micah Lee.

If you'd like to pick a passphrase manually, come up with somethingyou can remember which is at least twelve characters long, and includesat least one lower case and upper case letter and at least one number orpunctuation symbol. Never pick a passphrase you've used elsewhere. Don't useany recognizable patterns, such as birthdays, telephone numbers, pets' names,song lyrics, quotes from books, and so on.

Step 2.b Some important steps following creation

Upload your key to a keyserver

We will upload your key to a keyserver, so if someone wants to send you an encrypted message, they can download your public key from the Internet. There are multiple keyserversthat you can select from the menu when you upload, but they are mostly all copiesof each other. Any server will work, but it's good to remember which one you uploaded your key to originally. Also keep in mind, sometimes takes a few hours for them to match each other when a new key is uploaded.

# Copy your keyID:gpg --list-key [your@email] will list your public ("pub") key information, including your keyID, which is a unique list of numbers and letters. Copy this keyID, so you can use it in the following command.

# Upload your key to a server:gpg --send-key [keyID]

Export your key to a file

Use the following command to export your secret key so you can import it into your email client at the nextstep. To avoid getting your key compromised, store this in a safe place, and make sure that if it is transferred, it is done so in a trusted way. Exporting your keys can be done with the following commands:

$ gpg --export-secret-keys -a [keyID] > my_secret_key.asc
$ gpg --export -a [keyID] > my_public_key.asc

Generate a revocation certificate

Just in case you lose your key, or it gets compromised, you want to generate a certificate and choose to save it in a safe place on your computer for now (please refer toStep 6.C for how to best store your revocation cerficate safely). This step is essential for your email self-defense, as you'll learn more about inSection 5.

# Copy your keyID:gpg --list-key [your@email] will list your public ("pub") key information, including your keyID, which is a unique list of numbers and letters. Copy this keyID, so you can use it in the following command.

# Generate a revocation certificate:gpg --gen-revoke --output revoke.asc [keyID]

# It will prompt you to give a reason for revocation, we recommend to use1 = key has been compromised.

# You don't have to fill in a reason, but you can; then press "Enter" for an empty line, and confirm your selection.

Step 3.a Set up your email with encryption

Once you have set up your email with encryption, you can start contributing to encrypted traffic on the Internet. First we'll get your email client to import your secret key, and we will also learn how to get other people's public keys from servers so you can send and receive encrypted email.

# Open your email client and use "Tools" →OpenPGP Key Manager

# Under "File" →Import Secret Key(s) From File

# Select the file you saved under the name [my_secret_key.asc] inStep 2.B when you exported your key

# Unlock with your passphrase

# You will receive a "OpenPGP keys successfully imported" window to confirm success

# Go to "Account settings" → "End-To-End Encryption," and make sure your key is imported and selectTreat this key as a Personal Key.

Step 4.a Send Edward your public key

This is a special step that you won't have to do when correspondingwith real people. In your email program's menu, go to "Tools" → "OpenPGP KeyManager." You should see your key in the list that pops up. Right clickon your key and selectSend Public Keys by Email. This will create a new draft message, as if you had just hit the "Write" button, but in the attachment you will find your public keyfile.

Address the message toedward-en@fsf.org. Put at least one word(whatever you want) in the subject and body of the email. Don't send yet.

We want Edward to be able to open the email with your keyfile, so we want this first special message to be unencrypted. Make sure encryption is turned off by using the dropdown menu "Security" and selectDo Not Encrypt. Once encryption is off, hit Send.

It may take two or three minutes for Edward torespond. In the meantime, you might want to skip ahead and check out theUse it Well section of this guide. Once you have received a response,head to the next step. From here on, you'll be doing just the same thing aswhen corresponding with a real person.

When you open Edward's reply, GnuPG may prompt you for your passphrasebefore using your private key to decrypt it.

Step 4.b Send a test encrypted email

Get Edward's key

To encrypt an email to Edward, you need its public key, so now you'll haveto download it from a keyserver. You can do this in two different ways:

Option 1. In the email answer you received from Edward as a response to your first email, Edward's public key was included. On the right of the email, just above the writing area, you will find an "OpenPGP" button that has a lock and a little wheel next to it. Click that, and selectDiscover next to the text: "This message was signed with a key that you don't yet have." A popup with Edward's key details will follow.

Option 2. Open your OpenPGP Key manager, and under "Keyserver" chooseDiscover Keys Online. Here, fill in Edward's email address, and import Edward's key.

The optionAccepted (unverified) will add this key to your key manager, and now it can be used to send encrypted emails and to verify digital signatures from Edward.

In the popup window confirming if you want to import Edward's key, you'll see many different emails that are all associated with its key. This is correct; you can safely import the key.

Since you encrypted this email with Edward's public key,Edward's private key is required to decrypt it. Edward is the only one withits private key, so no one except Edward can decrypt it.

Send Edward an encrypted email

Write a new email in your email program, addressed toedward-en@fsf.org. Make the subject"Encryption test" or something similar and write something in the body.

This time, make sure encryption is turned on by using the dropdown menu "Security" and selectRequire Encryption. Once encryption is on, hit Send.

Important: Security tips

Even if you encrypt your email, the subject line is not encrypted, sodon't put private information there. The sending and receiving addressesaren't encrypted either, so a surveillance system can still figure out whoyou're communicating with. Also, surveillance agents will know that you'reusing GnuPG, even if they can't figure out what you're saying. When yousend attachments, you can choose to encrypt them or not,independent of the actual email.

For greater security against potential attacks, you can turn offHTML. Instead, you can render the message body as plain text. In orderto do this in Icedove or Thunderbird, go to "View" → "Message Body As" →PlainText.

Step 4.c Receive a response

When Edward receives your email, it will use its private key to decryptit, then reply to you.

It may take two or three minutes for Edward torespond. In the meantime, you might want to skip ahead and check out theUse it Well section of this guide.

Edward will send you an encrypted email back saying your email was received and decrypted. Your email client will automatically decrypt Edward's message.

The OpenPGP button in the email will show a little green checkmark over the lock symbol to show the message is encrypted, and a little orange warning sign which means that you have accepted the key, but not verified it. When you have not yet accepted the key, you will see a little question mark there. Clicking the prompts in this button will lead you to key properties as well.

Step 4.d Send a signed test email

GnuPG includes a way for you to sign messages and files, verifying thatthey came from you and that they weren't tampered with along the way. Thesesignatures are stronger than their pen-and-paper cousins -- they're impossibleto forge, because they're impossible to create without your private key(another reason to keep your private key safe).

You can sign messages to anyone, so it's a great way to make peopleaware that you use GnuPG and that they can communicate with you securely. Ifthey don't have GnuPG, they will be able to read your message and see yoursignature. If they do have GnuPG, they'll also be able to verify that yoursignature is authentic.

To sign an email to Edward, compose any message to the email address and click thepencil icon next to the lock icon so that it turns gold. If you sign amessage, GnuPG may ask you for your passphrase before it sends the message,because it needs to unlock your private key for signing.

In "Account Settings" → "End-To-End-Encryption" you can opt toadd digital signature by default.

Step 4.e Receive a response

When Edward receives your email, he will use your public key (whichyou sent him inStep 3.A) to verify the messageyou sent has not been tampered with and to encrypt a reply to you.

It may take two or three minutes for Edward torespond. In the meantime, you might want to skip ahead and check out theUse it Well section of this guide.

Edward's reply will arrive encrypted, because he prefers to use encryptionwhenever possible. If everything goes according to plan, it should say"Your signature was verified." If your test signed email was also encrypted,he will mention that first.

When you receive Edward's email and open it, your email client willautomatically detect that it is encrypted with your public key, andthen it will use your private key to decrypt it.

Step 5.a Sign a key

In your email program's menu, go to OpenPGP Key Manager and selectKey properties by right clicking on Edward's key.

Under "Your Acceptance," you can selectYes, I've verified in person this key has the correct fingerprint.

You've just effectively said "I trust that Edward's publickey actually belongs to Edward." This doesn't mean much because Edward isn'ta real person, but it's good practice, and for real people it is important. You can read more about signing a person's key in thecheck IDs before signing section.

Identifying keys: Fingerprints and IDs

People's public keys are usually identified by their key fingerprint,which is a string of digits like F357AA1A5B1FA42CFD9FE52A9FF2194CC09A61E8(for Edward's key). You can see the fingerprint for your public key, andother public keys saved on your computer, by going to OpenPGP KeyManagement in your email program's menu, then right clicking on the keyand choosing Key Properties. It's good practice to share your fingerprintwherever you share your email address, so that people can double-check thatthey have the correct public key when they download yours from a keyserver.

You may also see public keys referred to by a shorterkeyID. This keyID is visible directly from the Key Managementwindow. These eight character keyIDs were previously used foridentification, which used to be safe, but is no longer reliable. Youneed to check the full fingerprint as part of verifying you have thecorrect key for the person you are trying to contact. Spoofing, inwhich someone intentionally generates a key with a fingerprint whosefinal eight characters are the same as another, is unfortunatelycommon.

Important: What to consider when signing keys

Before signing a person's key, you need to be confident that it actuallybelongs to them, and that they are who they say they are. Ideally, thisconfidence comes from having interactions and conversations with them overtime, and witnessing interactions between them and others. Whenever signinga key, ask to see the full public key fingerprint, and not just the shorterkeyID. If you feel it's important to sign the key of someone you've justmet, also ask them to show you their government identification, and makesure the name on the ID matches the name on the public key.

When should I encrypt? When should I sign?

The more you can encrypt your messages, the better. If you only encryptemails occasionally, each encrypted message could raise a red flag forsurveillance systems. If all or most of your email is encrypted, peopledoing surveillance won't know where to start. That's not to say that onlyencrypting some of your email isn't helpful -- it's a great start and itmakes bulk surveillance more difficult.

Unless you don't want to reveal your own identity (which requires otherprotective measures), there's no reason not to sign every message, whether ornot you are encrypting. In addition to allowing those with GnuPG to verifythat the message came from you, signing is a non-intrusive way to remindeveryone that you use GnuPG and show support for secure communication. If youoften send signed messages to people that aren't familiar with GnuPG, it'snice to also include a link to this guide in your standard email signature(the text kind, not the cryptographic kind).

Be wary of invalid keys

GnuPG makes email safer, but it's still important to watch out for invalidkeys, which might have fallen into the wrong hands. Email encrypted withinvalid keys might be readable by surveillance programs.

In your email program, go back to the first encrypted email that Edwardsent you. Because Edward encrypted it with your public key, it will have agreen checkmark on the "OpenPGP" button.

When using GnuPG, make a habit of glancing at that button. The programwill warn you there if you get an email signed with a key that can'tbe trusted.

Copy your revocation certificate to somewhere safe

Remember when you created your keys and saved the revocation certificatethat GnuPG made? It's time to copy that certificate onto the safest storage that you have -- a flash drive, disk, or hard drive stored in a safe place in your home could work, not on a device you carry with you regularly. The safest way we know is actually to print the revocation certificate and store it in a safe place.

If your private key ever gets lost or stolen, you'll need this certificatefile to let people know that you are no longer using that keypair.

IMPORTANT: ACT SWIFTLY if someone gets your private key

If you lose your private key or someone else gets a holdof it (say, by stealing or cracking your computer), it'simportant to revoke it immediately before someone else usesit to read your encrypted email or forge your signature. Thisguide doesn't cover how to revoke a key, but you can follow theseinstructions.After you're done revoking, make a new key and send an email to everyonewith whom you usually use your key to make sure they know, including a copyof your new key.

Webmail and GnuPG

When you use a web browser to access your email, you're using webmail,an email program stored on a distant website. Unlike webmail, your desktopemail program runs on your own computer. Although webmail can't decryptencrypted email, it will still display it in its encrypted form. If youprimarily use webmail, you'll know to open your email client when you receivea scrambled email.

Make your public key part of your online identity

First add your public key fingerprint to your email signature, thencompose an email to at least five of your friends, telling them you justset up GnuPG and mentioning your public key fingerprint. Link to this guideand ask them to join you. Don't forget that there's also an awesomeinfographic to share.

Start writing your public key fingerprint anywhere someonewould see your email address: your social media profiles, blog, Website,or business card. (At the Free Software Foundation, we put ours on ourstaff page.) We need to get ourculture to the point that we feel like something is missing when we see anemail address without a public key fingerprint.