Email Security Basics: 7 Common Protocols You Need to Know

Information on the internet can be handled carelessly and dangerously. Most of your online footprints stem from the emails that you send and receive.

So, it seems evident that our emails should have some security measures set up, but most don’t.

Some are simple enough to be broken and hacked. In this article, we will list some commonly used security protocols and explain how they work.

1. SSL/TLS

SSL and TLS are application layer protocols or rules most commonly used by emails.

Transport Layer Security (TLS) is the successor of SSL, providing base-level encryption.

An email client, such as Gmail, often connects to an email server through TCP while sending and receiving mail.

The TLC adds privacy and security while connecting the client and the server.

2. Digital Certificates

Digital Certificates are used to encrypt your email details using cryptography. They belong to a class called ‘Public Key Encryption.’

Your Digital Certificate is a public key that allows them to lock emails they send you.

You can also decrypt the emails using a private key that will be available to you. This is how Bitcoin works.

3. SPF (Sending Policy Framework)

This protocol authenticates domains and prevents them from being spoofed. Domains can also be used to hide the intents of hackers and cybercriminals.

SPF helps a server identify whether the message was sent via a legitimate domain.

4. DKIM (Domain Keys Identified Mail)

DKIM is an extended version of SPF that protects your email while it’s on the move. It also works in different ways.

First, it uses a digital signature to check if a domain sent the mail. Then, it traces the message back to the domain to see if it is sending it. It is a double-layered protocol.

5. DMARC

DMARC is an acronym for Domain-Based Message Authentication, Reporting, and Conformance.

It’s an authentication protocol that checks the validity of SPF and DKIM and instructs the provider on handling incoming messages.

Although, DMARC has not seen good rates of adoption. And it is not foolproof either.

6. S/MIME

These are end-to-end encryption protocols. S/MIME is specifically designed to encrypt email contents but leaves the details, such as sender and recipient, open.

It has existed for a long time, and your email clients probably use it, too. They demand a digital signature so only the receiver can decrypt your email.

7. PGP (Pretty Good Privacy)

PGP and OpenPGP are two-way encryption protocols, with the second being open-source.

Open Pretty Good Privacy (PGP) works just like S/MIME, meaning only the contents are encrypted. A third party can gather recipient and sender details, which constitute the metadata.

OpenPGP receives timely updates and is free to use. GPGSuite for Mac and Gpg4Win for Windows should be a good place to start.