Can I use encryption to secure my email communication?
Is the encryption available to enterprise-level only, or can individuals also use it to protect emails
Let’s explore answers to these burning questions here.
According to Verizon 2021 Data Breach Investigations Report, a phishing email is the most common technique for the vast majority to hack cloud-based email servers. The Business Email Compromises (BECs) are the second most used tactic to deploy social engineering scams. In such circumstances, both businesses and individual users must know how to protect their email communication. For incoming emails, you can use various security tools to filter out the malicious emails and be vigilant not to open or download anything malicious. But what about the security of the outgoing emails? You must have a clear idea of how to send encrypted email messages to prevent data leaks, breaches, eavesdropping, and data theft.
In this article, we will discuss the two most common email encryption types, provide links to important resources, and inform you whether a particular technic is limited for only organizations or individuals can use it too to encrypt an email before sending it.
Is it Possible to Encrypt an Email Before Sending it?
You can encrypt an email with two main methods.
1) Transport layer security (TLS)
2) End-to-end encryption (E2E)
Let’s understand both of them in brief and whether they are available for individuals or enterprises.
1) TLS Encryption
Transport layer security encrypts the email while it is in transit. It makes a secure tunnel between two email endpoints, so that no one can intercept the email communication.
Key points
- Most email clients like Gmail, Yahoo, Hotmail, etc., install an SSL/TLS certificate to get transport layer security. Users don’t need to install or take any additional actions manually to encrypt emails with TLS encryption.
- TLS certificates doesn’t encrypt stored emails, i.e., at-rest. It secures data in transit only. So, once the email is delivered to the recipient, the job of TLS security ends there. If an attacker breaks into the email client, they can read all the store communication.
- Email client becomes the mediator. Email clients don’t provide end-to-end security by default. That means the email reaches the service provider's server first, and then it is redirected to the recipients. The email clients store cryptographic keys on their servers. That means their employee can intercept and read your communication if they want.
- An approx. cost for SSL/TLS certificate ranges from $5 to $700 per year.
Summary of How to Send an Encrypted Email Using TLS Technology:You don’t have to do anything manually to use TLS. If your email client has installed an SSL/TLS certificate, your emails are automatically protected with TLS encryption.
2) End-to-End (E2E) Encryption
If you are looking for the best ways to encrypt an email, you might be referring to sending emails with E2E. End-to-end technology is an extra, enhanced security layer over TLS. It protects emails at rest, as well as in transit. The email is directly delivered to recipient, without the email service provider becomes a mediator.
Hashing: Some E2E service providers also hashing. That means the email content gets hashed with a mathematical algorithm and reduced to a fixed size. If anyone tries to alter its contents, the hash value changes the recipient immediately gets notified before it’s too late.
Digital signature: The sender can input the digital signature with all outgoing emails. This signature can’t be copied, removed, or tampered with. It gives the recipient assurance that the email is coming from the source it claims to be.
Other facilities: Many of the E2E service providers give facilities like getting email delivering notification, enabling passwords for opening an email, setting expiration date, disabling forwarding, revoking access to messages, and adding watermark attachments.
How to Send an Encrypted Email Using End-to-End Technology?
These are three popular ways to send emails with E2E technology.
- Email Signing Certificates
- Email clients providing default E2E technology
- Third-party tools/extensions
Let’s explore all of these in detail.
1) Email Signing Certificates
Email signing certificates are also known as S/MIME certificates and email encryption certificates. Companies purchase S/MIME certificates from third-party providers known as a certificate authority (CA).
- These certificates are available at the enterprise level only. Individual users can’t buy and use them.
- The CA conducts a validation process before issuing a certificate.
- You need to buy and install a separate email signing certificate for each employee device.
Check out these resourse links to understand basic requirements and installation steps for an email signing certificate.
- Gmail: (Only G Suite Enterprise and G Suite Enterprise for Education users can install S/MIME certificate through Google search console)
- iPhone and Mac Devices
- Outlook
- Yahoo Mail (You need third-party applications or extensions to enable S/MIME on Yahoo, as it doesn’t accept S/MIME certificates by default).
2) Email Service Providers
These are some popular email clients that provide end-to-end encryption facilities to their users. Unlike S/MIME certificates, these services are available to all the individual users as well.
ProtonMail: For a free account, you’ll get an email ID with @protonmail.com and 500 MB space for your account. If you are a business organization that needs email IDs with their domain name, you need to upgrade to the premium plan. Here’s you can make custom domain [email protected] and get more inbox space with many other benefits.
Tuanota: Same as ProtonMail, but it has more variety of plans and some extra features, like 2FA, encrypted email subject lines, etc. Individual users can use its free service with Tuanota’s domain and 1 GB of storage. Businesses can choose a more customized plan as per their requirement.
Mailfence: Same features as above two. Free account for individuals and paid service for businesses that need email IDs with custom domains.
3) Third-party Plugins/ Extensions
These are some freemium plugins/browser add-ons or extensions you can install on your regular email clients to get end-to-end encryption. This option is also available for both individuals and enterprises. They are based on open Pretty Good Privacy (PGP).
Final Words on How to Encrypt an Email
If you are an individual that doesn’t send highly confidential information on emails, TLS security is enough for you. But if you are sending sensitive documents, financial information, or personally identifiable information (PII) on email, you can opt for E2E security. For enterprises, it is crucial to use the E2E protocol because businesses are frequently subject to data theft, phishing, and spoofing attacks. For that, you can either make a free account on the above-stated email clients or install the browser extensions. Apart from the above two methods, you can also opt for email signing certificates. They cost less and provide way more benefits than other options.
With digitization, everyone has a personal email ID with their financial records, assets, images, social media profiles, and several other important documents saved online.
And, securing this email from all-round online threats can be a huge challenge.
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