E-mail is without doubt one of the most handy communication channels for companies and people, because of its accessibility. However this additionally makes electronic mail inclined to cybercriminals who try and entry delicate knowledge by intercepting emails in transit or hacking into electronic mail servers.
One of many principal strains of protection towards this assault is electronic mail encryption, a extensively used approach to safe the knowledge despatched over electronic mail.
Now, you most likely have a flurry of questions on this matter, like:
- What’s electronic mail encryption?
- How do encrypted emails work?
- Why do you have to encrypt emails?
Learn on to search out the solutions to those and different widespread questions on encryption and learn the way Twilio SendGrid secures emails in transit.
What’s electronic mail encryption?
Before everything, electronic mail encryption scrambles the content material of an electronic mail, changing it into an unreadable format known as ciphertext. As soon as an electronic mail is encrypted, solely a certified person (the recipient) can decrypt it and look at the unique message. Anybody else who tries to intercept the message will solely be capable of see the ciphertext—thus, defending the contents of the e-mail.
How does electronic mail encryption work?
E-mail encryption makes use of cryptographic keys or strings of characters that exchange the unique knowledge to seem random. And in contrast to the straightforward cryptographic keys that individuals can create, electronic mail encryption companies generate keys utilizing complicated algorithms that scramble the info past human recognition.
So how do senders and recipients use these keys to encrypt and decrypt messages? There are 2 methods:
- Symmetric cryptography: The sender and the recipient use a single, non-public key to encrypt and decrypt the message. This implies the sender must share the important thing with the recipient to allow them to decrypt the message.
- Uneven cryptography: The sender makes use of a public key to encrypt the message, then the recipient makes use of a non-public key (that solely they know) to decrypt it. That is also called public-key cryptography, and in contrast to symmetric encryption, the sender and recipient don’t must share the important thing.
Nevertheless, right this moment, probably the most extensively used forms of encryption are likely to depend on a mixture of symmetric and uneven cryptography, as we’ll focus on later.
Why ought to senders encrypt emails?
Earlier than we reply that, let’s begin with a reminder that it is best to by no means ship delicate data, like passwords or Social Safety numbers, over electronic mail.
That mentioned, emails usually include private details about the recipient, like their deal with, or enterprise data not supposed for the general public. And with out encryption, dangerous actors may intercept that data and use it to commit id theft, fraud, and different crimes towards people or companies.
Because of this encryption is so necessary: it ensures that no particular person or entity intercepts the content material of the e-mail alongside the way in which or, in some circumstances, because it sits in electronic mail servers.
Moreover, as a result of legal guidelines just like the Basic Knowledge Safety Laws, regulators can superb companies if prospects’ private knowledge is compromised. Nevertheless, encryption may also help keep away from this.
Lastly, encryption is a vital component of electronic mail safety that may finally influence the sender’s repute and deliverability.
What are the several types of electronic mail encryption?
There are 3 widespread forms of electronic mail encryption used right this moment. Let’s take a look at how these work, plus a safe different for sending extremely delicate data.
TLS
Transport layer safety (TLS) is a protocol that encrypts electronic mail knowledge because it travels from the sender’s electronic mail server to the recipient’s—although it doesn’t encrypt it at its vacation spot. TLS makes use of uneven and symmetric cryptography to encrypt electronic mail knowledge. Meaning it generates and exchanges a session key by means of uneven cryptography, then the sender and recipient use this key to encrypt and decrypt the message.
Many electronic mail suppliers, together with SendGrid, use opportunistic TLS encryption by default (extra on this beneath). This prevents cybercriminals from studying the contents of an electronic mail whereas it’s in transit, often called a man-in-the-middle assault.
Most internet servers additionally use TLS for safe searching—you would possibly acknowledge it because the lock image on an internet browser once you’re on a safe web site. This sort of encryption replaces its predecessor, Safe Sockets Layer (SSL).
Subsequent, we’ll take a look at forms of encryption that safe knowledge on the server.
PGP
Fairly Good Privateness (PGP) was the primary profitable implementation of a public-key encryption resolution for electronic mail.
Within the easiest phrases, PGP encryption works by producing a random session key that the sender encrypts utilizing the recipient’s public key. The sender then shares the encrypted session key with the recipient, who can decrypt it with their non-public key. Lastly, the recipient makes use of this session key to decrypt the message.
PGP encryption protects knowledge because it travels and on the server. This is named data-at-rest encryption or end-to-end electronic mail encryption, and it means solely the supposed recipient can decrypt the message. Thus, it protects delicate data from cybercriminals who would possibly goal your electronic mail server.
To make use of PGP encryption, customers usually must obtain an add-on—suppliers like Outlook, Apple, and Thunderbird have PGP add-ons accessible. Nevertheless, the sender and recipient should each set up the add-ons and allow PGP encryption to ship safe messages.
S/MIME
Safe/Multipurpose Web Mail Extensions (S/MIME) is a extensively used protocol for sending encrypted messages with a digital signature. Like PGP, S/MIME offers end-to-end encryption, securing messages in transit and on the e-mail server.
This protocol additionally permits the sender to digitally signal the message, authenticating their id and the integrity of the info they ship. So it provides the recipient peace of thoughts that the message comes from a official sender and nobody intercepted or altered the content material alongside the way in which.
S/MIME additionally makes use of uneven encryption, requiring public keys from a certificates authority. This implies the sender makes use of the recipient’s public key to encrypt the message, then the recipient decrypts it with their non-public key. Moreover, the sender makes use of their non-public key to digitally signal the message.
Most main electronic mail suppliers—together with Microsoft (Alternate and Outlook), Google, and Apple—help S/MIME encryption by means of plugins. Nevertheless, each the sender and the recipient must allow S/MIME encryption to ship safe messages. Moreover, directors can arrange S/MIME encryption for all the e-mail customers of their group.
Net portal
Net portals are a safe different to make use of when it’s essential share extremely delicate knowledge, akin to protected well being data or monetary data, because it’s greatest to not ship that data over electronic mail. Not solely is it not well worth the threat of compromising the recipient’s knowledge, however rules just like the Well being Insurance coverage Portability and Accountability Act (HIPAA) usually prohibit it.
With this methodology, the sender notifies the recipient by way of electronic mail that they’ve a brand new encrypted message. The recipient should then log into the safe portal to retrieve the message. This fashion, you may nonetheless benefit from the comfort of speaking over electronic mail whereas defending the recipient’s knowledge and complying with rules like HIPAA.
Safe emails in transit with Twilio SendGrid
Need to know the way Twilio SendGrid secures your messages? By default, SendGrid makes use of opportunistic TLS encryption for outbound emails. This implies we try and ship electronic mail over a TLS-encrypted connection so long as the recipient’s server accepts an inbound TLSv1.1 or increased connection. Nevertheless, if the recipient’s server doesn’t help TLS, we ship the message unencrypted.
You can too go for the enforced TLS setting, which lets you specify the recipient has to help TLS. Nevertheless, for those who select to implement TLS and the recipient’s inbox supplier doesn’t settle for the TLS encryption, we received’t ship the message. You’d see this as a block occasion with the outline “TLS required however not supported.”
Now that you’ve got a greater understanding of electronic mail encryption, be taught extra concerning the different electronic mail safety elements that influence sender repute and deliverability in our 2022 E-mail Deliverability Information.
Or for those who’re prepared to start out sending safe emails with SendGrid, join free right this moment.
