Zero Trust Email

July 20th, 2021

Our third article on Zero Trust Architecture covers zero trust email and the systems it requires. In May, the Biden Administration announced a new approach to cybersecurity that included a push toward Zero Trust Architecture. We have already covered Zero Trust Architecture as a whole, and also talked about how dedicated servers are important parts of the zero trust model. Now, it’s time to talk about zero trust email.

zero trust email

Zero Trust Email and Encryption

As we discussed in our previous articles, Zero Trust Architecture begins with the presumption that an organization’s network may not be secure. Because attackers may already be inside the network, NIST stipulates that:

“…communication should be done in the most secure manner available… This entails actions such as authenticating all connections and encrypting all traffic.”

This means that emails always need encryption. While many organizations recognize external threats and encrypt their sensitive external communications, it’s still common for workplaces to use unencrypted communication methods within the company network. This is generally done under the outdated assumption that the internal network is secure.

Zero Trust Architecture understands that any attacker within the network could easily read these communications. This is why zero trust email needs to be encrypted, even when it’s within an organization’s private network. One step in this direction is to force TLS for email encryption for all entities.

The zero trust model also requires encryption at rest, so emails also need to be protected in storage, not just in transmission.

Authentication and Zero Trust Email

NIST’s publication on Zero Trust Architecture also stipulates that:

“Access to individual enterprise resources is granted on a per-session basis. Trust in the requester is evaluated before the access is granted. Access should also be granted with the least privileges needed to complete the task.”

When it comes to zero trust email, this means that sensitive messages require authentication and authorization to be read. TLS encryption alone is not sufficient, because it doesn’t have the full capability for this type of verification. While it does allow authentication and authorization on the recipient’s email account, it cannot do so on the raw message data.

LuxSci supports:

  • Sender Policy Framework (SPF) – This is a system for email authentication that can detect forged sender addresses. Due to its limitations, it is best to complement it with other email authentication measures.
  • DomainKeys Identified Mail (DKIM) – This authentication method can detect email spam and phishing by looking for forged sender addresses.
  • Domain-based Message Authentication Reporting and Conformance (DMARC) – This email authentication protocol complements SPF, allowing it to detect email spoofing. It helps to protect organizations from phishing, business email compromise attacks, and other threats that are initiated via email.

Each of these email authentication measures are useful for verifying sender identities. LuxSci also offers premium email filtering, and together these techniques limit the trust that is applied to inbound messages.

Together, these techniques identify legitimate email messages while filtering out those that are unwanted or malicious. While it isn’t directly stated in the NIST guidelines, SPF, DKIM and DMARC can all be integral parts of the zero trust framework.

Access Control and Zero Trust Email

In addition to measures for encrypting messages and verifying inbound emails, zero trust email requires granular access controls to keep out intruders. LuxSci’s Secure Email Services include a wide range of access controls that limit unauthorized access while still making the necessary resources available. These include:

  • Two-factor authentication
  • Application-specific passwords
  • Time-based logins
  • IP-based access controls
  • APIs that can be restricted to the minimum needed functionality

These configuration options help reduce the likelihood that a malicious actor can access your systems. They also limit the sensitive email data that an attacker may have access to if they do manage to compromise an organization’s network.

LuxSci’s Zero Trust Email

As a specialist provider in secure and compliant services, LuxSci’s offerings are well-positioned as zero trust email solutions. Our Secure Email aligns with Zero Trust Architecture for every industry vertical, not just HIPAA. Contact our team to find out how LuxSci can help secure your organization with a zero trust approach.

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