Zero-trust security is a framework built on a single principle: never trust, always verify. Traditional network security assumed that anything inside the corporate perimeter could be trusted. Zero-trust assumes that the perimeter is effectively gone, that users are accessing systems from a variety of locations and devices, and that every access request needs to be verified regardless of where it originates.
For most enterprise systems, applying zero-trust principles is a reasonably well-understood exercise: implement multi-factor authentication, apply least-privilege access controls, encrypt data in transit and at rest, log all activity, and verify the identity and authorization of every user before granting access.
Fax sits in an interesting position relative to zero-trust frameworks because it is a transmission channel that predates the zero-trust concept by decades and that, in its legacy form, was not designed with zero-trust principles in mind. Understanding where modern enterprise fax fits within a zero-trust framework, and what it requires from the platform to fit there, is relevant for any organization that has adopted or is adopting zero-trust as a security architecture.
Where Fax Creates Zero-Trust Considerations
Zero-trust is concerned primarily with three things: verifying identity before granting access, encrypting data in transit and at rest, and logging all activity for audit and investigation purposes. Fax touches all three.
Identity verification in fax is a less direct concept than in application access control. A fax number is not an identity credential the way a username and password is. But access to the fax platform, meaning the ability to send faxes, view inbound fax queues, and access transmission logs, is a system access that zero-trust principles apply to directly. In Passport, that access is controlled through user authentication and role-based access configuration. Staff members have access to the queues and capabilities relevant to their role, not to the entire fax environment.
The principle of least privilege, central to zero-trust, maps to Passport’s workgroup structure. A medical assistant who receives referrals in one department’s queue does not have access to the billing team’s authorization correspondence queue or to the administrator’s system-wide monitoring view. Each user sees what their role requires and not more.
Encryption in Transit: The Core Requirement
Zero-trust’s encryption requirement for data in transit is the clearest intersection between the framework and fax. A zero-trust architecture assumes that the network cannot be trusted and that data must be encrypted regardless of whether it is traveling on a corporate network or a public connection.
For fax, this means that the transmission path needs to apply encryption regardless of whether the fax originates inside or outside the corporate network. Fax 2.0’s transmission over the etherFAX network using TLS encryption satisfies this requirement. The transmission is encrypted end-to-end at the platform level, which means the security of the data in transit does not depend on the network the sender is connecting from.
Legacy analog fax machines transmitting over PSTN lines do not satisfy the zero-trust encryption requirement because the transmission is an unencrypted analog signal. A zero-trust security architecture that includes fax needs to address that gap through platform modernization.
Audit Logging and Continuous Monitoring
Zero-trust frameworks require continuous monitoring and logging of all activity to detect anomalies and support incident investigation. For fax, this means maintaining a complete and tamper-evident log of every transmission, including who sent what to whom, when, whether delivery was confirmed, and whether any access anomalies occurred.
Passport’s Enterprise Status Manager provides the continuous monitoring layer. Every transmission, successful or failed, is logged with a timestamp, sender, recipient, and delivery status. The log is centralized, searchable, and accessible to the security and compliance teams responsible for monitoring in a zero-trust environment.
For organizations that have implemented a Security Information and Event Management (SIEM) system as part of their zero-trust architecture, the Passport audit log provides the fax activity data that can be fed into the SIEM alongside logs from other systems. Fax activity is visible in the same security monitoring context as network activity, application access, and authentication events.
Implicit Trust and the Fax Number Problem
One place where fax sits uncomfortably in a zero-trust framework is the implicit trust that sending a fax to a number implies. A user who faxes PHI to a number assumes that number belongs to the intended recipient. There is no cryptographic verification of the recipient’s identity the way there is in certificate-based secure messaging.
This is a real limitation, and a zero-trust fax program needs to address it through procedural controls rather than technical controls. Fax number verification procedures, routing rules that restrict outbound faxes to pre-verified recipient numbers for high-sensitivity workflows, and training on the minimum necessary standard for what can be included in a fax all contribute to managing this risk.
The post on what HIPAA actually requires for secure document transmission covers the verification and minimum necessary requirements that apply to fax in a compliance context, which complement the technical controls that a zero-trust framework provides.
The Practical Assessment
Modern enterprise fax platforms fit within a zero-trust security framework when they provide user authentication and least-privilege access controls, TLS-encrypted transmission over a secure network, centralized audit logging for all activity, and integration capability with the SIEM and monitoring tools that the zero-trust architecture relies on.
Legacy analog machines and unencrypted fax servers do not fit within a zero-trust framework without remediation. A zero-trust security initiative that modernizes network access, application authentication, and endpoint security but leaves fax infrastructure unchanged has a gap in its coverage that runs counter to the framework’s core principle.
Schedule a strategy call with the Lane team to discuss how Passport’s security architecture maps to your organization’s zero-trust framework.
