The fax machine is still considered a secure means of communication in many places. This is not because it is actually secure, but because hardly anyone critically questions it anymore. Its true danger lies in its cultural immunity. It whirs, it prints, it seems official, and is therefore often believed without scrutiny.
But in reality, it is an uncontrolled communication channel with a digital backbone and no contemporary security checks. The biggest vulnerability is not the code. It lies in the power of habit.
"The most dangerous device on the network isn't in the server room, but next to the coffee machine."
To show that the fundamental problem, namely the human component of security, is not limited to artificial intelligence but acts systemically and across technologies, let's consider a seemingly analog relic: the fax machine. What appears as an anachronism from bygone times is, in reality, an open and often unnoticed flank in our digital everyday life.
The deceptive security of the fax machine and its real risks can be illuminated on several levels:
The Illusion of Security
The fax owes its reputation as "secure" essentially to three outdated assumptions:
Physical Directness: The idea that the signal is transmitted, as it were, uncorrupted and directly from device to device.
Technical Simplicity: The assumption that less complex technology automatically means a smaller attack surface.
Administrative Tradition: The argument that what has proven itself over decades must still be secure today.
The Digital Reality of Fax Communication
Today's fax transmissions are far from being purely analog direct connections:
Faxes today are predominantly sent and received as Mail2Fax or Fax2Mail via digital gateways.
On their way, they pass through various providers, cloud services, and servers, often without continuous or strong encryption.
Many modern fax machines or fax servers run on Voice over IP (VoIP) protocols, such as T.38 or SIP, which have their own digital vulnerabilities.
There is generally no reliable signature verification of the sender, no secure sender verification, and often no detailed, audit-proof logging of transmission processes.
The supposedly direct and secure analog channel is, in reality, a complex digital maze. This is often unsecured, rarely supervised, and remains invisible to the end-user.
The Psychological Vulnerability
The primary danger is not the fax machine itself, but the deeply rooted belief in its reliability and officiality. It seems official. Its characteristic sound sounds real. The printed document feels valid. What clicks into place, whirs, and finally outputs a printed paper is considered true and authentic by many people.
A cleverly forged fax looks, at first glance, just like a real one. And hardly anyone asks the critical questions: Who really sent this fax? Where does this information actually come from? Is it authentic or just loud and convincingly formatted?
Case Study: Pandemic Communication via Fax
During the COVID-19 pandemic, sensitive health data and important reports between authorities, medical practices, and laboratories were sometimes still transmitted by fax. What often sounded like a provincial farce in public perception was, in truth, an expression of a structural failure in security thinking.
Decisions with the highest security requirements and serious consequences were run through a communication channel that is subject to no modern security logic and yet continued to enjoy a high degree of trust.
The Apt Parallel: The Coffee Machine
The fax machine today stands in many offices like the familiar coffee machine in the hallway. It's always there, never seems suspicious, and enjoys complete trust. We press the start button. It hums and rattles. A piece of paper comes out. No one critically examines the process. No one fundamentally doubts the authenticity of the result.
Just as no one regularly checks the water filter or the internal cleanliness of the communal coffee machine, hardly anyone systematically checks whether an incoming fax actually contains the truth or comes from a legitimate sender.
IT security often focuses on complex firewalls, defending against software exploits, and managing digital certificates. In doing so, it frequently overlooks the risks lurking in the everyday and the seemingly banal.
The fax is not a gap in a specific digital protocol. It is rather a gap in our thinking and in our risk perception.
Blind trust in old, established technologies is not corrected by the technology itself. It is only broken by increased attention and critical questioning. And it is precisely this attention that is often lacking where security is most taken for granted and least scrutinized.
To close the "analog gap" and minimize the risks of fax communication, consistent measures are required:
1. Treat Fax Systems as Full-Fledged IT Infrastructure:
Fax machines and their associated digital gateways must be subject to the same stringent security requirements as, for example, email systems. This includes mechanisms for authenticating senders and receivers, complete logging of all processes, and standard encryption of transmission paths.2. Digitally Sign and Consistently Verify Faxes:
The introduction and mandatory use of digital signatures for fax communication are needed, especially in communications with authorities, in healthcare, and in other security-critical areas. A fax without a verified sender must not claim automatic validity.3. Introduction of an Audit Requirement for Security-Relevant Fax Communication:
There must be a mandatory and traceable documentation of all security-relevant incoming and outgoing faxes. This documentation must include the origin, destination address, timestamp, and responsible processors. The implicit validity of a document solely through the characteristic sound of the fax machine must end.4. Implementation of Training for Critical Trust Defense:
Targeted user sensitization is needed for the risks posed by seemingly familiar devices like the fax. Faxes are not per se evidence, but initially unverified information. Such training does not replace technical security measures but is a necessary component to break entrenched daily habits and deceptive certainties. Even if the effect of such training may be limited, it is a realistically implementable and important contribution to increasing overall security.
We build complex cyber defense systems at the level of bits and bytes and then potentially lose the battle against a device whose technology dates back to the 1980s. This happens not because the fax machine is smarter, but because in our modern, digitized world, we often no longer take it seriously enough and underestimate its risks.
The fax is not a harmless anachronism. It is a Trojan horse with a familiar operating sound.
Uploaded on 29. May. 2025