Air Gap: Communication in an Isolated System
If you’ve seen “Mission Impossible,” you probably remember the iconic vault scene in which Tom Cruise is hanging upside down from the ceiling trying to access secret data. The stunt is nerve-wracking, but he had no other way to access the data: the computer could not simply have been hacked because it was not connected to a network – it was “air-gapped.”
Even almost thirty years after the movie was released, the air-gap concept is still an important security measure in companies. It is particularly relevant for industries that work with highly sensitive or classified information, such as authorities and government organizations, companies in the financial and healthcare sectors, and critical infrastructures.
What is an “air gap”?
The term “air gap” describes a system that is physically and logically isolated, i.e., has no direct connection to the Internet or other networks. Information can only be exchanged between the systems via mobile storage devices. This separation serves to protect against cyberattacks, data leaks, and unwanted access.
Air gaps not only offer the greatest possible confidentiality and protection against unauthorized access but can also contribute to cyber resilience, for example by strictly separating the communication channel from external connections. In other words, the internal communication channel runs on a separate infrastructure (e.g., a dedicated server) and can continue to be used even in the event of an Internet outage, especially for crisis communication. This allows companies to ensure business continuity even if their regular (and interconnected) systems are no longer available.
Threema OnPrem, the self-hosted version of Threema Work, provides companies with a communication solution that is ideally suited for such scenarios: The messenger runs on a company’s own IT infrastructure and can be configured so that no connection to the public Internet is required. All messages are sent and received exclusively via the company’s own network. As the infrastructure is operated locally, internal communication remains functional even in the event of external IT failures or cyberattacks.
As long as no one gets physical access to the isolated system (like Tom Cruise in the vault scene), there is no way to access the company data from the outside. The air gap therefore represents an additional layer of security against cyber threats: any communication exchanged via Threema OnPrem remains in the internal system and cannot be tapped by anyone outside of it.
