Zero Trust Explained
Updated on 12 February 2026
Traditional security concepts are based on the assumption that there is a clearly defined, trusted internal network. However, this is no longer realistic in many organisations: Applications are being migrated to the cloud, employees access specialist systems on the move, and external service providers are involved. In this environment, the traditional network perimeter loses its protective effect. And it’s these new circumstances that Zero Trust addresses.
Zero Trust Definition
Zero Trust describes a security approach that assumes that neither users nor devices or services are inherently trustworthy, regardless of whether they are inside or outside your own network. Every access request is individually checked, approved and continuously monitored.
The focus is no longer on the network as a trust zone, but on identity, context and the specific access scenario. Zero Trust is implemented in different ways depending on the organisation, the technical starting point and regulatory requirements.
The core idea is: Trust is not assumed; instead, it is granted situationally and according to clearly defined rules, and can be withdrawn at any time if conditions change.
Zero Trust Principle
Zero Trust combines several core principles which together form a resilient security architecture:
- Least-privilege access: Each permission is defined as narrowly as possible and granted only for the specific resources required.
- Strict identity verification: Every access attempt requires strong, unambiguous authentication, regardless of whether it originates from the internal network, the cloud or an external source.
- Context-sensitive security model: Access decisions take additional factors into account, such as device status, network origin and user behaviour.
- Fine-grained segmentation: Systems and services are isolated from each other to prevent the lateral spread of attacks.
- Continuous monitoring: Activities are continuously analysed in order to detect suspicious behavioural patterns at an early stage.
The result is a security model that is significantly more dynamic and robust than earlier perimeter-based approaches.
Zero Trust Access for Comprehensive Network Security
Zero Trust changes the way access is managed in networks. Instead of broad network access permissions, controlled and precisely defined connections are created:
- Secure remote and cloud access: Employees can only access the applications they actually need, regardless of location.
- Fine-grained access control: Service providers are only granted access to the machines or applications they need for their task.
- Limiting security incidents: If an account is compromised, the impact remains limited to the smallest authorised segment.
- Reduced attack surface: Clear-cut micro-perimeters significantly reduce the number of systems that can be reached.
Zero Trust therefore establishes a security culture in which access is not generalised, but is controlled individually and based on risk.
Zero Trust as Part of Cyber Security Concepts
Zero Trust is not an isolated security principle, but an additional layer of security within modern cyber security concepts. In other words, Zero Trust is not something that can be bought; it is an architectural and organisational principle.
In holistic security architectures, Zero Trust complements traditional measures such as firewalls, endpoint security or intrusion detection systems by focusing on identities, context and continuous verification.
While traditional security measures primarily protect access to the network, Zero Trust focuses on access to specific applications, data and services. This also applies within networks that are already protected.
For public authorities and companies, this means a significant increase in resilience: Even if attackers overcome certain lines of defence, Zero Trust mechanisms prevent them from spreading unnoticed through the network or accessing particularly sensitive systems. This makes Zero Trust a key component of a multi-layered, future-proof security strategy that can flexibly adapt to new threat scenarios.
Examples of Zero Trust Architecture Use Cases
Zero Trust can be implemented in different sectors and organisational contexts. The following examples show typical fields of application and scenarios.
Telematics Infrastructure 2.0
The further development of the telematics infrastructure follows a principle that is closely aligned with Zero Trust: Access to medical data and applications may take place only after unambiguous identity verification and within clearly defined roles. The protection of sensitive information is ensured not by network boundaries, but by strict, object-based access rules.
Industrial Environments
In industrial production networks, IT security meets complex OT infrastructures. Here, Zero Trust enables:
- precisely controlled remote maintenance access,
- strict separation of production lines and control systems,
- protection against unnoticed lateral movement across machine or plant networks,
- reduction of the attack surface in environments where many devices and protocols remain in use long-term.
This approach is particularly relevant for critical infrastructure operators and companies with distributed production sites.
How to Implement Zero Trust Concepts
The transition to a Zero Trust architecture is gradual and requires both organisational and technical adjustments.
Recommended steps:
Implementation is an ongoing modernisation process that is guided by real usage scenarios, regulatory requirements and evolving threat landscapes.
Zero Trust without a VPN – but with genua
Modern Zero Trust approaches are increasingly replacing traditional VPN models. genua, as part of the Bundesdruckerei Group, provides solutions that no longer grant access at network level, but exclusively at application level.
The advantages of this approach are:
- Selective access: Users can see and reach only the applications they have been authorised to access.
- Hidden backend: Systems remain protected against direct external access, as there is no longer any network exposure.
- Adaptive policies: Access is based on identity, device status and other contextual information.
- Reduced complexity: No static tunnels and no full network exposure; lower risk and simpler administration.
This creates a modern remote-access structure that is specifically suited to hybrid working models and mixed IT/OT environments.
Overview of the Bundesdruckerei Group’s Zero Trust Solutions
The Bundesdruckerei Group’s solutions are building blocks for Zero Trust models; their effectiveness depends heavily on how consistently the principle is implemented within the organisation.
The Bundesdruckerei Group offers a very broad range of components that are ideally suited to supporting a Zero Trust architecture – from identity management and certificates, to network and infrastructure security, through to data exchange solutions that comply with data protection and compliance requirements.
For organisations with high security requirements, sensitive data or complex structures, a Zero Trust implementation based on these solutions can be a sensible and sustainable approach.
As part of the Bundesdruckerei Group, genua GmbH offers various solutions that address key elements of a Zero Trust model:
- genusphere: Access to applications without a VPN, including role-based rules, identity verification and context-sensitive security decisions.
- genubox: A solution for secure remote access in industrial environments that strictly limits access and logs activity in an audit-compliant manner.
Both products support public authorities and companies in introducing zero trust gradually and without extensive network reconstruction.
The Bundesdruckerei GmbH offers Bdrive as a secure platform for exchanging and collaborating on sensitive data.
D-Trust is the provider within the Bundesdruckerei Group for digital certificates, electronic signatures for public authorities and companies, personal and organisational certificates as well as TLS/SSL certificates and certificates for devices and machines.
The Bundesdruckerei Group’s approach is designed to ensure that security, authenticity and data exchange in compliance with data protection requirements are guaranteed even for mobile endpoints, external access or cloud-based services. This is typical of Zero Trust scenarios in which traditional trust boundaries (e.g. the internal network) no longer apply.
