Increasing networking across organizational boundaries and the integration of external services into internal processes have become an increasing challenge for a company's IT security in recent years. Remote working, cloud services, cross-organizational networking - all these developments lead to more complex, security-relevant requirements and increase the attack surface for cyber attacks. The implementation of a Zero Trust strategy is therefore becoming increasingly important in the current cyber security landscape.
The Zero Trust approach is based on the principle of minimum rights (so-called least privileges) for all users or devices at all levels of a network environment.
It is assumed that no device or user inside or outside the network is trustworthy by default. This means that only those users or devices should have access to resources that really need them. This means that authorizations must be assigned as granularly as possible by default, so that in the event of a security incident (for example, if a user opens a malicious attachment from a phishing email), uncontrolled data leakage or the manipulation of all data in a network is prevented.
The primary goal of the Zero Trust approach is to increase cyber security in the company by assuming that generally no device or user, whether internal or external to the organization, is trusted. This lack of trust in every access presupposes that every access to a system or data requires prior authentication and authorization.
Whether access is authorized is evaluated using the highest quality information possible. Log analyses on the behavior of the systems used for access, information on device monitoring or current threat information are included in the decision-making process.
The implementation of Zero Trust in the company could, for example, include the following IT security measures, adapted to the organization's processes:
A multi-factor authentication solution can be used for identity and access management, which ensures that users prove their identity to the Active Directory as the central directory service for user administration each time they attempt to log in.
Monitoring network activities in real time and monitoring the network landscape help to detect and react to unusual activities and patterns. Analyzing log files using appropriate SIEM (Security Information and Event Management) tools is essential. The collected and analyzed log data is the basic information that, together with data from other sources, provides valuable information on unusual network activities. For example, if a user attempts to log in many times in a row with the wrong access data, this can be considered unusual activity. Such login attempts can indicate a potential security problem, such as a brute force attack in which the attacker attempts to try out different passwords to gain access. With the help of appropriate log file analysis tools, the AI can use machine learning to identify anomalies in user behavior and, for example, block the corresponding user account from logging in.
The use of MDM solutions ensures that security policies are enforced by centralizing the management of mobile devices. Appropriate tools for user management or password assignment are ideal for enforcing security policies and verifying compliance with them.
In contrast to the Zero Trust approach, there is the classic perimeter-based security model. This approach assumes that everything inside the network perimeter is trustworthy. Everything outside the network is classified as dangerous. In this model, internal network users are trusted by default, for example. The main focus of access control is on securing the internal network through gateways and firewalls. Security checks are often less stringent. Modern threats (AI-driven ransomware, phishing, etc.) can thus move and spread more easily once inside the internal network.
The network must be segmented in such a way that in the event of a security incident, the attacker does not have access to the entire network, but the attack is detected and prevented using an intrusion detection and prevention system. A corresponding micro-segmentation including granular firewall configuration using VLANS must be implemented.
