Zero Trust – The Essential Guide

Or what we know so far about zero trust

The rising interconnection of IT and OT infrastructure within the organizational framework, and the growing need to balance users’ requirements to access data from anywhere at any time from any device to support the organization’s mission have given rise to the basis of the zero trust approach. The model emphasizes the need for thorough authentication and authorization for all access requests, regardless of whether they are internal or external.

Zero trust helps to prevent breaches by minimizing the attack surface and better protecting sensitive data. However, the implementation of a zero trust security model is crucial in preventing breaches and protecting sensitive data. By reducing the attack surface and enforcing strict authentication and authorization policies, zero trust can help organizations limit the scope for attackers to compromise their systems and data. As such, zero trust is an invaluable security concept for any organization striving to properly protect its systems and data.

The zero trust approach works on finding a workable middle ground that follows the basic principle of ‘never trust, always verify,’ a guiding fundamental assumption that has been in place since 2010 when John Kindervag, then at Forrester Research, coined the term. Trust should never be automatically granted to either user accounts or assets solely based on their location within a network or ownership of the asset. In order to grant access to an enterprise resource, verifying the identity of both the subject and device is a twofold process that needs to be completed before starting a session.

The zero trust approach is an ever-evolving strategy for dealing with cyber security issues. Instead of just relying on a networked perimeter, it takes into account users, devices, and resources to create a dynamic defense system. The goal of the model is to reduce the risks posed by a standard, perimeter-focused security system. This approach is based on the idea that ‘there is no single dependable source’, and hence seeks to create a safer work environment. The perspective implies that malicious actors may be both inside and outside the network, so it is important to take precautionary measures with all network traffic. Subsequently, it is imperative to check that no interaction takes place until both parties have been adequately authenticated and authorized on each occasion.

Incorporating zero trust in OT (operational technology) environments is exceptionally challenging given the criticality of the function performed by these systems in terms of operational safety and reliability and the underlying characteristics and limitations of the OT assets. Critical infrastructure asset owners and operators largely depend on OT assets to monitor and control industrial processes, with many of these industrial control systems (ICS) lying on-premises, and more often than not, nowadays connecting to IT systems that are likely to be off-premise or cloud-based.

What is the concept all about?

The Zero Trust approach is based on the idea that no one should be trusted within a network, regardless of their affiliation or position. The security model steps away from traditional approaches which assume all users, resources, and systems within the network are trustworthy.

Under the Zero Trust concept, all users are authenticated and their activity is monitored in real-time for any suspicious behavior. This is an effective way of reducing the risk of malicious activity within a network as it requires multiple layers of security and verifiable trust before access is granted to sensitive resources. The Zero Trust concept provides an added level of safety and security to networks and it is an approach being adopted by many organizations worldwide.

The core principle of the zero trust approach is that all users, devices, and networks must be verified and authenticated before being granted access to the system. The concept has been gaining significant traction from government and industry circles in recent years. The idea behind the concept is to ensure that no user, device, or network should be trusted by default and must be subject to stringent access control measures. This means that all users and devices are treated as if they are untrusted and must demonstrate their identity before accessing any system or network.

By applying a zero trust approach, organizations can enhance the security of their systems and networks while enabling real-time access control decisions. Using strong security measures such as multi-factor authentication, organizations can reduce the risk of unauthorized access and protect their data from malicious actors. Similarly, with the implementation of the zero trust concept, organizations can ensure that only those with legitimate authorization can access their data. Through robust security measures such as multi-factor authentication, businesses can actively reduce their risk of unauthorized access and protect against malicious actors. By embracing this zero trust concept, organizations can build a stronger foundation for secure data access and protect their assets from harm.

Why is it called zero trust?

Zero trust approach is based on a security model that requires all users and devices to be authenticated and authorized before they can access any data or application. It is essential to be cautious when allowing any user or device access to your network, as it cannot be assumed that they are trustworthy, regardless of their external or internal status. By requiring all users and devices to be authenticated and authorized, organizations can ensure that only authorized users and devices have access to data and applications. This helps to protect data and applications from being accessed by unauthorized users, which can help to prevent data breaches and other security incidents.

By requiring all users, devices, and applications to be authenticated and authorized, organizations can ensure that only authorized users and devices have access to data and applications. This helps to protect data and applications from being accessed by unauthorized users, which can help to prevent data breaches and other security incidents.

The term ‘zero trust’ comes from the fact that in this security model, organizations do not automatically trust any user or device, regardless of whether they are inside or outside the network. All users and devices must be authenticated and authorized to access data or applications. The fundamental principle is that it is better to be safe than sorry.

For every access request, the approach works on explicitly verifying the context available at access time, taking into account static user profile information or non-person entity information and dynamic information such as geolocation, the requesting device’s health and credentials, the sensitivity of the resource, access pattern anomalies, and whether the request is warranted and following the organization’s business process logic.

In the event of meeting criteria set out by the organization’s defined policy, a secure session is established that secures information both transferred to and from the resource. The zero trust approach extends its tentacles to create a real-time, risk-based assessment of resource access and access pattern anomaly detection with continuous policy evaluation are performed. This behavior is used to establish and maintain access. The structure can also protect organizations from non-organizational resources that their users and applications may connect to, helping to stop threats originating from outside of the organization’s control.

The zero trust approach also presumes that a breach is either likely to occur or has already taken place; hence, it restricts access only to the required elements and continuously searches for suspicious or malevolent behavior.

Architecture and purpose

Zero trust architecture incorporates system security automation, detailed risk-based access controls, and thorough security monitoring to cover the entirety of an organization’s infrastructure. This enables continuous security monitoring with a holistic approach, thus guarding data against any dynamic threats in real time. Data security is vital and adhering to the least-privilege access model gives you an optimum level of control. This is done by considering each access decision in terms of who, what, when, where, and how to make sure that the right people have access to the right resources at the right time.

Every zero trust approach must work on determining the credibility of devices and users while working towards protecting organizational access requests that occur both across the enterprise-owned part of the infrastructure and the public/non-enterprise-owned part. With the primary aim of ensuring that all users, devices, networks, and systems within an organization are continuously verified and authenticated and that any data or resources accessed have been appropriately verified and validated. Through this, organizations can protect themselves against different forms of cyber threats, and secure their networks and systems without any manual intervention or security resources.

For an organization to benefit from a zero trust model, it needs to secure the complete extent of its user access such as external users, internal users, privileged users, devices, networks, systems, and cloud-based applications. Organizations have typically deployed identity and access management (IAM) solutions such as multi-factor authentication, tokenization, virtual private networks (VPNs), malware and data leak detection, authentication smart cards, and single-sign-on (SSO) to carry out necessary authentication and verification.

Apart from authentication, organizations have also benefited by taking necessary steps that deliver data segmentation and encryption and developing organization-wide policies to review and enforce regular permission reviews. Additionally, the use of advanced analytics, such as machine learning and anomalous behavior detection, has been known to help to ensure that the zero trust security model is always up to date. Additionally, regularly applying operating system patches, updates, and security policies keep the organization’s structure safe and secure.

Pillars of zero trust

With the overarching role played by the zero trust structure within the organization, there exist certain pillars on which the zero trust approach is based. There are several different versions of the pillars, but the set of guiding principles that organizations can follow to implement a zero trust security model typically include:

1. Always verify: In a zero trust model, you should always verify the identity of users and devices before granting access to resources.
2. Never trust, always verify: Don’t automatically trust users or devices, even if they are inside the network perimeter. Instead, verify their identity and assess their level of risk before granting access.
3. Least privilege: Grant users and devices the minimum level of access necessary to do their job. This helps to minimize the attack surface and reduce the risk of a breach.
4. Microsegmentation: Divide the network into smaller segments, so that if one part of the network is compromised, the rest of the network is still protected.
5. Continuous monitoring: Monitor network activity continuously, so that you can quickly identify and respond to any suspicious activity.
6. Identity and access management: Implement robust identity and access management controls, including multi-factor authentication, to ensure that only authorized users and devices can access resources.

Using these pillars of zero trust helps organizations to track and build structure elements critical for building a comprehensive zero trust security architecture, which includes access control, segmentation, identity trust, observability and analytics, and constricted administration. Additionally, foundational technologies including multi-factor authentication, encryption, and SSO should be in place to achieve zero trust.

Principles of zero trust

With the zero trust approach built on the principle of ‘never trust, always verify,’ largely forming the basis for how entities are identified and verified, organizations must be prudent when verifying users and devices, typically using a combination of multi-factor authentication. Network security layers are monitored and enforced to ensure that only authorized users with the right level of access are allowed to connect to the system, while restricting or blocking any unverified traffic.

Some of the principles of the zero trust approach can be laid down as:

1. Verify Every Access Request: All access requests from users, devices, and applications should be verified every time, to ensure that the request is being granted to an authenticated user, device, or application. This can be done through multi-factor authentication (MFA) or other identity verification processes.

2. Least Privilege Access: Users should only be granted the least amount of access required to perform their job. This means that users should not be granted access to sensitive resources unless absolutely necessary. Furthermore, access to the network should be restricted to only those users, devices, and applications that have been verified and authenticated.

3. Always Monitor and Enforce Access Policies: Organizations should use technologies such as identity and access management (IAM) systems to monitor and enforce access policies. All activity on the network must be monitored and logged for auditing and security purposes. This will assist in tracking anomalous network or user activity.

4. Use Encryption and Segmentation: Organizations should use encryption and segmentation to protect their sensitive data. All data must be encrypted to ensure that it remains secure both in transit and at rest. Additionally, encryption ensures that only authorized personnel can access sensitive data, and segmentation ensures that data is securely separated from other data sets. The network should be segmented into small, isolated units to reduce the attack surface and minimize the risk of lateral movement within the network.

5. Automate Access Control Decisions: Organizations should use automation to help make access control decisions. Automation can help ensure that access policies are consistently enforced, and that access requests are handled in a timely manner.

6. Regularly Test Security Measures: Organizations should regularly test their security measures to ensure that they are working as intended. Regular testing can help identify any potential weaknesses for which remedial action can be carried out.

7. Data Collection: Companies must collect data on asset security, network traffic & access requests, process the data, and leverage any findings to strengthen policy formulation and implementation. This is an essential step for organizations to ensure complete protection of their assets. These insights can also be used to provide context for access requests to the network.

Using zero trust to secure OT environments

OT environments include those processes and technologies that control and monitor industrial infrastructure and manufacturing equipment. These frameworks consist of digital devices that interact with physical objects that keep factories, manufacturing equipment, water supplied, power facilities, and such critical services operational. These services are nowadays using a blend of IT and OT assets.

Many ICS organizations maintain the use of older equipment as it is usually preferable for safety, reliability, and cost-effectiveness. Additionally, due to ever-evolving technology, many vendors are now providing devices with varying functionalities. Furthermore, the nature of critical infrastructure organizations often prioritizes availability and safety over other requirements, such as confidentiality. This approach has led to several OT devices and components having a low tolerance for communication interruptions.

To secure an OT environment using the zero trust approach, organizations should implement a multi-factor authentication system that requires users to provide multiple pieces of evidence to prove their identity. Additionally, OT organizations should use network segmentation as far as possible to limit access to only those resources that are necessary for the user, device, or application to perform their job. This technique will help to reduce the attack surface and limit the damage that can be done if an adversarial attacker can gain access to the system.

The zero trust approach can be deployed across OT organizations by implementing a host of security measures, including:

1. Establishing a security perimeter: This should be set up around the OT network to prevent unauthorized access and will work as a safeguard when hackers breach the IT networks. It can be done by using firewalls, intrusion detection systems, and other security measures.
2. Implementing authentication and authorization: Focus on these two mechanisms is crucial when it comes to the adoption of zero trust in OT organizations. Both authentication and authorization must be implemented to ensure that only authorized users have access to the OT network. In the case of a user, biometric authentication can also be adopted. This can be put in place by using multi-factor authentication, role-based access control, and other such security measures.
3. Monitoring and logging: These should be deployed to detect any suspicious activity on the OT network. It can be carried out using network monitoring tools, log analysis tools, and similar techniques.
4. Implementing encryption: Encryption should be carried out to protect data when in transit and at rest. It can be done by using encryption algorithms, secure protocols, and similar security measures.
5. Implementing patch management: In the case of OT environments, executing patch management is extremely crucial, as it works on managing patches or upgrades for software applications and technologies. It also covers the acquisition, testing, and installation of multiple patches to an administered computer system to fix known vulnerabilities.

Applying zero trust in Industrial Control Systems

ICS systems are the primary control systems that power OT environments that help manage the flow of goods and materials within a factory. One of the key tasks of ICS is to ensure that all steps in the production process are secure, including the key steps such as manufacturing, delivery, and storage. These ICS systems are vulnerable to security threats because they rely on legacy systems, their connectedness to the internet, and their ability to control physical systems.

Zero trust is a key part of the successful operation of ICS, as it allows for a guarantee that all steps in the production process are secure. This is possible because ICS is designed with a secure key distribution system that ensures that no one control ever reaches the wrong person. To reduce these risks, organizations should implement a zero-trust approach to ICS security. This approach involves verifying the identity of every user, device, and network connection, as well as monitoring and logging all access to the system. Access is granted on an as-needed basis, and all traffic is encrypted.

Furthermore, organizations should also limit access to only privileged users and deploy additional defenses to protect against malware. Finally, organizations should continuously audit the system and its configurations to ensure that the security measures remain up-to-date and effective.

Additional Questions:

1.  Is zero trust a strategy?

Zero trust is an emerging cybersecurity strategy that focuses on verifying users and devices before granting access to an organization’s resources. Based on the principle of ‘never trust, always verify’ and designed to reduce the attack surface of an organization, the approach assumes that all users, devices, and applications are untrusted and must be verified before granting access.

The zero trust strategy focuses on securing access to sensitive data and applications, rather than relying on traditional perimeter-based security measures. It plays a critical role in the traditional ‘defense in depth‘ approach to security, where organizations build a secure perimeter around their networks, no longer capable of dealing with rising threats and attacks.

2.  What are the advantages of zero trust?

Zero trust provides an extra layer of security which can help protect sensitive data and prevent unauthorized access. By utilizing a zero trust framework, organizations can create a system of security controls that protect their network from malicious actors. This framework involves the use of authentication and authorization methods to ensure data is only accessed by those who have been granted access.

The zero trust approach helps protect data in transit and allows organizations to quickly detect breaches and take action against suspicious activities. By creating a secure environment that protects sensitive data, zero trust helps organizations increase the security of their networks and prevent unauthorized access.

The approach relies on continuous monitoring and verification of user access and transactions, an approach that aims to reduce the risk of cyber attacks. However, a zero trust security model also has disadvantages such as the cost involved in implementing and maintaining the system, as well as the complexities associated with larger organizations which may not be suitable for all organizations. Furthermore, providing granular user access to applications can be challenging and may require additional resources to manage.

3.  What are the disadvantages of zero trust? How to overcome them?

Zero trust approach can be complex and time-consuming to set up, while also requiring significant management. It can also be expensive to deploy, making it a less viable option for smaller businesses. Moreover, the need for multiple authentication layers and additional steps to access critical assets can lead to user frustration. Lastly, although zero trust networks provide added security, they may also limit access to important applications or services due to overly strict policies.

Another underlying limitation of the zero trust approach is that the processes and procedures can only be as secure as the authentication protocols they use, so it’s important to choose systems with strong authentication methods. These authentication mechanisms also need to be tested and chosen with utmost care to ensure that systems are completely safe.

The limitations can be overcome by partnering with a security vendor, who can help build and implement an effective solution. The ethos and behavior patterns of the organization must be tailored to adopt the new mechanism and necessary steps must be undertaken to ensure it is implemented successfully. While it can be challenging to implement and maintain at scale, adopting a zero trust approach will bring about increased security and user convenience.

4.  How is zero trust different from VPN?

The zero trust approach is focused on the authentication and authorization of users, while VPNs are used to create a secure connection between two or more networks. As such, zero trust security is more about providing secure access to a user, while VPNs are used to bridge networks. Zero trust security also takes into account the user’s device and location, as well as their identity. This is an important distinction because it means that zero trust security encompasses a wider range of authentication measures than a VPN.

Furthermore, with zero trust security, users are only granted access to the resources they need to perform their tasks with no additional privileges or access. This ensures that all users are properly authenticated and authorized, thus providing an additional layer of protection in comparison to a VPN.

Zero trust security emphasizes data encryption and segmentation of networks, while VPNs encrypt data at the application layer. VPNs are an important tool for remote access and networking, but VPNs alone don’t provide the same level of security as a zero trust approach. VPNs are unable to detect and prevent malicious activity on the network, leaving data vulnerable to potential threats.

5.  Why do we need zero trust?

Zero trust is an important concept in modern security, as it helps to protect organizations from malicious actors. Zero trust is based on the idea that no one should be trusted by default and all access should be verified and monitored. This means that organizations need to ensure that all users are authenticated and authorized before they can access sensitive data or systems. By implementing a zero trust model, organizations can ensure that their systems and data are secure and that malicious actors are unable to gain access.

The approach helps to protect organizations from malicious attacks while assuming that no user or device is to be trusted, and that all users and devices must be authenticated and verified before access is granted. This theory supposes that organizations should not have faith in any user or device, no matter if they are external or internal to the corporate network.

The implementation of a zero trust model enables organizations to reduce the attack surface of an organization by limiting access to only those who have been authenticated.

6.  Who invented zero trust?

The zero trust approach was first introduced in 2010 by John Kindervag, a security analyst at Forrester Research. In his paper, Kindervag argued that the traditional approach of trusting all internal network traffic was no longer sufficient to protect organizations from modern cyber threats. He proposed a new security model, known as zero trust, which assumes that all network traffic, both internal and external, is untrustworthy and must be verified before it is allowed to access the organization’s resources. The paper has been credited with popularizing the concept and bringing it to the forefront of security discussions.

John Evans

Customer Success Manager John has over 15 years’ experience in managing clients and helping them achieve their desired outcomes. John heads up our customer success and community management at IndustrialCyber, taking care of clients’ needs, inquiries and advertising.