Overview 

In an era of a rapidly expanding digital landscape and day-to-day advancing cyber threats, traditional security models are struggling to keep pace. As a response to this evolving threat landscape, the Zero Trust Network Architecture has emerged as a compelling approach to protecting critical resources and data. This article explores the principles behind the Zero Trust model and discusses its advantages and disadvantages for organizations that seek to adopt this paradigm shift in cybersecurity.

What is Zero Trust?

“Zero Trust” is a cyber-security model first introduced by Jon Kindervag of Forrester in 2010. This model required the network to “never trust, always verify”. [1]  Zero Trust requires all users and devices to authenticate themselves and receive authorization before they can access any services or data. It's similar to the network having a series of security checkpoints where you must present your ID and request authorization at each one.

What is Zero Trust Network Architecture (ZTNA)?

Zero Trust Network Architecture (ZTNA) is an IT network that utilizes zero trust security principles. ZTNA focuses on providing strict access controls and verifying every device and user trying to access a network or a system. Users and devices that want to access resources of a network should pass strict authentication and authorization processes whether inside or outside the network.

When it comes to traditional network security approaches, a perimeter-based strategy is frequently used. For instance, the majority of organizations have trust in their internal network; i.e., employees, internal system devices, etc. And a user within this internal network will mostly have outright access to all of the data and internal system devices. However, over the past ten years, hackers have proved that these perimeter-based measures and tools cannot keep corporate resources secure. [2]

Zero Trust Networking, on the other hand, takes a more granular and cautious approach to security. The zero-trust framework can be broken down into seven core pillars; [3]

1. Identity and Access Management (IAM): IAM is the foundation of zero-trust and plays a crucial role in implementing a zero-trust network architecture. It involves verifying the identity of users and devices attempting to access the network resources. IAM provides identity verification, generally implemented through authentication methods such as multi-factor authentication (MFA), biometrics, single sign-on (SSO), and client certificates. By ensuring that only authorized users and devices are granted access, IAM reduces the risk of unauthorized access and potential data breaches within ZTN.

2. Device Security: This pillar focuses on ensuring the security of devices attempting to access the network. Before access is given to any device within the network, devices must adhere to certain security requirements and comply with the organization’s policies. These policies will probably include prerequisites to safeguard the network and endpoint devices. This can include ensuring that the device must run on the most stable and up-to-date security software/patches and is not infected with malware or jailbroken.

3. Network Segmentation: In Zero Trust, the network is split into more manageable, isolated chunks to prevent lateral attacker movement. In this manner, the network as a whole is safeguarded; even if one part is compromised, the rest of the network remains protected. Access between segments is tightly controlled and granted based on the principle of least privilege.

4. Application Security: Applications are essential components of the network, and their security is crucial. ZTNA ensures that applications are designed securely, with the principle of least privilege in mind, granting access only to the necessary functions for each user or device.

5. Data Security: Protecting data is paramount in Zero Trust. Data should be properly encrypted when it’s shared or stored within a computer. Further, access to these data should be appropriately monitored and controlled by the organization. Granular data access controls are implemented, ensuring that only authorized users can access specific data sets.

6. Visibility and Analytics: Zero Trust emphasizes continuous monitoring and analysis of network activities. They help ensure that the principles of zero trust are consistently enforced, providing real-time visibility into user behavior within the network, device health, and network access patterns. By collecting and analyzing these data, the network security teams can immediately spot potential risks and ominous behavior. Further, machine learning and artificial intelligence techniques can be used to enhance threat detection. This level of scrutiny ensures that access controls remain effective, privileged access is continuously validated, and any potential security issues are addressed promptly to minimize the risk of data breaches and unauthorized access.

7. Automation and Orchestration: Automation plays a crucial role in Zero Trust Network Architecture. By automating routine security tasks, the system can respond more effectively and efficiently to security incidents and policy changes. This reduces human error and speeds up incident response times.

What are the Advantages of Zero Trust Architecture?

As cyber threats develop and conventional security methods are shown to be ineffective, Zero Trust networks have become a powerful tool for protecting sensitive data and important assets. Zero Trust networks demand continuous authentication, monitoring, and authorization for every person, device, and application attempting to access resources rather than the conventional perimeter-based security strategy. The pre-eminent advantages of zero trust networks and how they improve an organization's overall security posture are as follows;

1. Enhanced Security through Micro-Segmentation

Zero trust operates under the premise that no entity, internal or external, can be trusted by default. Moreover, ZTN is often designed by micro-segmenting the traditional network, resulting in the network being divided into smaller, isolated segments, and every user is authenticated before providing access to the network segment. Therefore, the attack surface is significantly reduced, and the possible impact of security breaches is minimized with this "never trust, always verify" philosophy. It makes it more difficult for attackers to get unauthorized access by ensuring that each request is continually validated. [4]

2. Protection Against insider threats

The dangers caused by insider threats, such as malevolent employees or compromised accounts, are reduced with Zero Trust. Zero Trust reduces the potential harm that insiders can do by constantly confirming user identities and imposing the least privileged access. This strategy ensures that security measures are applied consistently to all users and devices because it is predicated on the idea that even insiders cannot be totally trusted. [5]

3. Granular Access controls

Zero Trust imposes granular access limits based on various factors, including user identification, device health, location, and behavior. Users only have access to the particular resources they require to complete their activities because access is offered in accordance with the concept of least privilege. In addition to lowering the attack surface, this minimizes the possibility of unauthorized entry. [6]

4. Adaptive Authentication and Strong Policies for access

Multi-factor authentication (MFA) and risk-based authentication are adaptive authentication methods that Zero Trust supports. Users may be asked for additional authentication factors based on contextual data, such as their location, device, or recent behavior. This enhances security while enhancing the user experience for authorized users. Also, by implementing strong policies within the organizations’ network architecture, we can ensure minimal compromise and only grant the required access to a user. [7]

5. Improved visibility and monitoring 

Organizations can view user and device behavior in real time because of the widespread logging and monitoring capabilities frequently incorporated into zero-trust networks. With this improved visibility, security issues, unusual behavior, and possible threats can be quickly identified and contained.  

What are the Disadvantages of Zero Trust Network Architecture?

Zero Trust networks offer a robust approach to cybersecurity by eliminating the concept of implicit trust and continuously verifying users and devices. However, the zero-trust approach has several disadvantages. In this article, we'll examine some of the key problems of implementing Zero Trust Network Architecture and how to mitigate them. 

1. Complexity and Implementation Challenges:

Implementing the Zero Trust Network (ZTN) model presents a multifaceted challenge, particularly for organizations with large and diverse IT infrastructures. Migrating from conventional security models to ZTN entails substantial changes in network architecture, access control mechanisms, and security policies. This complexity can result in prolonged deployment periods, escalated costs, and potential compatibility issues with existing legacy systems. [8]

Mitigation Strategy: To tackle the intricacies of implementation, organizations must adopt a systematic approach. This begins with conducting a meticulous assessment of their network and security requirements before diving into full-scale deployment. Effective planning and coordination between IT and security teams are paramount to address potential roadblocks. To ease the transition, organizations can initially pilot ZTN in smaller segments of the network to gauge its efficacy before embarking on a complete rollout.

2. Increased Management Overhead:

The core principle of ZTN revolves around continuous monitoring and verification to ensure network security. However, these constant authentication and access checks can place additional strain on IT and security teams. [8] Frequent prompts for authentication and access verification may lead to heightened processing demands and network latency, potentially impeding the user experience. 

Mitigation Strategy: To mitigate the increased management overhead, organizations should invest in efficient and scalable authentication and authorization systems. Embracing automation and deploying advanced monitoring tools can streamline the process, making it more manageable for IT personnel. By reducing manual intervention, IT teams can focus on strategic initiatives and overall network optimization.

3. Increased Security Investment:

Transitioning to the Zero Trust Network model necessitates significant investments in advanced security technologies. This includes intrusion detection/prevention systems (IDS/IPS), multi-factor authentication (MFA) solutions, encryption tools, and continuous monitoring platforms. [9]

Mitigation Strategy: To optimize security investments, organizations must conduct a meticulous evaluation of their specific security needs and risk profiles. A thorough cost-benefit analysis should inform the selection of solutions that align with the organization's budget and overall requirements. Exploring cloud-based security options and managed security services can offer cost-effective alternatives without compromising on the robustness of the security framework.

4. User and Device Onboarding Complexity:

Onboarding new users or devices to the Zero Trust Network necessitates meticulous adherence to proper authentication and access procedures. This process can prove time-consuming, especially in organizations with high employee turnover rates or frequent device updates. [9]

Mitigation Strategy: To streamline user and device onboarding, organizations must develop well-documented onboarding processes and provide comprehensive user training. Leveraging automated onboarding tools and self-service mechanisms can expedite the process, lessening the administrative burden on IT staff.

5. Potential False Positives:

Continuous monitoring and anomaly detection in the Zero Trust Network model may occasionally yield false positive alerts, where legitimate user behaviors are mistakenly flagged as suspicious activities. This can trigger unnecessary investigations and drain valuable time and resources of security teams. [8]

Mitigation Strategy: To reduce false positives, organizations should fine-tune their monitoring systems. Leveraging machine learning algorithms and context-aware anomaly detection can enhance the accuracy of threat detection, ensuring that security teams focus their efforts on genuine threats.

6. Resistance to Change and Training Needs:

Implementing the Zero Trust Network model requires a cultural shift within the organization. Resistance to change from employees and stakeholders accustomed to conventional security models might impede the successful adoption of ZTN. Proper training and education efforts are crucial to ensure smooth adoption and secure buy-in from all parties involved. [8]

Mitigation Strategy: Executives and leaders must communicate the advantages of ZTN to employees, emphasizing its role in enhancing security and protecting sensitive data. Conducting targeted training sessions and awareness programs can help employees comprehend the significance of ZTN and embrace the new security paradigm, fostering a smooth transition.

In conclusion, organizations must carefully consider facts such as complexity and implementation challenges, as well as management overheads, impacts with user experience, dependencies on IAM, and increased costs of implementing Zero Trust. Despite these drawbacks, an organization can overcome the above-mentioned challenges by carefully planning the implementation, adopting best practices, and selecting suitable security solutions. By doing so, they can fully embrace the security benefits of ZTNA and proactively safeguard their critical data and assets in today's dynamic and evolving threat landscape.

References

[1]	B. D. Gilman E, Zero Trust Networks, O’Reilly, 2017.
[2]	M. A. a. I. M. Abbadi, "Integrating Trusted Computing Mechanisms with Trust Models to Achieve Zero Trust Principles," 2022 9th International Conference on Internet of Things: Systems, Management and Security (IOTSMS), pp. 1-6, Milan, Italy, 2022.
[3]	Humanize, "7-pillars-of-zero-trust-architecture," Humanize, 09 Jan 2023. [Online]. Available: https://www.humanize.security/blog/cyber-awareness/7-pillars-of-zero-trust-architecture.
[4]	C. O. A. S. F. V. T. E. Christoph Buck, "Never trust, always verify: A multivocal literature review on current knowledge and research gaps of zero-trust," Computers & Security, vol. 110, no. ISSN 0167-4048, 2021.
[5]	O. B. S. M. S. C. Scott Rose, "Zero Trust Architecture," National Institute of Standards and Technology (NIST), August 2020.
[6]	C. C. Steve Turner, "the-zero-trust-extended-ztx-ecosystem," Forrester, 23 August 2021. [Online]. Available: https://www.forrester.com/report/the-zero-trust-extended-ztx-ecosystem/RES137210?ref_search=0_1689863928529.
[7]	Gartner, "Market Guide for Zero Trust Network Access," Gartner Research, 29 April 2019. [Online]. Available: https://www.gartner.com/en/documents/3912802.
[8]	C. Ayuya, "What Are the Benefits and Disadvantages of Zero Trust Security?," enterprisenetworkingplanet, 23 June 2023. [Online]. Available: https://www.enterprisenetworkingplanet.com/security/prosa-and-cons-of-zero-trust-security/#Disadvantages_of_zero_trust.
[9]	J. Flanigan, "Zero Trust Network Model," 2018.

Author Details

Chirath De Alwis is an information security professional with more than 9 years of experience in the Information Security domain. He is armed with MSc in IT (specialized in Cybersecurity) (distinction), PgDip in IT (specialized in Cybersecurity), BEng (Hons) Computer networks & Security (first class), AWS-SAA, SC-200, AZ-104, AZ-900, SC-300, SC-900, RCCE, C|EH, C|HFI and Qualys Certified Security Specialist certifications. Currently involved in vulnerability management, incident handling, cyber threat intelligence, and digital forensics activities in Sri Lankan cyberspace. 

Contact: [email protected]

Umeshika De Seram is a final year undergraduate student with BSc in Hons Management Information Systems at the University College of Dublin, Ireland. She’s currently a Cyber Security Trainee at AION. She has certification on NSE 1 Network Security Associate

Contact: [email protected]

Jethendri Wathsala Perera is a first-class graduate with a Bachelor of Information Technology (Major in Web and Mobile Application Development and Minor in ICT Management) from Victoria University - Australia. She’s currently a Cyber Security Trainee at AION. She has certification on NSE 1 Network Security Associate and Qualys Vulnerability Management Foundation.  

Contact: [email protected]

H.M.H Sanjeewa is an undergraduate student pursuing a BSc Hons in Computer Science with a specialization in Network & Network Security at Kingston University, UK. Additionally, he holds a Pearson HND in Computing (specializing in network engineering). Currently, he is gaining valuable experience as a Cyber Security Trainee at AION Cybersecurity. Sanjeewa has successfully completed the NSE1 Network Security Associate certification.

Contact: - [email protected]

Vidusha Shalani is an undergraduate student in BSc Cyber Security and studying in their second year at the Australian College of Business and Technology. She is a Cyber Security intern at AION. She completed the certificates in NSE 1 and Ethical hacking for beginners.

 Contact: - [email protected]