The Rise of Zero Trust Architecture in Modern IT Infrastructure

Jose Jorge Santos, Director of IT Infrastructure and Operations, Salvador Caetano Group

In an era marked by increasingly sophisticated cyber threats and a growing reliance on cloud computing and remote work, traditional perimeter-based security models are proving inadequate to safeguard sensitive data and critical assets. As a result, organizations are adopting an approach based on behavioral trust.

The Concept of Zero Trust Architecture

Zero Trust Architecture (ZTA) inverts the assumption that we are familiarized with in courts of law, by assuming that everyone is bad until they prove that they are not! And we must keep proving it along the way! This is valid whether a user or device is inside or outside the corporate network perimeter. For this, ZTA promotes continuous authentication, least privilege access controls, and microsegmentation to enforce strict access controls and limit lateral movement within the network. This approach is particularly critical in today's distributed computing environments, where employees access corporate resources from a variety of devices and locations.

Key Principles of Zero Trust Architecture

1. Identity Verification: Authentication and authorization mechanisms are enforced to verify identity not only of users but also of devices and applications requesting access to resources. This act often involves multi-factor authentication (MFA), biometric authentication and identity federation to ensure that only authorized entities are allowed.

2. Least Privilege Access: In this approach, access privileges are granted on a need-to-know basis, with users and devices only given access to the specific resources required to perform their tasks. By minimizing access rights, organizations can mitigate the risk of insider threats and limit the potential damage caused by compromised accounts. Always keep in mind the user and device combination can dictate different levels of access. For instance, the user on a mobile device, may not have the same level that the same user on a computer.

3. Micro-Segmentation: While the trend is to apply it mostly on legacy and on-prem resource access needs, ZTA advocates for the segmentation of network resources into smaller, isolated segments or zones, each with its own access controls and security policies. This limits the lateral movement of threats within the network and contains breaches to specific segments, minimizing their impact. Some pieces of software, aka Zero Trust Client, may enforce it even at the client level, restricting DNS and routing rules.

4. Continuous Monitoring and Analysis: Real-time monitoring of network traffic, user behavior, and security events to detect anomalies and potential threats. Advanced analytics are possible on this collected data to leverage the behavioral analysis. AI is now the ultimate tool to aid and leverage the level of prediction of emerging threats.

Implementation Challenges and Considerations

Implementing ZTA can sit somewhere between a relaxed sensation of increased security and a nightmare when it comes to increased costs and degraded user experience, having a serious impact on the organization’s business flow. Let’s take a look into some aspects.

• Organizational Culture: Adopting a Zero Trust mindset requires a cultural shift within organizations, as it challenges traditional notions of trust and access privileges.

• User Experience: Striking a balance between security and usability is essential to avoid impeding productivity and frustrating users with excessive authentication prompts and access restrictions.

• Legacy Infrastructure: Legacy systems and applications may not be designed with ZTA principles in mind, making their integration into a Zero Trust environment challenging. Typically, this is the kind of infrastructure that sits in ‘onprem’ data centers and has a perimeter protection approach. Moving to a ZTA-based approach does not mean that you can forget, or do not invest further in perimeter security, but it means that maybe you can reduce the secured area. Depending on the nature of the data and the organization’s activities, it may be a good opportunity to reduce the scope of the trusted networks and instead of buildings and campus; you only need to secure the data center. Anything outside DC it’s the 'internet,' which is the same as saying–untrusted. But remember this per se it’s not a validation that someone that managed to get inside the perimeter is “trusted”. 

This is where the real challenge begins when it comes to legacy components. Nevertheless, I have seen several business cases where this shift and adoption of edge zero-trust client software packages turned out to be a cost reduction.

• Cloud Approach: As an opposite to legacy infrastructure, most cloud loads are deployed with most of these concerns by design. It means they implement things like Identity and Access Management (IAM), multi-factor authentication (MFA), rolebased access control (RBAC), and conditional access. This can be used by applications, servers and services in order to offload part of the process, by using Single Sign on (SSO) and the users particularly appreciate the SSO functionality.

So, one option to consider is to take advantage of these technologies to improve legacy or on-prem-based systems. I am pretty sure that most organizations are nowadays “hybrid and multi-cloud”. They have their data spread or spanned across these layers. So, one option to consider is to “route” access through the mechanisms stated above present in most cloud offerings, into your legacy or on-prem applications and data. Technically, what is there to do, is tunneling the access to onprem from your cloud provider via a secure (and preferably dedicated) connection. All application and data accesses are then established via this tunnel after the user, device or application has gone through all the authentication and authorization processes, the behavioral assessment and other mechanisms in order to ensure the key principles stated above. There are several wordings for this, but the one I like the most is “application proxy” because that’s exactly what it does in simplistic terms. Together with a ZTA software client installed on your device, you can transparently access and use your applications and data, take advantage of SSO, and have a better user experience despite the significant leap in security.

In conclusion, we know cyber-attacks continue to evolve in sophistication and frequency, ZTA offers a proactive and adaptive approach to securing modern IT infrastructure in an increasingly interconnected world. By embracing the principles of Zero Trust, organizations can build resilient defenses against emerging cyber threats and safeguard their most valuable assets in the digital age.