Why Perimeter Security Is No Longer Enough

What is Perimeter Security?

Perimeter security is the traditional model for preventing external attackers from accessing the corporate network. Security measures like firewalls and intrusion detection and prevention systems would act like security checkpoints, similar to physical perimeters like walls and doors. This solution was a good fit for legacy architecture and traditional networks. But nowadays, with the evolution of cloud computing, networks and IT environments, this model is no longer sufficient. Let’s see why, and how the zero trust security framework can help.

Perimeter Security – Protecting Legacy Networks from External Actors 

For years, organizational cybersecurity was focused on securing internal data and systems from external attackers. Businesses established data centers with in-house IT infrastructure that included servers, client devices, internal networks, internet gateways and applications. This infrastructure held almost all the organizational business information required for business continuity. Firewalls, demilitarized zones, antivirus programs and intrusion systems protected these assets, creating a clear border between those who were allowed access and those who weren’t.

Any user who had access to the network could access large parts of it, regardless of their job title or actual needs. This design was due not only to the network structure but to the workforce structure as well. Most if not all employees worked on-premises, and organizations scarcely ever supported remote work plans. Trying to access network assets remotely was a difficult process, with the perimeter security model treating remote workers as though they were intruders trying to access the crown jewels.

The Modern Network Perimeter is Full of Holes

Perimeter-based security solutions were sufficient for their time, when businesses mostly required local network operations and employee connectivity to networks took place exclusively in the office. However, digital transformation and societal changes revolutionized network architecture and dissolved the perimeter. These changes include:

1. Cloud Computing Adoption

Modern enterprises prioritize digital transformation that is based on cloud infrastructure and services. Information, data and systems are no longer stored on-premises, but rather in external cloud data centers, which sometimes reside in a completely different country, or through a hybrid cloud.

As a result, employees can access the organizational information and apps they need from any location or device, businesses can easily scale and information is shared more easily. However, this also means that the perimeter is completely dissolved, as the businesses have no control over the cloud.

2. COVID-19 and Remote Work

COVID-19 rapidly accelerated the adoption of remote work, making it difficult for organizations to define and secure IT environments using perimeter security models. With a recent Gartner study revealing that 74 percent of organizations intend to shift some employees to remote work permanently, it is apparent that a perimeterized workforce will become obsolete.

However, even before COVID the workforce had shifted. People were already working from home, or perhaps more accurately, also working from home or elsewhere outside the office. They were connecting from various mobile devices, home offices, airports, restaurants, and additional edges. They were speaking with users around the globe. And they needed access to organizational networks at all times of day and night. As a result, security solutions needed to evolve as well to account for this agile and ‘always on’ workforce. 

3. The Demise of VPNs

As remote work and cross-branch connectivity requirements grew, enterprises initially relied on VPNs to provide remote workers with the ability to perform tasks securely while away from the office. Today, many businesses still resort to VPNs to enable secure remote connections. However, in light of a number of high-profile VPN breaches, the realization that VPNs still operate according to the perimeter-based security model by tunneling in remote users, and a demand for high performance and low latency, enterprises are looking elsewhere for a more secure and easy to use security solution.

The Shift from Perimeter Security to Zero Trust Models

As we’ve just described, today’s network perimeter is full of holes, and access points are vulnerable. Migrating to a more modern zero-trust model can help organizations improve their security posture. In this model, the basic assumption of trust is replaced with the “never trust, always verify” principle. With no more inherent trust, users and devices are continuously authenticated every time they request to access an app or asset. Instead of immediately providing access to each identity, methods like multi-factor authentication (MFA) and single sign-on (SSO) will ensure that only users who require access to a certain resource will gain it.

Zero trust architecture enhances security because it protects the network from external attackers. At the same time, the model also assumes there are already attackers inside protects against these as well. Overall, implementing the zero trust framework improves organizational security while also providing workers with more flexibility regarding when, how, and where they access the systems needed to do their jobs.