What is a Software Defined Perimeter?

Software-defined perimeter (SDP) is a network infrastructure with remote capabilities to protect cloud-based and on-site data centers. The goal of an SDP approach is to use software as the basis for the network perimeter, not hardware.  The Cloud Security Alliance established the SDP in 2013 as a solution for robust networks that reduced the risks of data breaches. 

SDPs are effective in the modern IT landscape, where companies have data management spread across various channels, including public and private cloud systems. The SDP infrastructure provides IT managers with a single security control for both remote and on-site networks. 

The infrastructure of SDPs differs from perimeter-based networks by restricting broad network access. Instead, SDP provides users with strict access to specific services and hosts defined by a predetermined policy.  As such, SDPs significantly reduce the network attack surface of an organizational IT system and prevent malicious attacks. This infrastrucutre helps lay the foundation for a Zero Trust approach, a security paradigm that combines strict identity verification and explicit permission for every person or entity attempting to access or use network resources, regardless of whether the person or entity is in “inside” an enterprise’s network perimeter or accessing that network remotely. By taking away access from anyone and everyone until the network verifies identitiy, adopting a Zero Trust approach allows you to continuously montior how your data is accessed and used.  

SDPs are more secure alternatives to conventional perimeter-based networks. The infrastructure supports a zero-trust protocol, where every user is denied access by default and requires a stringent verification process. SDP verifies access through a two-step approach, which includes user identities and devices. 

SDPs restrict User network access to a need-to-know basis, establishing private dedicated connections between users and servers. The network is location and infrastructure-agnostic, enabling IT experts to deploy gateways from anywhere to monitor user activities remotely. SDP’s flexibility supports global implementation and the customization of automated access policies. 

An SDP approach ensures that any and all endpoints attempting to access a resource are authorized and authenticated before being granted access to any assets on the network. Software-defined perimeters authenticate user identities through a password and username combination or a multiple authentication process for added security. Devices are checked for the latest updates and scanned for malware threats and related security risks. 

SDP ensures that devices are valid and authorized, which is crucial in a BYOD (bring your own device) workplace where employee systems may be compromised. Software-defined perimeters also eliminate the security risks from IoT devices that are easily accessible from third-party sources. SDP’s dynamic functions connect users to any application through a process without tedious management processes while maintaining strict access to required IT resources. 

The stringent authentication process attempts to reduce cases of network attacks, such as advanced persistent threats and man-in-the-middle, which are responsible for serious data breaches.

Each user needs to authenticate their identity and device before access, within, or beyond a network. SDP usually collects the information from a third-party identity provider (IdP) before conveying the details to the SDP controller. Once the user and device are authenticated, an individual network connection is established between the device the server.

The SDP controller is the logical component of the network that validates the provided information through a mutual TLP (transport layer security). Mutual TLPs are network security protocols that authenticate the legitimacy of users and service providers before enabling a safe encrypted connection. 

SDP gateways grant access to users upon confirming authentication from the controller. The established connections are exclusively accessible by authenticated user and service providers. Once an individual network connection is established, a user can access the Internet, but no other user can access that individual network and the network connection only includes the assets that the user has approved access to.

VPNs (virtual private networks) provide an encrypted connection over usually unencrypted channels, mimicking a private network. The VPN strategy provides an additional security layer in organizational user access but remains vulnerable to data breaches. 

Additionally,  VPNs may be impractical in multi-level access scenarios where users need to set up separate VPNs with each extra connection. Hacked VPN credentials pose the same risks as compromised organizational networks, where malicious users have free reign over data centers. Multiple VPNs lead to complex IT management routines, which increases the chances of data breaches. 

Alternatively, SDPs are more secure than VPNs, as they establish unique connections between users and servers, enforced with restricted access for every login. Additionally, an SDP’s dual-authentication process prevents unauthorized access even with compromised login credentials or stolen devices. Some SDPs have the capabilities of a built-in blacklisting system that immediately deny the access requests from unauthorized devices.

A core pillar of SDP is the ability to leverage microsegmentation to grant the least privileged access to the network. This infrastructure is the basis for building a Zero Trust approach. Forcepoint’s continuous Zero Trust security goes beyond a simple SDP and allows users to control the usage of data—not just access.