SSE Architecture Explained: How SSE Enables Zero Trust

A security service edge (SSE) architecture consolidates network security tooling and technologies. It continuously verifies that least-privileged access control is applied to every user session, and applies those access control policies across every physical location. 

SSE also enables zero trust enforcement at scale. Security service edge enforces the "never trust, always verify" principle by analyzing every access request in real time. Once an access request is analyzed, SSE requires explicit user authentication and device posture validation before it grants access to a single resource.

What is an SSE architecture?

An SSE architecture is a cloud security framework that combines secure web gateway (SWG), cloud access security broker (CASB), and zero trust network access (ZTNA) into a single policy engine. The framework also includes the deployment models, traffic flows, control points, integrations, and operational choices that your organization makes to deliver those SSE capabilities.

SSE architectures steer traffic from endpoints, branch sites, or cloud workloads to the nearest point of presence (PoP). At the PoP, SSE applies identity- and context-aware policy.

SSE platforms evaluate multiple signals to allow, block, inspect, or broker access. These signals include user identity, device posture, content, application, and risk. SSE platforms also offer TLS/SSL inspection, malware scanning, and inline or API-based SaaS controls.

Why are SSE architectures important?

SSE architectures consolidate SWG, CASB, and ZTNA policy engines, data classification layers, and management consoles into one solution. With SSE, security teams can define and enforce consistent policy across all traffic types.

SSE architectures move the enforcement point away from the corporate perimeter to the cloud itself. Traffic inspection, threat detection, and access control happen in globally distributed PoPs. As a result, policies are enforced at the edge, where users are. Security teams can respond faster to threats, and users experience less latency.

Core SSE components

SSE architectures include two elements: a complete SSE platform and core operational components. These core components include:

How AI enhances SSE architectures

AI and machine learning shift SSE architectures away from static and rule-based policies to a dynamic and predictive approach. AI in SSE addresses issues like zero-day attacks, noisy alerts, and suspicious activity.

• Inline threat protection uses machine learning models and behavioral analysis to detect novel threats like phishing attacks.
• AI discovers and classifies data in real time. Machine learning models trained on your company’s data patterns cut down on false positive alerts.
• User and behavior analytics (UEBA) learns what baseline activity looks like in your environment. It can detect behavior that rule-based policies miss, like abnormal data transfers or suspicious access patterns.
• SSE continuously updates each user’s risk score and automatically adjusts user permissions based on behavior, device health, and login history. If the risk score increases, SSE revokes access or requires reauthentication.
• AI reviews traffic logs and recommends policy changes based on real-world usage and risk.

How does SSE enable zero trust? A step-by-step overview

SSE enforces zero trust principles through a combination of its integrations and its SWG, CASB, and ZTNA functionality. 

Here's what SSE does in real time when a user requests access to an app:

1. Verify user identity. When a user requests access to an application, SSE uses its integration with an IdP to authenticate that user via MFA.

2. Assess device posture. SSE checks the user’s device for any health or compliance issues. For example, if the device has an out-of-date OS or lacks necessary patches, SSE will block or restrict that device’s access.

3. Enforce least-privileged access. SSE checks the user’s role, device type, and location to enforce the correct access policy.

4. Replace traditional network access with ZTNA. Rather than placing the user on a broader network, SSE establishes a ZTNA connection directly to the application.

5. Inspect all traffic inline. SSE implements TLS/SSL inspection on all traffic. The platform scans encrypted and unencrypted traffic for malware, phishing, and policy violations. 

6. Apply inline threat prevention. SSE blocks malicious content, unauthorized SaaS apps, and other threats before they reach the user or application.

7. Control cloud and SaaS app activity. SSE manages how users engage with sanctioned and unsanctioned cloud apps. For example, SSE can restrict Salesforce access to the sales team or limit Google Drive files to read-only for contractors. 

8. Monitor user behavior. The platform includes user and entity behavior analytics (UEBA) and logging capabilities, which identify what normal behavior looks like. SSE catches deviations from the norm like bulk data downloads and logins from different countries.

9. Change or revoke access based on real-time risk. When SSE detects anomalous behavior, it immediately takes action to isolate the threat.

10. Complete audits and implement incident response. SSE collects telemetry across traffic, users, and applications to create an audit trail. Your security team uses this data to program automated responses, investigate incidents faster, and update policies.

What zero trust outcomes does SSE help deliver?

Security service edge delivers the following zero trust outcomes: 

• Least-privileged access: Users and apps get access to only what they need, and nothing more.
• Continuous verification: Uses identity, risk, and device posture signals to reverify access.
• Reduced attack surface: Applies consistent web and SaaS controls and uses ZTNA to reduce the risk of lateral movement.
• Consistent policy applied everywhere: The same rules apply whether users are at the office or working remotely.
• Threat prevention applied at the edge: Inspects traffic, blocks malware, and proactively identifies risky behavior.
• Improved visibility and auditability: Unified logging and analytics make investigation and compliance reporting faster and easier.

SSE: The first step in your zero trust journey

Zero trust assumes that no one inside or outside of your network should be trusted by default. It takes time to move towards zero trust, and for most organizations SSE represents an accessible starting point for that evolution. 

As you mature your zero trust architecture and SSE program, you'll find that deploying secure access service edge (SASE) is a natural next step. 

Bringing together networking and security using a SASE model makes zero trust possible for scaling teams. Zero trust demands continuous verification and policy enforcement, and SASE delivers the unified infrastructure needed to make that possible. 

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