What is Zero Trust Security?
Any user or device attempting to access network resources, regardless of where they are (inside or outside the network perimeter), must undergo stringent identity verification according to the zero-trust security framework. Removing built-in trust from the network and demanding constant verification for all access attempts marks a dramatic departure from conventional castle-and-moat security models.
Traditional Castle-and-Moat vs. Zero Trust Security
Traditional network security relies on a “castle-and-moat” concept, where strong perimeter defenses make it difficult to gain access from the outside. However, once inside, users and devices are trusted by default. This approach has several vulnerabilities:
Lateral Movement: If an attacker breaches the perimeter, they have free rein to move laterally within the network and access sensitive data.
Unsuitable for Modern IT Environments: Modern IT environments with remote workforces, cloud storage, and diverse device usage render the traditional perimeter-based approach ineffective.
Zero Trust security addresses these shortcomings by adopting a “never trust, always verify” approach. Here’s a breakdown of the core principles:
Continuous Monitoring and Validation: Zero Trust assumes threats can originate from both inside and outside the network. User identities, device health, and access requests are continuously monitored and validated.
Least Privilege Access: Users are granted only the minimum level of access required to perform their tasks. This minimizes the potential damage if credentials are compromised.
Device Access Control: Strict controls are placed on device access. Network systems monitor and verify every device attempting to connect, ensuring authorization and assessing potential compromise.
Microsegmentation: The network is segmented into smaller zones with independent access controls. This limits the blast radius of a breach, preventing attackers from easily moving laterally.
Multi-Factor Authentication (MFA): MFA requires users to provide additional verification factors beyond a simple password, significantly enhancing login security.
Benefits of Zero Trust Security
1. Reduced Attack Surface
By limiting access and continuously verifying users and devices, Zero Trust security minimizes the attack surface for potential threats.
2. Breach Containment
Microsegmentation helps contain breaches, preventing attackers from easily accessing other parts of the network.
3. Reduced Impact of Credential Theft
MFA reduces the effectiveness of stolen credentials as a means of gaining unauthorized access.
4. Improved Security for Cloud and Remote Work
Zero Trust is well-suited for modern IT environments with cloud resources and remote workers.
Zero Trust vs. Agent-based Security
While both approaches offer network security, they differ in their implementation:
Zero Trust: Focuses on verifying access requests, leveraging existing protocols and APIs for data collection. Offers a lightweight and scalable approach.
Agent-based Security: Relies on dedicated software agents installed on devices for deeper monitoring and data collection. Can be more complex to deploy and manage but may provide richer data.
Zero Trust Network Access (ZTNA)
ZTNA is a key technology that enables Zero Trust security. Similar to a software-defined perimeter (SDP), ZTNA creates secure, one-to-one encrypted connections between devices and the specific resources they need, further enhancing access control.
Common Use Cases for Zero Trust Security
Zero Trust offers benefits across various IT security scenarios:
Replacing or Augmenting VPNs: VPNs can be cumbersome and offer limited protection against modern threats. Zero Trust provides a more secure and flexible alternative for remote access.
Secure Remote Work: Zero Trust facilitates secure access control for remote workers, eliminating the need for VPNs and their associated bottlenecks.
Cloud Access Control: Zero Trust verifies all access requests, regardless of their source or cloud destination. It can also help identify and control unauthorized cloud services (shadow IT).
Onboarding Third-Parties: Zero Trust enables secure, least-privilege access for external parties like contractors, who often use unmanaged devices.
Rapid User Onboarding: Zero Trust simplifies onboarding new employees by streamlining access control processes.
Best Practices for Implementing Zero Trust Security
Monitor Network Traffic and Devices: Maintain constant visibility into network activity and connected devices to facilitate user and device verification.
Patch and Update Devices Regularly: Unpatched vulnerabilities create security gaps. Zero Trust should restrict access from compromised devices.
Enforce Least Privilege: Limit user access to the minimum required level across the organization.
Segment the Network: Partition the network to contain breaches and prevent lateral movement. Microsegmentation is a recommended approach.
Eliminate Perimeter-Centric Thinking: Modern networks often have numerous connections to the internet and cloud, making a singular perimeter impractical.
Utilize Hardware-Based MFA: Security keys offer stronger protection compared to software-based tokens like one-time passcodes.
Maintain Threat Intelligence: Stay updated on evolving cyber threats by subscribing to threat intelligence feeds. This knowledge helps proactively identify and address potential security risks.
Balance Security with Usability: Overly stringent security measures can frustrate users and lead to workarounds that weaken security. Strive for a balance between robust protections and a user-friendly experience.
Implementing Zero Trust Security
While Zero Trust may appear complex, the adoption process can be streamlined with the help of the right technology partner. Many Security Access Service Edge (SASE) platforms combine networking services with built-in zero-trust access control for users and devices. These platforms can automate Zero Trust implementation and extend protection across all network assets and data.
History of Zero Trust Security
The concept of Zero Trust security emerged in 2010, coined by an analyst at Forrester Research. A few years later, Google’s implementation of Zero Trust within their network sparked significant industry interest. By 2019, Gartner recognized Zero Trust security access as a core component of SASE solutions.