How out of band communication strengthens zero trust security frameworks

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Just like flipping a coin, the more we advance with digital tools, the more cyber threats we face. It’s a constant trade-off. That’s why enterprises are adopting out of band communication to lock down critical systems and secure communication.

Moreover, would you believe your network is safe just because no alerts popped up? Or would you verify it? 

Zero trust operates on the same principle: assume nothing, verify everything. If you don’t continuously validate your systems, breaches can happen without warning.

In 2024, the average cost of a data breach reached $4.88 million - a 10% increase from 2023. Experts argue that traditional security measures are not adequate for evolving threats.

However, out of band communication can reinforce the zero trust framework. Even if attackers breach your primary network, they can’t compromise your control systems. 

Read on to see how OOB keeps your organization resilient against breaches.

Why zero trust needs dedicated out of band channels

Do you rely on Slack or Microsoft Teams to manage security incidents? While these platforms are secure and adequate, there’s one problem:

If attackers breach your network, they can control these platforms too. They can intercept alerts, block responses, and manipulate IT teams into thinking everything’s fine.

What MGM’s security failure teaches about cyber resilience

For example, cybercriminals posed as a current MGM employee and gained admin access to Okta and Azure environments. Though MGM deactivated key systems, attackers had enough access to deploy ransomware on 100+ ESXi hypervisors, crippling operations.

This breach forced MGM to shut down its reservation systems and critical operations for 10 days, costing the company $8.4 million per day.

MGM faced multiple lawsuits for failing to protect personally identifiable information, despite Okta's warnings about targeted social engineering attacks.

Can out of band communication channels prevent social engineering tactics? No, but they can prevent attackers from controlling the response once they’re inside. Here’s how:

• If MGM’s security team had an OOB system, they could have coordinated responses without attackers listening in.
• OOB shares critical alerts to decision makers, even if hackers disable or delay alerts in compromised systems.
• OOB channels can verify high-risk actions separately, providing stronger multi-factor verification.

Embedding out of band communication in zero trust

Out of band communication is a critical pillar of zero trust security, ensuring attackers can’t manipulate endpoints and intercept sensitive data. To embed OOB effectively, follow these key strategies:

User authentication and authorization

With traditional authentication, attackers can steal credentials and hijack sessions, but OOB verifies users through a separate, secure channel, preventing unauthorized access.

Even if you use MFA, it’s not foolproof if it relies on SMS, email, or other easily intercepted methods.

Verizon’s 2023 DBIR found that 49% of breaches by external actors involved stolen credentials and 41% of breaches affected mail servers.

Note that if an attacker gets access to your inbox, they can reset passwords and bypass MFA.

In contrast, OOB with advanced MFA uses independent channels like hardware tokens and secure mobile authenticator apps, making it harder to intercept.

Need for continuous verification and privileged access

Zero trust takes a step further by constantly verifying users, not just at login. Embedding OOB triggers additional verification based on risk levels.

For example, Google’s Advanced Protection Program forces high-risk users to verify actions through a separate physical device, reducing unauthorized access attempts.

Device and endpoint security

Endpoints can be easily exploited through advanced phishing and malware. Out of band security mechanisms add an extra layer of protection by: 

• Remote attestation: Verifying the integrity of a remote device's hardware and software configurations through independent channels. This helps detect unauthorized changes and system compromises.
• Hardware security modules: Managing cryptographic operations using isolated OOB channels. This ensures encryption keys remain protected even if the main network is compromised.

Many businesses are already adopting Hardware Security Modules (HSMs) to safeguard sensitive data. The global HSM market was valued at USD 1.56 billion in 2023 and is anticipated to grow at a CAGR of 16.3% from 2024 to 2030.

Additionally, recent research explores multi-channel deep attestation methods for independently verifying virtual machines and hypervisors. 

Studies from universities and industry researchers highlight that hypervisors can provide the public key of the virtual machines they manage, enabling stronger linking and verification.

One study specifically presents a scalable approach for collective remote attestation in NFV environments.

With growing cyber threats, the demand for secure authentication and encryption solutions continues to rise.

Secure boot verification through OOB channels

Even with a secure boot, attackers can manipulate primary systems to inject unauthorized firmware. OOB verification strengthens this process by:

• Authenticating firmware through an independent, tamper-resistant channel.
• Preventing boot-level malware from compromising system security.

Network segmentation and monitoring

Attackers can bypass a flat network structure and move laterally once they gain access. OOB monitoring and segmentation strengthen security by isolating critical systems and detecting anomalies in real-time.

Moreover, OOB provides a dedicated control plane for managing firewall rules, access control, and incident response without interference.

Micro-Segmentation for OOB Communication Infrastructure

In a zero trust architecture, isolating network zones further limits an attacker’s ability to move laterally. When you combine micro-segmentation with OOB, you can:

• Restrict lateral movement: Even if an endpoint is breached, attackers cannot easily access other segments.
• Enforce least privilege access: Systems only communicate with what’s necessary, reducing exposure.
• Enhance OOB authentication: Secure enclaves can verify access requests before granting permissions.

Micro-segmentation and OOB communication align with zero trust principles by enforcing strict access controls and continuously monitoring user activity.

Researchers emphasize that you must evaluate your network architecture and access policies to implement an effective zero-trust model across dynamic environments.

Data protection and access controls

Attackers always find ways to breach data even with strong access controls. They exploit weak key management, insider threats, and control plane vulnerabilities. 

Out of band communication strengthens security by keeping encryption keys, access approvals, and control mechanisms separate from the main environment. This limits access and reduces the risk of compromise.

Why separate the data plane from the control plane

Separating the data plane from the control plane is a fundamental security measure to enforce stricter access controls and reduce the risk of unauthorized access.

For example, Google Cloud’s External Key Manager secures encryption keys in an independent security module, and it’s not easy for attackers to steal them, even if they breach cloud resources. 

Cloud resources are the biggest targets for cybercriminals. According to the 2024 Thales Cloud Security Report:

• 30% target cloud storage
• 31% of attacks target SaaS applications
• 26% target cloud management infrastructure

The most worrisome insight is that most cloud data remains unencrypted.‍

On average, 47% of data stored in the cloud is sensitive, yet less than 10% of enterprises encrypt at least 80% of their cloud data.

While 65% of organizations say cloud security is a top priority, securing cloud workloads requires a stronger approach. 

Integrating out of band communication with zero trust ensures strict control over encryption keys. This can help minimize risks even in the case of a breach.