BlastShield is BlastWave’s Zero Trust network access solution for OT environments. It uses a software-defined perimeter approach to help organizations reduce risk from stolen credentials, simplify access control, cloak critical systems, secure remote access, and segment OT networks.

How does BlastShield help stop OT attacks before they start?

BlastShield helps stop OT attacks before they start by requiring authentication and authorization before users or devices can access protected systems. It combines network cloaking, phishing-resistant access, secure remote connectivity, and software-defined segmentation to reduce exposure and limit lateral movement.

What is the BlastShield Security Gateway?

The BlastShield Security Gateway is a hardware-independent software package that can be installed in a VM, container, or pre-installed appliance. It delivers network cloaking, terminates secure remote access connections, and uses software-defined segmentation to secure OT networks.

What is the BlastShield Client?

The BlastShield Client is a Zero Trust client for secure OT connectivity. It supports Windows, Mac, and Linux, allowing authorized users to connect securely to approved OT systems without disrupting existing operations.

What is the BlastShield Authenticator?

The BlastShield Authenticator provides passwordless authentication using a QR code challenge-response, localized biometric authentication, and the device keystore. It is designed to prevent credential theft, phishing, and AI-powered attacks while keeping a human in the loop.

BlastAccess is BlastWave’s secure remote desktop connectivity solution. It provides high-performance remote access with session recording, while removing open ports and reducing risks from browser hijacking, password theft, PAM weaknesses, and web-based RDP exposure.

What does the BlastShield Agent do?

The BlastShield Agent helps secure servers by requiring a verified BlastShield client before a connection can be made. It supports Windows, Mac, and Linux and helps turn protected servers into Zero Trust-controlled assets.

What does the BlastShield Orchestrator do?

The BlastShield Orchestrator manages real-time policy enforcement across the network. It can be deployed on-premises or in the cloud and helps ensure users and devices connect only to the systems they are authorized to access.

How does BlastShield support network cloaking?

BlastShield supports network cloaking by requiring users and devices to authenticate and authorize before access is granted. This helps make protected systems non-discoverable to unauthorized users and reduces the value of reconnaissance.

How does BlastShield support OT network segmentation?

BlastShield supports OT network segmentation through software-defined access controls that divide the network into isolated segments. This limits lateral movement and helps contain the impact of a breach.

How Do I Protect All My OT Devices — Whether I Know What They Are or Not?

OT Asset Security

How Do I Protect All My OT Devices — Whether I Know What They Are or Not?

You can't protect what you can't see. And in most OT environments, 15–30% of networked devices aren't in anyone's asset list. BlastShield discovers and protects every communicating device — including the ones you didn't know were there.

Close the Attack Surface

See Compliance Mapping

15–30%

of OT devices are unknown to security teams

27%

of OT incidents involve unmanaged or transient devices

100%

of communicating devices visible in BlastShield

The OT Asset Visibility Problem: You Don't Know What You Have

Every security framework starts with asset inventory — you cannot apply security controls to assets you don't know exist. Yet in OT environments, maintaining an accurate, complete asset inventory is one of the hardest unsolved operational challenges. OT networks are built over decades, with devices added, modified, and sometimes abandoned without documentation. Change management processes that are rigorous in IT are often informal or non-existent in OT.

The result: security teams routinely discover devices on OT networks that have been operating, undocumented, for years — sometimes decades. These unknown devices represent unmanaged attack surface: unpatched firmware, default credentials, no logging, and no place in anyone's incident response plan.

The blind spot reality: In a recent study, OT security practitioners reported that between 15% and 30% of devices on their OT networks were not in their asset inventory. On a network with 1,000 OT assets, that's 150–300 devices receiving zero security controls — any one of which could serve as an attacker's entry point or persistence mechanism.

Why Traditional IT Segmentation Tools Don't Work in OT

Vendor-Installed Equipment

Maintenance laptops, configuration tools, or access gateways left behind by vendors after a service visit — connected to OT network segments and forgotten.

Shadow IoT Sensors

Smart environmental sensors, condition monitoring devices, or wireless meters added by operations staff without IT/security approval or documentation.

Obsolete Systems

Legacy servers, HMIs, or workstations that were "decommissioned" but never disconnected — still powered on, connected, and potentially reachable by attackers.

Undocumented PLCs

Control devices added during production line expansions or facility changes years ago that never made it into the asset management system.

Unauthorized Personal Devices

Operator smartphones, personal laptops, or tablets connected to OT network segments for convenience — bypassing all security controls.

Rogue/Attacker Devices

Devices intentionally placed by attackers for persistence — network implants, compromised hardware, or malicious USB-based devices dropped on the OT network.

Why Traditional Security Models Fail for Unknown OT Devices

Most OT security tools are built around the assumption that you have a known asset inventory. Vulnerability scanners assess vulnerabilities in devices you tell them about. Patch management systems update devices you've enrolled. Endpoint security agents run on devices you've provisioned. None of these approaches help with a device you don't know exists.

Traditional Approach

Security controls applied to a static asset list
Unknown devices have no security controls
Active network scans can crash OT devices
Rogue devices operate undetected indefinitely
Vendor equipment left on network unnoticed
Inventory drift grows over time

BlastShield Approach

Passive discovery finds every communicating device
Unknown devices are isolated by default
No active scanning — zero disruption to OT
New devices trigger immediate alerts
Vendor sessions controlled and time-limited
Continuous discovery keeps inventory current

Why Active Scanning Doesn't Work in OT

In IT environments, network discovery typically uses active scanning — sending packets to every IP address and analyzing responses. In OT environments, this approach is dangerous. Many PLCs, RTUs, and industrial controllers were not designed to handle unexpected network traffic. An active scan can cause a PLC to fault, an HMI to freeze, or a safety system to trigger an emergency stop. CISA has specifically warned against using active scanning tools on live OT networks for this reason.

Passive discovery — observing network traffic without injecting test packets — is the only safe approach for OT asset inventory on live production networks.

How to Protect All OT Devices — Known and Unknown

The solution requires fundamentally changing the security model: instead of building an inventory and then securing the inventory, you secure the network first and then identify what's on it. Default-deny network policy ensures that unknown devices are isolated from the moment they appear — before they can be exploited.

Deploy Passive OT Asset Discovery

Implement continuous passive network monitoring that identifies every device communicating on your OT network — based on traffic patterns, protocol signatures, ARP tables, and behavioral fingerprinting — without sending a single active scan packet. This provides a complete, continuously updated inventory of all OT assets, including those that were never documented. BlastShield's passive discovery is designed specifically for OT protocol environments (Modbus, DNP3, EtherNet/IP, BACnet) and does not risk disrupting OT operations.

Implement Default-Deny Network Policy for Unrecognized Devices

Any device that appears on the OT network without an authorized profile should be automatically isolated — unable to communicate with any other OT asset, reach the internet, or receive inbound connections. This default-deny posture means that unknown devices, whether benign or malicious, cannot cause harm while they are being investigated and classified. In a zero-trust OT architecture, network access is earned through authorization, not assumed from network presence.

Alert on New Device Appearance

Every new device that appears on the OT network — even during authorized maintenance windows — should trigger an immediate alert to the security team. The alert should include the device's IP address, MAC address, observed protocol behavior, vendor fingerprint (if identifiable), and the network segment where it appeared. Security teams should have a defined process for rapidly classifying and authorizing or removing new devices.

Apply Uniform Protection Policy Regardless of Device Knowledge

Once a device is discovered — whether it was in the original inventory or not — apply consistent security policy: network cloaking from unauthorized access, microsegmentation limiting its communications to only what it requires, and continuous behavioral monitoring for anomalies. A discovered-but-previously-unknown PLC receives the same protection as a documented, well-known controller. The security posture does not depend on prior knowledge of the device.

Control and Audit All Transient Device Access

Vendor laptops, contractor tablets, and portable test equipment represent high-risk transient devices that may connect briefly and then leave — but the access they created may persist. Implement explicit policies for transient device access: pre-authorization of the device, time-limited access scoped to specific OT assets, session recording, and automatic revocation when the maintenance window ends. BlastShield manages vendor and contractor access with device-specific, time-bounded sessions that cannot be reused or extended without re-authorization.

The zero-trust inversion: Traditional OT security assumes everything on the internal network is trusted until proven otherwise. Zero-trust OT security assumes everything — known or unknown — is untrusted until explicitly authorized. This single architectural inversion eliminates the unknown device problem: an undocumented PLC receives no more implicit trust than a rogue device placed by an attacker.

How BlastWave Protects Every Device — Even the Ones You Don't Know About

BlastShield was built on the recognition that OT asset inventories are never complete and never current. Rather than requiring a perfect inventory as a prerequisite to security, BlastShield provides protection at the network access layer that applies to every communicating device — regardless of whether it appears in any asset management system.

Continuous Passive Discovery

BlastShield continuously monitors OT network traffic, building and maintaining a real-time inventory of every device on the network. Device fingerprinting uses protocol analysis, behavioral patterns, ARP traffic, and vendor-specific signatures to identify device type, vendor, firmware version (where observable), and communication patterns — all without sending any packets to OT devices. When a new device appears, BlastShield immediately alerts security teams and applies isolation policy until the device is classified and authorized.

Protection Before Classification

An unknown device that appears on the OT network is isolated immediately — before the security team even knows it exists. BlastShield's default-deny policy means that an undocumented device cannot communicate with your PLCs, your historians, or the internet while it is being investigated. The attacker's device placed during a maintenance visit cannot call home. The forgotten legacy server cannot be used as a lateral movement pivot. Unknown means isolated.

Agentless Protection for Every Device Type

BlastShield requires no agent, no firmware modification, and no device configuration change. A 20-year-old PLC, a consumer-grade IoT sensor, a vendor's diagnostic laptop, or a SCADA historian from 2003 — all receive full protection through network-layer policy enforcement. The diversity of OT device types, vendors, and protocols is not an obstacle to protection; it is irrelevant to a network-layer security model.

Frequently Asked Questions

How do I protect OT devices that aren't in my asset inventory?

Passive network discovery identifies every device communicating on your OT network, including those not in your inventory. BlastShield applies default-deny isolation to unrecognized devices immediately, preventing them from communicating with authorized OT assets while they are investigated and classified. You receive complete visibility and automatic protection for unknown devices without needing to update an asset list first.

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What is passive OT asset discovery and why is it safer than active scanning?

Passive discovery observes network traffic without sending probe packets to OT devices. This is essential in OT because active scanning tools (Nmap, vulnerability scanners) can crash or disrupt PLCs and RTUs that are not designed to handle unexpected connection requests. Passive discovery is completely invisible to OT devices — it analyzes traffic they generate during normal operation, building a device inventory without any operational risk.

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How do I handle devices that are on the network but haven't been authorized?

BlastShield's zero-trust model isolates unrecognized devices by default — they cannot communicate with authorized OT assets until explicitly approved. When a new device appears, security teams receive an alert with all available device information (IP, MAC, protocol behavior, vendor fingerprint). The team then classifies the device as authorized (and assigns appropriate access policy) or removes it. This process prevents unrecognized devices from operating as security risks while investigation proceeds.

Can a compromised OT device spread malware to other devices I'm not aware of?

In a flat, unsegmented OT network, yes. A compromised device can scan and communicate with any other device on the same network segment, including undocumented ones. BlastShield's microsegmentation prevents this by ensuring that even authorized devices can only communicate with the specific assets their operational role requires. A compromised PLC cannot scan for other PLCs, reach historian servers, or communicate with devices outside its defined segment — whether those devices are documented or not.

How do I manage vendor and contractor devices that connect temporarily to my OT network?

BlastShield manages transient device access with pre-authorization, time-bound sessions, and automatic revocation. A vendor's laptop is authorized for the specific maintenance window, scoped to the OT assets the vendor needs to reach, and automatically disconnected when the window ends. The device cannot be reused for another session without re-authorization. All session activity is logged for audit. This eliminates the "vendor backdoor" problem that affects many OT environments with traditional VPN-based remote access.

Does BlastShield work on all OT protocols and device types?

Yes. BlastShield's network-layer protection is protocol-agnostic — it applies to any networked device regardless of the protocol it uses (Modbus, DNP3, EtherNet/IP, BACnet, OPC, Profinet, or any other). Device type, vendor, age, and operating system are irrelevant to the protection model. For discovery, BlastShield understands common OT protocol signatures to provide richer device fingerprinting, but unknown protocols are still discovered and isolated by default. See our related pages on protecting legacy OT systems and preventing OT internet exposure for additional context.

See Every Device.
Protect Every Device.

BlastShield discovers and secures every device on your OT network — including the ones not in your asset list. See your full OT attack surface for the first time, then watch BlastShield close it.

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How Do I Protect All My OT Devices — Whether I Know What They Are or Not?

15–30%

27%

100%

What is BlastShield?