Hackers and state-sponsored actors constantly probe for weaknesses, aiming to steal or manipulate sensitive data found in Government or Defense institutions.
When even a single breach could destabilize systems, sensitive intelligence becomes either a key asset, or a devastating weapon.
But security isn’t one-size-fits-all, so how do we protect this data?
As threats evolve, so must our defenses.
We have to build systems that can integrate, scale, and fit the unique needs of each entity.
CDS (Cross-Domain Solutions) are such a system; and they may become complex to ensure protection of the relevant environments.
High Stakes Demand Flexibility and Resilience
A Cross-domain Solution is the mechanism used to secure critical data and enable communication between different levels of classified environments.
These systems usually range from the lower classification tier (unrestricted data) to the most sensitive intelligence (top secret). A key function of cross-domain is to protect the hosting environment, application and data stores associated with the higher classification.
Not forgetting a CDS is also there to ensure accountability for the individual who decides to move the data out of the higher classification.
Within the CDS, a set of SEFs (Security Enforcing Functions) needs to be selected to meet the particular cross-domain situation being addressed.
Even the simplest CDS may have multiple components.
How Cross-domain Protects Government & Defense Institutions
With the potential impact of sensitive data being compromised, a CDS adds a vital level of security to protecting the integrity of operations and the safety of national assets.
Import & Export Risks
It’s always risky to move data around, but in government and defense sectors, the risk is amplified by the advanced capabilities threat actors may employ to exfiltrate or corrupt sensitive information.
If we fail to securely manage data transfers, sensitive information can be leaked, and we may unknowingly give unauthorized individuals access to sensitive environments.
In all these scenarios, the consequences could cripple operations, endanger personnel, or compromise national security.
Regulations in Government and Defense
National technical authorities have recognized architectural patterns and outcomes that guide Government and Defense when designing and implementing cross-domain solutions.
For example, the United Kingdom have two patterns for moving data, defined by the National Cyber Security Centre (NSCS):
- Safely Importing Data
- Safely Exporting Data
The emphasis is a little different for the import and the export of data.
Import is concerned with the protection of the high side (higher tier) environment, ensuring good data hygiene, including detection of Zero-Day attacks.
The export of data has a focus on the correct release of information from a higher to lower domain.
A CDS built to protect UK institutions should follow these patterns, which can be readily supported by a more modular cybersecurity architecture.
The UK isn’t the only region with such patterns in effect.
The United States’ National Cross-domain Strategy & Management Office developed its own standards and guidance documents regarding CDS architecture, as has NATO
While these patterns differ to some degree, they do share similarities with other countries and regional CDS patterns.
In such a highly regulated environment, data hosting organizations need to build a system which offers the necessary resilience, auditability, and scalability needed by a functioning CDS.
For such a system, a combination of modular software and hardware components allows a more tailored approach, meeting design pattern guidance, and allowing functional expansion and adaptation as the set of cross-domain needs to increase.
Why is Cross-domain a Challenge?
Even if the CDS relies on predefined patterns, designing the system isn’t straightforward.
In the past, CDS could just mean two communities of interest (COIs) exchanging a limited set of data between two classifications.
A more hardware-centric, static solution was naturally more suited.
Accrediting a solution in this circumstance can be seen as an easier task than a more complex CDS.
As simple as this sounds, it can lead to a proliferation of small, stove-piped solutions that cannot be aggregated and become problematic to manage.
Today, the COIs are more diverse, the required data types for transfer have massively expanded, and the platforms for low and high side hosting have taken advantage of cloud-based technologies.
Combined with threat evolution, designing a CDS with longevity requires a more modular and orchestrated approach.
Increased Data Types and Volumes
Data required by Government and Defense organizations comes in many types and can be from a myriad of sources.
Some of this data will be standard user-based workloads such as office-based productivity files. Other types will be system-based workloads such as system updates or code-based files, while some will be geospatial, command & control and may include more proprietary formats.
Cross-domain solutions should be capable of securely handling any range of formats, often bilaterally, as well as the flexibility to add new types when the need arises. Volumes may also change - more limited, static solutions may have well scoped and understood volumes, but larger, more dynamic solutions can have considerable variance.
Scalability becomes key in these environments, whereby a solution lends itself to a blend of secure but scalable software plus hardware, to achieve the necessary SEFs but in an expandable fashion.
Emerging Threats
Nation-state actors will always seek to acquire or disrupt sensitive data.
They will target the data itself, the data storage, or the consuming applications.
The more sensitive the data, the greater the security impact, be it personal, national, or regional, leading to compromise of people, assets and commerce.
While traditional security measures within classified environments may prevent some breaches, the movement of data between different security levels creates vulnerabilities. This provides threat actors with an opportunity to disrupt that data.
Ensuring the integrity of the data (not just its confidentiality) is paramount. Obfuscation (encryption) is not the same as ‘correct’, and this requirement for ‘correct content’ is a key purpose of a CDS.
Lower classification environments are often more susceptible to malware infections and data manipulation attempts, so it's essential to ensure data hygiene when data traverses between classifications.
As data moves across trust boundaries, a CDS must invoke functions to ensure the hygiene of data, preventing any compromise of the higher classification environment and data sets.
New Operational Models
Permanently isolating data is rarely effective when seamless, cross-territorial collaboration is required.
The business need for analysis and aggregation of data requires government and defense entities to import and export data between different trust levels.
In this context, CDS should adapt not only to rapidly evolving threats, but also to rapidly evolving operational models.
OPSWAT’s Solution to Cross Domain Challenges
A fully functional CDS must act as a mediator, balancing the operational need for data access with the ability to perform data content checks along with other SEFs, quickly and automatically.
With its highly configurable components, centered around MetaDefender Core, that can be deployed on a range of hosting environments, OPSWAT allows you to build a modular cross-domain architecture.
You can tailor your SEFs from the range of options provided by OPSWAT, ensuring you can protect your data without compromise.
The OPSWAT portfolio provides a range of SEFs that can be layered to increase data protection depending on the data and environment sensitivity.
OPSWAT’s patented Metascan™ Multiscanning and Deep CDR™ technologies will scan data for known threats and remove malware complementary to other data verification techniques deployed.
In the case of more sensitive files, the emulation-based Adaptive Sandbox assesses files in a controlled environment, letting you observe their behavior, without releasing malware into the environment.
To add an additional context level to your decision, OPSWAT can also deliver Threat Intelligence capabilities, truly shining a light on the data you’re importing. With OPSWAT, you can get insights on the Country of Origin, file IoC, and vulnerabilities.
Data Ingest
Inputting and extracting data into a cross-domain solution is often overlooked.
MetaDefender Storage Security (MDSS) and MetaDefender Managed File Transfer (MFT), are among OPSWATS connector and API techniques, encompassing standard storage and leveraging MetaDefender Core and SEFs to flow data through a range of security controls.
Media import is also accommodated by our MetaDefender Kiosk product, protecting your critical network and assets against peripheral and removable media threats. It scans +13,000 files per minute, so data volume isn’t a problem.
Content Filtering
Content filtering involves syntactic and semantic verification, as well as CDR techniques.
Syntactic and semantic checks work best when data is simplified into an easily examinable form—a process called Transformation. Filtering is most effective on user-based workloads that can be transformed.
While CDS must handle both user- and system-based workloads, different security-enforcing functions (SEFs) need to be combined to properly clean each type. This can be easily configured and managed using MetaDefender Core.
Context, Not Verdicts
OPSWAT’s solutions come into the cybersecurity landscape with an added layer of data intel.
These solutions aren’t built on prevention and protection alone. They provide the context needed for better long-term decision making.
There’s threat intelligence delivered through country-of-origin investigations, vulnerability scans, and supply chain insights.
Don’t Replace; Enhance
Replacing CDS can be an expensive and frustrating activity.
OPSWAT’s software-driven approach makes it easy to enhance solutions by adding extra security layers around existing features.
The MetaDefender Platform allows you to plug-in or plug-out products, according to what you need. The architecture isn’t set in stone; it’s as fluid and adaptable as the CDS needs to be. MetaDefender Core is your hardware-agnostic partner, with the scalability and the ability to build tailored solutions.
OPSWAT’s highly configurable components can be deployed on a range of hosting options, allowing scalability when data types and volumes change.The Netwall family of diodes integrates seamlessly with MetaDefender products and also works with a variety of cross-domain hardware to expand current capabilities.
Connect with an expert today to discover how OPSWAT can give you the critical and tactical advantage when it comes to cross-domain security.
FAQs
What is a CDS (cross-domain solution)?
A cross-domain solution or CDS is the mechanism used to secure critical data and enable communication between domains, systems, or networks that are separated by security classifications and/or trust levels.
What is a cross-domain solution used for?
CDSs are used by Government and Defense institutions to securely transfer sensitive or classified information between security domains while maintaining strict policy enforcement and preventing unauthorized access or data leakage.
How do cross-domain solutions work?
CDSs employ hardware and software components—such as filters, data guards, and data diodes—to transform, inspect and securely transmit data across different domains.
Why are cross-domain solutions important?
Cross-domain solutions are crucial to facilitating the operational need for data sharing while maintaining security in sensitive environments.
What are the potential risks and challenges associated with CDS?
CDS challenges include integration with legacy systems, increased data volumes, new operational models, managing latency and evolving threats.
What are the core components of a cross-domain solution?
Core components include controlled interfaces, content filtering mechanisms, unidirectional control and protocol breaking, and optionally, AV scanning.
All components should provide logging output, allowing a transaction to be traced end to end; and secondary functions consumed by a CDSs may include access control, data encryption, auditing, data transformation, and secure protocols. Hosting functions should be secured and maintained.
What is a high assurance guard in a CDS?
A high assurance guard is a security appliance that has been securely designed, is a standalone device and enforces a range of SEFs, including unidirectional control, protocol breaks and a certain level of content filtering. Additional software components, most likely data scanning and content filtering if required, will need to be integrated with a guard to provide fuller functionality.
What is a controlled interface in a CDS?
A controlled interface regulates data communication between different security domains, ensuring that content complies with policies and cannot be tampered with or misused during transfer.
What is content filtering in a CDS?
Content filtering involves scanning, validating, and sanitizing data to prevent malicious code, sensitive information leaks, or non-compliant content from crossing domains.
What are Security Enforcing Functions (SEFs) in a CDS?
A SEF is a specific function that is needed, usually as part of a chain of SEFs, that contributes to ensuring inbound or outbound data traversing a CDS is 'clean' according to its specific purpose. For example, content filtering SEF will undertake a deep inspection of data, ensuring certain structural and/or semantic criteria are met.
What is the difference between bidirectional and unidirectional data flows?
Unidirectional flows—enforced by devices like data or optical diodes—only permit one-way transfer, offering stronger isolation and security.
Unidirectional flows are either lower classification to higher classification, or higher classification to lower classification. The chain of SEFs to enact the flow are discreet and their functionality is not usually shared with other functions in the environment. An import flow can have a different emphasis (in terms of SEFs) than an export flow.
Bidirectional flows consist of discreet import and export flows.
How do CDSs integrate with existing network infrastructure?
A CDS is designed for compatibility with existing systems, particularly on the low side (the lower classification environment), where it may be in a segmented section of an Enterprise environment. The high side (higher classification) can often be air gapped and/or highly segmented, often requiring different support functions and integration with the low side of a CDS.
What are the main approaches to implementing a CDS?
CDSs can be implemented using hardware only or a hybrid solution including hardware and software, depending on the organization’s risk appetite, scalability and latency requirements.
What’s the difference between hardware-based and software-based CDSs?
Hardware-based CDSs offer greater isolation and tamper resistance, often using purpose-built appliances. Software-based CDSs provide more adaptability, allowing virtual or cloud deployment models with broader scalability.
What are the deployment models for CDSs?
The two primary models are fixed CDSs for permanent installations in fixed locations, and tactical CDSs designed for mobility, ruggedization, and temporary mission environments.
How do CDSs support air-gapped networks?
CDSs enable secure file and data transfer between isolated, air-gapped systems by using controlled devices (e.g., data diodes) and removable media that are scanned and filtered before transfers.
In which industries are cross-domain solutions used?
CDSs are mainly created for Government and Defense industries. However, some CDS components are integrated in energy, utilities, healthcare, finance, telecommunications, and aviation—anywhere secure communication across trust levels is required.
How do CDSs enable secure information sharing in government and defense?
CDSs facilitate real-time intelligence sharing and operational coordination between classified and unclassified systems, supporting inter-agency collaboration, national security, and regulatory compliance.
What are some operational application examples of CDSs?
CDSs are used for transferring satellite intelligence from classified to unclassified networks, enabling coalition mission coordination, and securely exchanging data during operational scenarios.
What are the benefits of using a CDS?
Key benefits include enhanced security, reduced insider threat, compliance with regulations, seamless data interoperability, real-time collaboration, and improved decision-making.
How do CDSs reduce insider threat risks?
CDSs enforce strict access controls, data filtering, and audit logging that prevent unauthorized data movement—even from trusted users—mitigating insider threats and improving visibility.
Are CDSs compliant with cybersecurity regulations?
Yes, CDSs are designed to align with cybersecurity frameworks and standards such as NIST RMF, GDPR, HIPAA, and DoD Raise the Bar. They help organizations enforce secure, policy-compliant data exchanges.
What is the Raise the Bar initiative?
It is a U.S. government initiative to improve the security and effectiveness of CDS by setting stricter standards and certification requirements for vendors and technologies.
