In today’s era of Big Data, machine learning (ML) systems are increasingly becoming the custodians of vast quantities of sensitive information. As ML algorithms learn from data, they inevitably come in contact with personal, financial, and even classified information. While these systems promise revolutionary advancements in various sectors, they also introduce unprecedented challenges in cybersecurity. One primary concern is handling and protecting this sensitive data throughout the ML workflow. Among the myriad of available solutions, data masking, and more specifically, Dynamic Data Masking (DDM), is emerging as a crucial tool for enhancing security protocols. The technique protects sensitive data and allows ML systems to operate without compromising the integrity of the information.

What is Data Masking?

Data masking, also known as data obfuscation or data anonymization, serves as a crucial technique for ensuring data confidentiality and integrity, particularly in non-production environments like development, testing, and analytics. It operates by replacing actual sensitive data with a sanitized version, rendering the data ineffective for malicious exploitation while retaining its functional utility for testing or analysis.

Underlying Algorithms and Techniques

Technically, data masking is often implemented through deterministic or probabilistic algorithms. In a deterministic masking algorithm, a given input will always produce the same masked output. This is valuable in instances where data relationships need to be maintained across multiple datasets. On the other hand, probabilistic algorithms generate varied outputs, even for the same input, offering an additional layer of security but potentially complicating data analytics tasks that depend on consistent relationships.

Preserving Data Format

Another technical facet of data masking is format-preserving encryption (FPE), a technique that replaces each data entry in a way that the output retains the structural format of the input. This is especially useful in situations like database testing, where the format of the data is integral to the functionality of the system being tested.

Masking Granularity

From a technical standpoint, data masking can be implemented at different granularities, either at the column-level or field level. Column-level masking involves replacing an entire column of data, which is usually beneficial when an entire dataset is considered sensitive. Field-level masking, however, targets specific data fields, offering a more nuanced approach that allows certain portions of the data to be visible while masking others.

Tokenization vs Masking

It’s also important to distinguish between data masking and tokenization. While both aim to protect data, tokenization replaces sensitive data with a random token and usually involves a separate database that maps tokens back to the actual data. Data masking, however, doesn’t require such back-mapping, making it a one-way operation that further enhances security.

By applying these technical principles, data masking stands as a robust security measure, especially within machine learning workflows where data often flows between different phases and environments, thus requiring vigilant protective measures to maintain its integrity and confidentiality.

Why Data Masking is Indispensable in Modern Data Management

Regulatory Compliance and Data Masking Algorithms

Adherence to legal frameworks such as GDPR in the European Union or CCPA in the United States is a non-negotiable aspect of modern data management. Compliance often requires auditable methods to secure personally identifiable information (PII) or sensitive personal data (SPD). Data masking offers algorithmic solutions that can be formally reviewed, enabling organizations to meet complex compliance requirements. These algorithms also support pseudo-anonymization, a GDPR-compliant method where the data can still be mapped back to its source without revealing the actual data.

Risk Mitigation in Data Breaches

Data breaches are not only detrimental to an organization’s reputation but can also impose significant financial costs. Utilizing advanced data masking techniques, such as conditional masking based on access levels or dynamic masking that only reveals data when specific conditions are met, can provide an extra layer of security. These methods ensure that even if a data breach occurs, the exposed data remains non-exploitable, thus reducing the overall impact of the breach.

Intellectual Property Protection Through Secure Masking Techniques

For organizations where data is integral to intellectual property, such as machine learning models or proprietary algorithms, standard encryption may not suffice. Data masking techniques that involve the use of format-preserving encryption (FPE) can help in maintaining the data structure while ensuring that the data itself is unintelligible. This is paramount for organizations looking to run analytics or tests without jeopardizing their proprietary methods.

Public Trust and Cryptographic Assurance

With the increasing public scrutiny of data management practices, maintaining trust requires more than just compliance. Cryptographically secure data masking techniques offer a mathematical guarantee of security, unlike simple obfuscation methods. By employing secure algorithms for data masking, organizations can substantiate their claims of data security, thus enhancing their reputation in an increasingly privacy-aware market.

Operational Efficiency and Performance Metrics

Efficiency is a critical factor in data operations. Masking techniques can be resource-intensive, and therefore, it’s imperative to choose a method that minimizes computational overhead. Advances in data masking technology, such as partitioned masking or streaming masking, enable real-time or near-real-time data protection with less impact on system performance.

Data Masking in Multi-Cloud and Hybrid Environments

Data often resides across multiple platforms and geographical locations, creating challenges for consistent data masking. Emerging techniques are increasingly cloud-agnostic and support APIs for smooth integration into complex data workflows. This allows organizations to implement uniform data masking standards across various environments, including multi-cloud and hybrid setups.

Dynamic Data Masking in Modern Data Environments

Dynamic Data Masking (DDM) is a real-time data protection mechanism that essentially acts as a security facade in front of your actual data. It shields sensitive information from unauthorized access by obfuscating, or masking, the data in transit, right at the moment a query is made. Unlike Static Data Masking, which alters the data at rest in a database, DDM leaves the original data untouched, implementing masking rules dynamically. DDM offers a robust, agile, and scalable solution to data privacy challenges, especially in real-time, data-intensive environments. It is increasingly becoming an essential component of comprehensive cybersecurity strategies, especially in sectors with elevated data sensitivity and regulatory compliance mandates, such as healthcarefinance, and governmental services. Below, we unpack the underlying technology and key capabilities that make DDM a revolutionary tool in data protection.

Real-Time Masking Engine and Query Interception

One of the most compelling features of DDM is its real-time capabilities. Unlike traditional static data masking techniques, which modify the data at rest, DDM operates through a real-time masking engine that intercepts database queries. This interception layer dynamically modifies the SQL queries to implement masking rules before the data is sent to the requester. This is accomplished without altering the actual data stored in the database, which remains in its original, sensitive form.

Fine-Grained Access Control through Policy Rules

DDM’s flexibility lies in its policy rule engine, allowing for fine-grained control over who sees what data. For instance, you can implement role-based masking rules or conditional rules based on query parameters. This enables a tailored masking strategy that can adapt dynamically to the authorization levels and specific needs of different users or systems interacting with the data.

Algorithmic Versatility in Masking Methods

The masking methods in DDM can range from simple techniques, like redacting specific characters from a string to complex techniques involving format-preserving encryption or hashing. Organizations can choose the algorithmic complexity based on their specific needs for computational speed and data security. The architecture allows for plug-and-play algorithmic modules, making it easy to upgrade or change the masking algorithm without modifying the underlying database or applications.

High Availability and Scalability Concerns

DDM solutions often come with built-in features for high availability and scalability. The masking process can be distributed across multiple servers or operate in a cloud environment, ensuring that the real-time capabilities of DDM do not become a bottleneck in high-throughput data pipelines. Redundant masking nodes can be employed to provide fail-over capabilities, ensuring continuous data availability.

Data Lineage and Auditing Capabilities

Maintaining a record of who accessed what data is crucial for both compliance and security. DDM solutions generally integrate well with existing logging and auditing frameworks. They can provide detailed metadata about the masking operations, including what data was accessed, by whom, and what masking rule was applied. This creates a strong audit trail, which is crucial for regulatory compliance and forensic analysis.

Dynamic Data Masking in Multi-Tenant Environments

In a multi-tenant architecture, where a single database may serve multiple clients, DDM offers the capability to enforce data masking rules based on tenant-specific policies. This is particularly useful for SaaS applications that need to ensure data isolation between tenants while still leveraging a shared infrastructure.

Dynamic Data Masking in Recent Research

Recent academic research has substantially contributed to the evolving landscape of data masking, solidifying its critical role across various sectors. A study highlighted the indispensability of data masking for GDPR compliance in healthcare, a sector rife with sensitive and often targeted patient data. This work has become a touchstone for healthcare providers striving to marry compliance with quality patient care. Closely following this, a study offered a comprehensive guide to the real-world application of dynamic data masking in financial transactions, making it an invaluable resource for financial institutions that grapple with a large volume of sensitive data. Complementing this, extensive research performed a comparative analysis of static and dynamic data masking techniques, offering businesses a much-needed guide to choosing the right method tailored to their unique security requirements. Amidst the backdrop of increasing cloud adoption, a seminal work elucidates the ways data masking can preserve data privacy in cloud storage solutions. Concurrently, research made a notable expansion of the data masking for audio genre discourse into the realm of big data analytics. They showcased how dynamic data masking is not only efficient but also exceptionally effective in securing large-scale datasets. The study introduced a frontier discussion of dynamic data masking within the burgeoning Internet of Things. Moreover, a study in Artificial Intelligence Research clarified the often-debated issue of data masking’s applicability in machine learning models, proving it can secure data without hampering the model’s performance. Collectively, these studies form both a validation and a directive for organizations, emphasizing the ever-growing importance and adaptability of data masking in contemporary data security and privacy scenarios.

Best Practices for Implementing Dynamic Data Masking

Needs Assessment: Prioritize the data that requires masking based on sensitivity and regulatory requirements.

Role-Based Access: Customize masking rules depending on the user’s roles. For instance, an HR person may see the full names and partial social security numbers, while a third-party contractor may see only masked data.

Monitoring and Auditing: Keep a log of who accessed the data and what was viewed, to ensure compliance and to monitor any unauthorized access attempts.

Regular Updates: Technology and compliance requirements are ever-changing. Update your data masking strategies periodically to adapt to new challenges.


In a world swamped with data and riddled with security risks, data masking has emerged as a critical defensive tool. Focusing specifically on Dynamic Data Masking, it is evident that the technique offers a harmonious blend of security and functionality, making it increasingly relevant in today’s complex data environments. Given its extensive research backing and its adaptability to emerging data privacy challenges, data masking is no longer an optional exercise but an essential practice for any organization that takes data privacy and security seriously.

By implementing rigorous data masking techniques like Dynamic Data Masking, organizations can safeguard sensitive information, comply with privacy laws, and foster customer trust, all while deriving the analytical benefits that data offers.


  1. Surridge, M., Meacham, K., Papay, J., Phillips, S. C., Pickering, J. B., Shafiee, A., & Wilkinson, T. (2019). Modelling compliance threats and security analysis of cross border health data exchange. In New Trends in Model and Data Engineering: MEDI 2019 International Workshops, DETECT, DSSGA, TRIDENT, Toulouse, France, October 28–31, 2019, Proceedings 9 (pp. 180-189). Springer International Publishing.
  2. Verykios, V. S., Stavropoulos, E. C., Zorkadis, V., Katsikatsos, G., & Sakkopoulos, E. (2022). Sensitive data hiding in financial anti-fraud process. International Journal of Electronic Governance14(1-2), 7-27.
  3. Jain, R. B., Puri, M., & Jain, U. (2018). A robust dynamic data masking transformation approach to safeguard sensitive data. Int. J. Future Revolution Comput. Sci. Commun. Eng4(2).
  4. Enireddy, V., Somasundaram, K., Prabhu, M. R., & Babu, D. V. (2021, October). Data obfuscation technique in cloud security. In 2021 2nd International Conference on Smart Electronics and Communication (ICOSEC) (pp. 358-362). IEEE.
  5. Ahmad, T., & Samudra, Y. (2020). Reversible data hiding with segmented secrets and smoothed samples in various audio genres. Journal of Big Data7(1), 1-19.
  6. Anand, A., & Singh, A. K. (2022). A hybrid optimization-based medical data hiding scheme for industrial internet of things security. IEEE Transactions on Industrial Informatics19(1), 1051-1058.
  7. Hey, T., Butler, K., Jackson, S., & Thiyagalingam, J. (2020). Machine learning and big scientific data. Philosophical Transactions of the Royal Society A378(2166), 20190054.
Avatar of Marin Ivezic
Marin Ivezic
Website | Other articles

For over 30 years, Marin Ivezic has been protecting critical infrastructure and financial services against cyber, financial crime and regulatory risks posed by complex and emerging technologies.

He held multiple interim CISO and technology leadership roles in Global 2000 companies.