Snowflake data masking: Risks and best practices

Key takeaways 

• Snowflake data masking relies on dynamic, role-based masking at query time, which is useful for access control but limited for compliance-grade protection.

• Dynamic masking leaves production data unchanged, increasing exposure risk if credentials or environments are compromised, as shown in recent Snowflake customer breaches.

• Static data masking permanently replaces sensitive data with realistic values while preserving referential integrity.

• Static masking can be applied in-flight or after data is loaded into Snowflake, each with tradeoffs.

• K2view supports both approaches using an entity-based model designed for enterprise Snowflake environments.

What is data masking in Snowflake 

Snowflake data masking is a dynamic masking capability that protects sensitive data by substituting real values with synthetic but realistic values at query time, and leaving the underlying data stored in Snowflake unchanged.  

At a high level:  

• Snowflake admins define masking policies on columns that hold sensitive data 

• Snowflake evaluates user roles when a query runs 

• Users with the required privileges see the original, unmasked values, and all others receive masked data. 

This approach is effective for access and visibility control, but it does not physically protect sensitive data stored in Snowflake. 

Core use cases for Snowflake dynamic data masking 

Snowflake dynamic data masking is commonly used when multiple teams query the same datasets but require different visibility into sensitive values. Here are a few examples: 

Financial services 

• Data analysts: work with synthetic substitutes for customer PII and financial attributes. 

• Senior finance staff: may access primary account numbers (PANs) and customer details. 

• Contact center agents: see partial values for PII, such as the last four digits of a PAN. 

Healthcare 

• Clinicians: access original patient identifiers when needed for care delivery. 

• Analytics teams: use synthetic substitutes and redacted fields for PHI for reporting and planning. 

• Auditors and contractors: receive restricted views based on scope and approvals. 

Retail and consumer goods 

• Internal analytics: use synthetic substitutes for customer identifiers while retaining behavioral data. 

• Suppliers and partners: access aggregated data with customer identities removed or substituted. 

Technology and SaaS 

• HR and payroll: access original employee identifiers and compensation data. 

• Analytics teams: work with redacted employee data. 

• Managers: view aggregated or partially revealed information. 

The pitfalls of Snowflake dynamic data masking 

Snowflake’s native data masking capabilities have important limitations when used as the primary data protection mechanism. 

Production data remains intact  

Although Snowflake itself was not breached at the platform level, large-scale credential-based attacks led to widespread exposure of sensitive data stored in Snowflake customer environments. The attacks enabled threat actors to access unmasked production data that remained fully intact in Snowflake. 

Notable reported incidents include: 

• Ticketmaster customer data breach via Snowflake 

  Ticketmaster disclosed that attackers accessed a Snowflake-hosted database containing customer information, including names, email addresses, phone numbers, and partial payment data. 

• AT&T confirms Snowflake-related data exposure 

  AT&T confirmed that customer data was illegally downloaded from a Snowflake environment, affecting millions of records and resulting in regulatory scrutiny and legal action. 

• Santander Bank impacted in Snowflake credential attack campaign 

  Santander reported unauthorized access to employee data as part of the broader Snowflake credential-theft campaign affecting multiple global enterprises. 

These incidents highlight that dynamic data masking alone cannot prevent data exposure when credentials, sessions, or environments are compromised.  When production data remains unmasked, attackers who gain access to Snowflake can retrieve a company’s sensitive data at scale.  

Additional Snowflake data masking limitations 

• Policy complexity at scale 

  Managing role-based masking policies across schemas, environments, and teams quickly becomes operationally complex. 

• Query performance overhead 

  Masking logic is applied at query time, which can impact performance for complex analytical workloads.

• Limited masking depth 

  Snowflake supports basic masking functions but lacks advanced techniques needed for strict regulatory or enterprise use cases. 

Why stronger Snowflake data masking is a compliance priority 

The need for stronger data masking in Snowflake is driven by rising breach frequency, expanding cloud exposure, and increasing regulatory pressure. 

• Data breaches are increasing in scale and frequency 

  In Q1 2025 alone, 658 distinct data breaches were reported, impacting more than 32 million individuals. 

• The financial impact of breaches continues to rise. 

  The average global cost of a data breach reached $4.44 million, while U.S.-based breaches averaged $10.22 million. 

• Customer PII and cloud data are the primary targets 

  Research shows that 46% of breaches involve customer PII, and 82% involve cloud-stored data, highlighting the exposure risk for cloud platforms like Snowflake. 

• Stolen credentials remain a leading attack vector 

  Credential theft and misconfigurations continue to be among the most common causes of cloud data exposure, the same pattern observed in Snowflake customer environments. 

• Snowflake customer environments directly impacted 

  During the 2024 credential compromise campaign, approximately 165 Snowflake customer accounts were affected. 

• Regulatory and consumer pressure continues to grow. 

  Surveys show that 85% of adults want stronger protections for their personal data, increasing pressure on organizations to enforce privacy in analytics platforms. 

Static data masking for Snowflake: the ideal solution 

Static data masking permanently replaces sensitive data with realistic, fictitious values while maintaining referential integrity across tables. This approach significantly reduces exposure risk and enables compliant data use for analytics, testing, and data sharing. 

Compared to dynamic masking, Snowflake static masking: 

• Secures Snowflake data at rest, not just at query time 

• Supports downstream environments such as dev and QA 

• Enables safer data replication and sharing 

• Aligns better with GDPR, CCPA, and HIPAA requirements 

Two approaches to static data masking in Snowflake 

There are two common architectural approaches to implementing static data masking for Snowflake, each with distinct tradeoffs in security, complexity, and cost. 

How K2view enhances Snowflake data masking 

K2view Enterprise Data Masking supports both static data masking approaches for Snowflake, using an entity-based data model.  

K2view’s in-flight masking ingests data from multiple source systems by business entity, applies consistent masking to each entity in real time, and then loads the masked data into Snowflake. Masking after load, by contrast, applies consistent masking across all Snowflake tables that store data for the same business entity. 

Key advantages include: 

• Referential integrity preserved across Snowflake and external sources 

• Consistent masking across entities, not just tables 

• Centralized governance without role explosion 

• Enterprise-grade scalability for regulated environments 

• K2view’s in-flight approach avoids orphaned records that can compromise analytics accuracy. 

Experience enterprise data masking for Snowflake 

See how K2view delivers static, compliance-ready Snowflake data masking at scale. Take the live product tour and experience enterprise data masking designed for modern analytics and regulatory demands.