Split Knowledge and Dual Control: Safeguarding Your Payment Card Data

When considering payment card security, protecting sensitive data is critical. This requires a multi-layered approach to ensuring that data is encrypted at rest and in transit. How you manage your encryption keys is critically important. An often overlooked aspect of cryptographic key management is the process of exchanging encryption keys. This blog post delves into the significance of key management, and provides an overview of the procedural, technical, and operational controls necessary for PCI compliance as required in PCI DSS Requirement 3.6.6.

Introduction to Split Knowledge and Dual Control

Split Knowledge and Dual Control are fundamental security principles that, when applied to key management, play a crucial role in protecting sensitive payment card information. They ensure that no single individual has unilateral control over sensitive operations or access to encrypted data. But how do they work, and why are they so important?

PCI DSS Requirement 3.6.6: In the case of manual open text
encryption key management operations, these operations
should be managed using split knowledge and dual control.
PCI DSS Guide https://pcidssguide.com/pci-dss-requirement-3/

What is Split Knowledge?

Split knowledge refers to a scenario where the information or capability needed to perform a sensitive task, such as decrypting data, is divided among multiple individuals. This means that one person alone cannot access or reveal sensitive information without the cooperation of at least one other authorized person.

What is Dual Control?

Dual Control is a complementary principle that requires two or more authorized individuals to jointly perform certain operations or access sensitive information. This collaboration is crucial for executing tasks such as the activation, generation, or modification of cryptographic keys.

The Importance in Key Management and Exchange

In the realm of PCI DSS compliance, managing and exchanging encryption keys with these principles in mind is not just a recommendation—it’s a requirement. The encryption keys that safeguard payment card data must be handled with utmost care, and both split knowledge and dual control are central to achieving this goal.

Key Exchange with Split Knowledge and Dual Control

The process of exchanging encryption keys between parties, such as merchants and payment terminal vendors, must be conducted securely. Employing split knowledge and dual control ensures that the keys are not compromised during exchange and that they are handled securely at all stages of their lifecycle.

Implementing Split Knowledge and Dual Control for PCI Compliance

Achieving compliance involves a multifaceted approach that includes procedural, technical, and operational controls. Let’s explore these controls and how they contribute to secure key management practices.

Procedural Controls

Procedural controls are about defining and documenting the policies and procedures that govern how encryption keys are managed. This includes:

Establishing Policies: Define clear policies that outline how keys should be handled, who has access, and under what circumstances.
Training Personnel: Ensure that all personnel involved in key management are trained on the policies and understand their responsibilities.
Regular Audits: Conduct regular audits to ensure compliance with the policies and to identify and rectify any lapses in security.

Technical Controls

Technical controls involve the use of technology to enforce the principles of split knowledge and dual control. This includes:

Secure Key Storage: Employ secure storage solutions for keys that support split knowledge and dual control mechanisms.
Encryption of Keys during Transmission: Ensure that keys are encrypted when being transmitted between parties, to prevent interception and unauthorized access.
Access Controls: Implement robust access controls that require multiple authorized users to perform sensitive operations with keys.

Operational Controls

Operational controls focus on the day-to-day management and operation of key management practices. This includes:

Key Generation and Activation: Ensure that key generation and activation processes require the participation of multiple authorized individuals.
Key Rotation and Replacement: Regularly rotate and replace keys, adhering to procedures that enforce split knowledge and dual control.
Incident Response Plans: Have plans in place to respond to security incidents involving keys, ensuring that the response requires collaborative efforts from multiple team members.

The Benefits of Implementing These Controls

The implementation of split knowledge and dual control, along with the associated controls, offers numerous benefits:

Enhanced Security: By requiring collaboration among multiple individuals, the risk of unauthorized access or misuse of encryption keys is significantly reduced.
Compliance: Adherence to these principles is essential for PCI DSS compliance, helping to avoid potential fines and reputational damage.
Improved Trust: Demonstrating a commitment to these security principles can improve trust among customers and partners.

The Importance of Using Automated Processes

Implementing automated processes that enforce split knowledge and dual control principles is crucial for enhancing security, efficiency, and compliance within any organization that handles sensitive data, especially in environments regulated by PCI DSS. Automation plays a pivotal role in ensuring these principles are consistently applied without relying solely on manual intervention, which can be prone to human error or deliberate misuse. Here’s why the automation of these processes is so important:

Enhanced Security

Automated processes reduce the risk of human error, one of the primary threats to data security. By automating the enforcement of split knowledge and dual control, organizations can ensure that sensitive operations, like key management or access to encrypted data, require actions or approvals from multiple authorized individuals without the possibility of bypassing these requirements through oversight or misconduct.

Consistent Compliance

PCI DSS emphasizes the importance of split knowledge and dual control to protect sensitive information and is explicitly covered in Requirement 3.6. Automated processes help ensure that these principles are not only implemented but also consistently enforced across all relevant operations, aiding in continuous compliance. Automation provides a clear, auditable trail of compliance efforts, making it easier to demonstrate adherence to regulatory requirements during audits.

Operational Efficiency

While the principles of split knowledge and dual control are essential for security, manually implementing these can be time-consuming and labor-intensive, potentially slowing down critical operations. Automation streamlines these processes, enabling quick and efficient execution of tasks that require multiple approvals or actions. This efficiency ensures that security measures do not impede business operations, providing a balance between security and operational agility.

Scalability

As organizations grow, the volume of sensitive operations that require split knowledge and dual control can increase significantly. Automation allows these principles to be scaled efficiently, ensuring that security and compliance measures grow with the organization without requiring a linear increase in manual oversight or administrative burden.

Reduced Insider Threat

One of the primary goals of split knowledge and dual control is to mitigate the risk posed by insider threats. Automated processes ensure that no single individual has the ability to perform sensitive operations unilaterally, significantly reducing the potential for insider misuse or theft. Automation ensures that checks and balances are in place, even if an individual with malicious intent attempts to bypass security protocols.

Real-time Monitoring and Alerting

Automated systems can provide real-time monitoring and alerting for operations that require split knowledge and dual control, ensuring that any unauthorized attempts to access sensitive information or perform unauthorized operations are detected and addressed immediately. This capability enhances the organization’s security posture by providing timely responses to potential security incidents.

Implementation Considerations

To effectively implement automated processes for split knowledge and dual control, organizations should consider the following:

Integration with Existing Systems: Automated processes should seamlessly integrate with existing security and operational systems to ensure comprehensive coverage without creating new vulnerabilities.
Customization and Flexibility: Automation tools should offer customization options to accommodate the specific requirements and workflows of the organization, allowing for the effective implementation of split knowledge and dual control principles.
User Training and Awareness: While automation can significantly reduce the risk of human error, the importance of user training and awareness cannot be overstated. Personnel should be educated on the importance of these security principles and how automated processes support them.

Using Azure Payments HSM or Azure Key Vault HSM

See A Comparison of Azure Payment HSM and Azure Key Vault HSM for more information on these two services.

Azure Payments HSM and Azure Key Vault HSM are cloud services provided by Microsoft that allows users to securely store and access secrets, keys, and certificates. They are vital tools for organizations looking to manage their cryptographic keys and secrets efficiently and securely, especially when complying with standards like PCI DSS. Implementing the principles of split knowledge and dual control in these services involves leveraging their features to ensure that no single individual has complete control over cryptographic keys, secrets, or certificate management processes. Here’s how these principles can be effectively implemented using these services:

Role-Based Access Control (RBAC)

Integration with Microsoft Entra ID provides role-based access control. You can assign specific roles to users or groups, controlling who can manage and who can only view or use the keys, secrets, or certificates. Implementing split knowledge and dual control can begin with assigning the appropriate roles to different team members, ensuring that no single person has full access to sensitive operations.

Dual Control: Require approval from multiple authorized individuals before critical roles are assigned or changed, such as those allowing the management of keys or secrets. This is where an effective Change Control Process is an important part of your InfoSec program.

Access Policies

Access policies provide granular permissions to keys, secrets, and certificates. You can specify what operations a user or application can perform, such as key creation, deletion, or decryption operations.

Split Knowledge: Use access policies to divide operational responsibilities among team members. For example, one set of users may have permission to generate keys, while another set may have permission to use those keys for specific operations, ensuring that knowledge and control are split.

Key Import and Generation

You can import your own keys or generate new keys within the HSM. When generating or importing keys:

Dual Control: Ensure that the process of key generation or importation requires actions or approvals from multiple individuals. This can be achieved through internal processes or by using automated workflows that require multiple approvers before a key operation is executed.

Monitoring and Logging

Integration with Azure Monitor and Azure Log Analytics for monitoring and logging is essential for all operations ensuring compliance for auditing purposes.

Operational Integrity: Use logging and monitoring to audit the use and management of keys, verifying that split knowledge and dual control policies are being followed. Regular audits can help identify and correct any deviations from established policies.

Secrets Management

For managing secrets (such as database connection strings or application secrets), you must securely store and tightly control access to tokens, passwords, certificates, API keys, and other secrets.

Split Knowledge: Implement strict access controls on secrets, similar to key management, ensuring that access to sensitive information is divided among multiple individuals or systems, as per your organizational policies.

Conclusion

The implementation of split knowledge and dual control is not just a regulatory requirement; it’s a best practice that can significantly enhance your organization’s security posture. By incorporating these principles into your key management processes, you not only comply with PCI DSS but also build a more resilient and trustworthy system for handling sensitive data. Remember, the goal is not just to protect data but to foster a culture of security that permeates every level of the organization. As you continue to navigate the complexities of PCI compliance, let the principles of split knowledge and dual control guide your approach to data security and protection.

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Split Knowledge and Dual Control: Safeguarding Your Payment Card Data