Implementing strong cryptography is critical to safeguarding cardholder data (CHD) from cybersecurity threats. Adopting robust encryption for CHD based on the tokenization PCI DSS Requirements will help strengthen data security and mitigate threat risks. Read on to learn more.
Breakdown of the Tokenization PCI DSS Requirements
The Payment Card Industry Data Security Standards (PCI DSS) framework stipulates Requirements to help organizations implement secure systems and processes for safeguarding sensitive CHD. Included within the framework are specific tokenization requirements that oversee organizations’ replacement of sensitive CHD with a representative value.
Meeting the tokenization PCI DSS Requirements requires an understanding of:
- The considerations for implementing tokenization PCI DSS solutions
- A breakdown of the PCI DSS tokenization Requirements
- How to design PCI-compliant tokenization systems
Equipped with the appropriate tokenization systems, processes, and tools, you will increase your ROI on cybersecurity and strengthen your overall PCI-sensitive data security.
What is PCI DSS Tokenization?
Per Requirement 3 of the PCI DSS, organizations must secure all forms of CHD storage to prevent incidents of unauthorized exposure. Tokenization PCI DSS Requirements stipulate the use of index tokens to encrypt sensitive elements of CHD, such as primary account numbers (PANs).
Tokenization secures CHD by replacing PANs with meaningless or “surrogate” values, also called tokens. Once tokenized, a previously readable PAN exists as a token with no meaning or value to malicious actors.
Implementing tokenization will help streamline PCI DSS compliance by:
- Reducing the amount of CHD stored within a CHD environment (CDE)
- Minimizing the need to safeguard the storage of sensitive, readable PANs
For some security implementations, tokenization may require much lower safeguards than those necessary for readable PAN storage. Consulting with a PCI compliance advisor will help you determine the best use cases for tokenization PCI DSS solutions.
Considerations for Implementing PCI DSS Tokenization
Compliance with the PCI DSS tokenization guidelines requires organizations to secure sensitive elements of CHD at all times. There are several considerations when choosing to adopt tokenization PCI DSS solutions.
First, tokenization does not replace the need to comply with the PCI DSS Requirements regarding the protection of stored CHD.
Next, CHD tokenization can be augmented by implementing:
- Ongoing validation of tokenization effectiveness to prevent the retrieval of PAN from any system environment, including those outside defined PCI DSS scope
- Adequate monitoring and protection of tokenization solutions
- Evaluation and risk analysis of tokenization implementations across:
- Deployment models
- De-tokenization methods
- Tokenization technologies
- Encryption processes
When effectively implemented, tokenization PCI DSS solutions will help streamline PCI compliance processes and mitigate unwanted exposure of sensitive PANs.
Encryption and HIPAA Parallels to Tokenization and PCI DSS Compliance
Parallels can be drawn between HIPAA regulatory adherence and PCI tokenization. For example, encryption can help prevent a potential HIPAA violation that would otherwise constitute unauthorized or improper use and disclosure simply because the data can’t be read.
What are the PCI DSS Tokenization Requirements?
Tokenization PCI DSS efforts must also align with PCI DSS Requirements 1, 3, 4, 6, 7, and 8, which aim to secure CHD throughout processing.
Tokenization implementations must ensure:
- Tokenization and de-tokenization processes do not reveal sensitive PAN to any application, user, system, or network outside a defined CDE (Requirement 3).
- System components involved in tokenization processes are hosted on secure internal networks and isolated from external, out-of-scope networks (Requirement 1).
- Communication across tokenization system environments is secured (Requirements 1 and 4).
- Use of strong cryptographic and security protocols to secure the storage and transmission of CHD across open, public networks (Requirement 4)
- Implementation of robust access control measures to secure CDE (Requirements 7 and 8)
- Maintenance of strict configuration standards for tokenization systems to adequately mitigate security gaps and vulnerabilities (Requirements 1 and 6)
- Secure disposal of CHD as defined by a PCI DSS data retention policy (Requirement 3)
- Established security processes for event logging, threat monitoring, and incident response for any identified malicious activity (Requirement 6)
Compliance with the PCI DSS tokenization Requirements will help mitigate cybersecurity threats against CHD and provide a baseline for designing a PCI-compliant tokenization system.
Tokenization PCI DSS System Design
The PCI DSS tokenization Requirements also mandate that organizations implement tokenization systems to secure PAN and minimize data breach risks.
Specifically, a PCI-compliant tokenization system design must ensure the secure creation, mapping, storage, and overall management of cryptographic tools used in the tokenization of CHD.
PCI DSS Token Creation Requirements
The creation of cryptographic tokens involves processes including, but not limited to:
- Mathematically reversible cryptographic functions, powered by strong cryptographic keys and algorithms
- One-way non-reversible cryptographic functions, such as hashing
- Indexing, which involves the use of sequences or randomly generated numbers
When hashing and truncation are used to encrypt PANs within the same CDE, the hashed and truncated versions of PAN should not be stored in the same environment—except if there are stringent controls to prevent the correlation and reconstruction of the encrypted PAN.
Additional considerations for token creation include:
- Reconstruction of PANs should not be feasible with knowledge of tokens
- Prediction of full PANs should not be possible with access to token-to-PAN pairs
- Tokens should provide no value to cybercriminals if a system is breached
- PCI DSS Requirement 3.2 strictly prohibits the tokenization of sensitive authentication data
Compliance with the tokenization PCI DSS Requirements will help you generate robust tokens that effectively secure PANs.
PCI DSS Token Mapping Requirements
When tokens are created, they can be assigned to the original PAN via token mapping—enabling secure retrieval of either PAN or tokens for business operations.
Considerations for securing token mapping processes include:
- Restricting access to token mapping tools to only authorized users
- Monitoring the exchange of PANs for associated tokens for unauthorized use events
- Securing token mapping system components per PCI DSS tokenization guidelines
Protection of token mapping systems also extends to the card data vaults used to store tokens, which must be secured against security gaps and vulnerabilities.
PCI DSS Card Data Vault Requirements
PANs and tokens used in token mapping are stored in a card data vault, which must be secured at all times per the tokenization PCI DSS Requirements. Since the card data vault contains a repository of tokens and PANs, it is the most lucrative target for cybercriminals.
It is critical to implement robust access control safeguards for the card data vault to mitigate compromise to the tokenization system and subsequent data breach risks. For the most effective PCI-compliant safeguards, a PCI compliance advisor can help you optimize card data vault security controls.
Cryptographic Key Management Requirements
Processes for token creation, use, and protection must be securely managed to strengthen PAN encryption against cybersecurity threats.
PCI DSS tokenization guidelines for cryptographic key management include:
- Implementing security controls for card data vaults containing tokens and PANs
- Securing the generation and storage of cryptographic keys used to encrypt PAN
- Safeguarding token creation and de-tokenization processes
- Defining the scope of PCI DSS tokenization to restrict the availability of tokenization to any system, user, or application outside defined tokenization environments
If outsourcing tokenization processes, you must ensure that your preferred PCI tokenization vendor complies with the PCI DSS Tokenization Requirements. Remember that your organization holds PCI DSS compliance responsibility even if one of your third-party partners is at fault for the violation.
Optimize Your PCI Data Encryption and Tokenization
Implementing the right tokenization PCI DSS solutions strengthens your PCI security posture against common cybersecurity threats. Working with an experienced PCI compliance advisor will help you rethink and optimize your existing tokenization implementations.
Contact RSI Security today to learn more and get started!
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