Why Tokenization Beats Transparent Data Encryption for PCI DSS Compliance

Cyber-threats are rapidly evolving and breaches are on the rise. That makes compliance with the Payment Card Industry Data Security Standard (PCI DSS) ever more critical for organizations handline sensitive payment card data. A key aspect of this framework is safeguarding data at rest – but the requirements are changing. Disk- or partition-level encryption is no longer permissible to protect non-removable electronic media.

So what should complying organizations do? Among the options available to them, tokenization beats transparent data encryption (TDE) for several reasons.

Understanding PCI DSS Requirement 3.5.1.2

PCI DSS Requirement 3.5.1.2 specifically addresses the limitations of disk encryption. It states:

“If disk-level or partition-level encryption (rather than file-, column-, or field-level database encryption) is used to render PAN unreadable, it is implemented only as follows:

• On removable electronic media

OR

• If used for non-removable electronic media, PAN is also rendered unreadable via another mechanism that meets Requirement 3.5.1.”

(Source: PCI DSS)

Put simply, disk-level or partition level encryption is no longer sufficient for protecting PANs stored on non-removable media.

Tokenization vs. TDE

So what are the main differences between tokenization and TDE?

TDE is used to encrypt database files at the storage level. It encrypts the entire database, including backups and transaction logs, rendering them unreadable to unauthorized users. While TDE provides a layer of security, it is transparent to the application, meaning that authorized users and applications can access and decrypt the data seamlessly.

Tokenization is a process that replaces sensitive data elements, such as credit card numbers, with a non-sensitive equivalent called a token. The token has no exploitable value or meaningful relationship with the original data. When the original data is needed, an authorized application can request the clear text element.

There are two tokenization approaches – vaulted and vaultless. When it comes to data security, vaulted tokenization – where sensitive data is stored in a secure database (vault) – is considered outdated compared to vaultless. The latter eliminates the need for a central storage system by replacing sensitive data with unique tokens directly using deterministic algorithms or cryptographic functions.

Why Tokenization Is Preferable
Consider the following:

• Enhanced data security/reduced breach risk

Since tokens are not derived from the original data and have no inherent meaning, they are useless to attackers. Even if a malicious actor obtains the tokens, they cannot reverse-engineer them to retrieve the original data, without access to the deterministic algorithms or cryptographic functions. But with TDE, if an attacker gains access to the database server and the encryption keys, they can potentially decrypt and access all the stored data.

• More efficient security management

TDE inherits user permissions from the database server, meaning it encrypts data at the storage level but relies on existing database management system (DBMS) roles to control access. Thus, access to encrypted data is governed by the same user roles and permissions set up in the DBMS.
However, tokenization doesn’t rely on DBMS roles and permissions. Instead, it uses a central access system to allow better, more granular access control. This provides more consistent and efficient security management and reduces the risk of misconfiguration.

• Minimized compliance scope and costs

With tokenization, the areas that store, process or transmit cardholder data are minimized – since tokens do not contain any sensitive information and the tokenization engine is isolated from the database and application server. This can reduce compliance costs and the number of controls required, and simplify audits. However, TDE can’t reduce the scope, since it is implemented on a database server, can decrypt the data, and therefore technically has access to the data.

• Data-centric security for end-to-end protection

While TDE encrypts data at rest on a specific database, it doesn’t cover data in use or in transit. On the other hand, tokenization keeps sensitive data protected in all states and wherever it flows, ensuring that even if data is intercepted during processing, only tokens are exposed. Clear text data can be exposed to authorized users only if absolutely necessary. It also preserves data utility for business workflows and applications, supporting operational efficiency and innovation.

More robust and sustainable

Tokenization provides a more robust and sustainable solution for organizations looking to comply with PCI DSS requirements. It not only meets the standard's security mandates, but also offers enhanced protection against attacks, reduces compliance scope and costs, and minimizes the risk of data breaches. That in turn reduces the risk of costly non-compliance penalties and helps to build customer trust.

comforte Data Security Platform

Instead of solely securing the systems that store or process sensitive data, comforte empowers organizations to protect the data itself—everywhere, always, and permanently.

Our data-centric security platform discovers sensitive data elements and replaces them with non-sensitive placeholders meaningless to attackers while preserving their utility for processing and analytics. Our solutions help organizations mitigate the risks of data breaches, enable secure data utilization across business applications, and reduce the complexity of compliance with stringent regulations such as PCI DSS or GDPR.

For more information about comforte, contact us at info@solid8.co.za