In this article, we aim to clarify what requirements the Payment Card Industry Data Security Standard (PCI DSS) places around the protection of cardholder data (CHD) and, in particular, sensitive authentication data (SAD).
But first, a bit of a recap. The PCI DSS is an information security standard for organisations that store, process and/or transmit payment card data. In 2004, 5 major card brands (Visa, MasterCard, JCB, American Express and Discover*) joined forces to form the Payment Card Industry Security Standards Council (PCI SSC) and produced PCI DSS version 1 to help businesses process card payments securely and reduce card fraud. Since that time there have been various iterations of the Standard with the latest version (4.0) being released on31 March 2022 providing a set of baseline controls that is expected to be complied with by all organisations processing payment card data. .
When we refer to payment card data, however, a distinction is made between the storing, processing or transmitting of cardholder data (CHD) and sensitive authentication data (SAD). Here, we look at the differences and the extra PCI DSS requirements which apply to SAD.
*In 2020, UnionPay joined the founding 5 brands as a strategic partner on the Payment Card Industry Security Standards Council (PCI SSC)
CHD vs. SAD
The PCI DSS considers CHD and SAD as account data. CHD consists of a full primary account number (PAN) plus any of the following: cardholder name, expiration date and service code. It is worth noting that storage requirements of the PCI DSS apply to the PAN and the other data if it is stored in conjunction with the PAN. If you only store the other data without the PAN, then the storage requirements do not apply
SAD consists of the track data in the magnetic strip, the PIN and PIN block data stored in the chip and the verification code. Due to the different card brand naming conventions, the verification code is variously referred to as ‘card verification value’ (CVV2), ‘card authentication value’ (CAV2), ‘card verification code’ (CVC2) and ‘card identification number (CID). Visa uses the term CVV2, JCB uses CAV2, MasterCard uses CVC2 and American Express and Discovery both use CID.
For Discover, JCB, MasterCard and Visa payment cards, card verification values or codes are the rightmost 3-digit value printed in the signature panel on the reverse of the card. For American Express payment cards, the code is a 3-digit, unembossed number printed above the PAN on the face of the payment cards. The code is uniquely associated with each individual card and ties the PAN to the card.
With SAD, the PCI DSS places extra security requirements. Most significantly, unless issuers or issuing organisations have a legitimate business need to store the authentication data, SAD must never be stored after authorisation, even if encrypted. This applies even where there is no PAN in the environment. Organisations should also contact their acquirer or the individual payment brands directly to understand whether SAD is permitted to be stored prior to authorisation, for how long, and any related usage and protection requirements.