PCI council clarifies merchant's cloud security obligations

The group charged with administering the Payment Card Industry Data Security Standard (PCI DSS) is now tackling merchants' security and compliance concerns around cloud usage.

The Payment Card Industry Security Standards Council (PCI SSC) on Thursday published a new supplement to help merchants select cloud service providers (CSPs), as well as implement best practices within their own business to safeguard data going to the cloud.

The guidance defines common service models for cloud environments, the roles of third-party CSPs and the businesses that hire them, and operational and technical security challenges faced by these organizations.

Bob Russo, general manager of the PCI SSC, told SCMagazine.com on Wednesday that retailers often are tripped up by access restrictions that third-party CSPs place on data in the cloud.

“You are on a server with 50 or 100 other customers, and [CSPs] sometimes put in the contract that they don't want merchants going through this information, because you might be getting into others people's data or territory,” Russo said. “But if you are a merchant, you are ultimately responsible for your client's card data.”

He added that many CSPs also outsource data to other providers.

“All of a sudden, your cardholders' data is not only hosted by your CSP, but by their third-party clients,” Russo said. “Understand where in the cloud your payment card data is, then understand who has the responsibility to protect that – and that this is in your contract.”

With the new guidance, auditors and merchants have further clarification on each party's duties. The best practices also place more responsibility on businesses to protect their customers.

Chris Brenton, director of security at San Francisco-based cloud security provider CloudPassage, was a PCI member who helped create the cloud guidance. Brenton told SCMagazine.com on Thursday that, unlike physical routers that segregate sensitive data hosted on servers, the cloud's parameters are virtual – a point that led some PCI auditors to believe compliance on that front was impractical.

“You could have one auditor say there's no physical routers, so there's no way to meet PCI compliance," Brenton said. "You could literally go to five different auditors and get five different answers."