Version 2 of the PCI-DSS (Payment Card Industry – Digital Security Standard) that was released in October of last year (2010) finally added some much needed, if limited, clarification around the use of virtualised environments.
This change / clarification is an addition to section 2.2.1 of the standard, adding the statements;
Note: Where virtualization technologies are in use, implement only one primary function per virtual system component.
2.2.1.b If virtualization technologies are used, verify that only one primary function is implemented per virtual system component or device
While this does not clarify how to set up a virtual environment that handles card data to meet PCI-DSS it does at least make it very clear that the use of virtual environments is acceptable and can meet the standard.
This removes the previous confusion around the acceptability of of using virtualisation to host environments dealing with card data that stemmed from the statement in version one of the standard around each server having to have only a single function. By definition the physical hosts in a virtualised environment host multiple guests (the virtual servers) and thus have multiple functions.
Despite not having as much detail as many had hoped this is a great step forward given the ever increasing adoption of virtualisation to reduce costs and make better use of server hardware.
This has also opened the door to the possibility of using cloud based services to provide a PCI-DSS compliant architecture. During some recent research into virtual architecture that will meet the requirements of PCI-DSS 2 I came across this work from a combination of companies to provide a reference architecture for PCI-DSS compliance in a cloud based scenario;
The above links to both a webinar providing an overview of the work undertaken, and a white paper detailing the actual reference architecture.
The architecture design was undertaken by Cisco, VMWare, Savvis, Coalfire and Hytrust, and while the solution is understandably made up of the products and services offered by those companies, it clearly outlines a solution that you can adapt for your needs and make use of similar solutions that fit with your companies tech stack. As such this is a highly recommended read for anyone involved in designing or auditing solutions that need to be PCI-DSS compliant.