Evan Schuman's StorefrontBacktalk

Therefore, I’d like now to introduce a third column to our spreadsheet that will further inform our SLA. That column has the details on how you will validate the CSP is indeed meeting that particular requirement every day of the year.

I have trouble understanding how any CSP will help a merchant meet some particular PCI requirements. The example that comes to mind is the requirement for daily log review (10.6). I wonder how a merchant can reasonably outsource that requirement or even why it would want to. A multi-tenant cloud compounds the problem, because the vendor’s logs will have information on the other organizations sharing the cloud. In this case, the vendor will understandably be reluctant to share the logs, but PCI requires it. I still haven’t completely figured that one out.

I cannot see how any CSP can be expected to monitor your logs effectively. The reason is the provider has no context to evaluate the alerts. For example, how can a CSP know to red flag an admin logging in at 3 A.M. when only you know that person is on vacation?

Substitute “File Integrity Monitoring” (Requirements 11.5 and 10.5.5) for “daily log review” in the above paragraphs, and you have another awkward situation. And in no situation that I can imagine will a merchant be able to outsource its security policies (Requirement 12)—in particular, incident response planning. More likely, the CSP and the customer will need to coordinate their respective response plans to reconcile differences in policy, procedure, disclosure, legal issues and forensics. I would not underestimate the importance of coordinating incident response planning, given the extreme sensitivity of any data breach.

If I were a merchant looking at a cloud vendor, I would not be afraid to ask a lot of questions and make a lot of demands. At the recent RSA Conference, I heard one prominent CSP tell an audience of potential customers that they (the audience) needed to start making tougher demands and asking hard questions of their cloud providers. Otherwise, his company and others would never provide the necessary functions and services. That was a refreshing bit of honesty that too many people in the audience may not have heard. If so, that’s too bad, because I agree with that speaker.

Another person I spoke with at RSA was Bob Russo, General Manager of the PCI Security Standards Council. I asked him if he thought PCI DSS was ready for cloud computing. He thoughtfully turned the question back at me. He said that PCI as a standard was definitely ready for the cloud, but the better question might be: Is the cloud ready for PCI?

That is a good question, and one that many potential cloud customers and their QSAs will be asking, too. The emergence of PCI-compliant cloud providers is a positive sign. But it is not a free ride on PCI requirements. Even in the most full service of SaaS clouds a merchant will have some PCI responsibilities. If nothing else, there will be Requirement 12.

Merchants using clouds of all flavors will need to validate that their cloud provider performs per their contract and PCI requirements. Simply taking the cloud provider’s Attestation of Compliance and checking the “yes” box on all the PCI requirements will not cut it with too many QSAs. Like I’ve said many times, PCI has outlawed silver bullets.

What do you think? Are you considering a cloud-based payment solution? I’d like to hear your thoughts and experiences. Either leave a comment or E-mail me at wconway@403labs.com.