In The Security Vs. Compliance Battle Of The Mind, Security Is Winning
Written by Walter ConwayA 403 Labs QSA, PCI Columnist Walt Conway has worked in payments and technology for more than 30 years, 10 of them with Visa.
If ever there was an argument where security trumped compliance, the debate about tokenization versus encryption is it. Readers have made that point abundantly clear following a recent column describing the PCI scope reduction benefits of tokenization versus encryption. The shift in emphasis from compliance to being secure is not new, but I was struck by how pronounced a perspective change retailers are experiencing.
Andrew Jamieson’s comment emphasized security over scope reduction. He described how he would put more faith in the security of a tested and proven technology like encryption than he would in tokenization. I know Andrew as a PCI and crypto pro, and although we have never met, we have exchanged ideas and thoughts on PCI-related issues remotely for a couple of years.
Where we differ is that, based on my experience, not every merchant has the expertise to implement an encryption system as well as Andrew might. He works for a security firm. A retailer’s IT department has a lot of other things to manage, and encryption may not be a core strength internally. Properly deployed, strong encryption can protect cardholder data and be PCI compliant. But compliance alone is not my focus. I look at minimizing PCI scope.
Where a merchant has the expertise (internally or through a partner), encryption can protect cardholder data. I believe the PCI scope will be broader than a similar implementation with tokenization. I agree with Andrew that if it is properly done, the encryption solution could be secure. I also believe we both would agree that either choice, properly implemented, would be more secure than the other if that one is poorly implemented.
Jeff Man got readers thinking about the process, drawing parallels between tokenization and encryption and pointing out that tokenization, too, is ultimately reversible. I know Jeff as a respected QSA and a crypto expert with impressive experience. He made the point that both processes are subject to compromise: Either the encryption keys or the token vault could be inadequately protected.
Cards issued by European banks when used online cross border don't usually support AVS checks. So, when a European card is used with a billing address that's in the US, an ecom merchant wouldn't necessarily know that the shipping zip code doesn't match the billing code.
-Marc
