As an accountant and a PCI Qualified Security Assessor (QSA), i’m seeing more and more auditors essentially provide audit and fieldwork services for both a SAS 70 and a PCI DSS assessment at the same time, then issue a PCI DSS Report on Compliance (ROC) and a SAS 70 Type II Service Auditor’s Report. While I am all for audit efficiencies, there does need to be some degree of engagement independence, both in an administrative manner (different engagement letters, etc.) and in terms of audit expertise (both CPA’s and QSA’s need to be involved in their respective assignments and committed to the work at hand).
Furthermore, SAS 70 audits will also examine areas not covered by PCI DSS assessments, and the same is true for PCI DSS assessments covering technical areas traditionally not under the scope of a SAS 70 audit. As professionals, we need to be careful in not blurring the lines and distinctions between CPA’s and QSA’s and still try to maintain professional indepedence in regards to the work that each does and what they are qualified to do.