PCI info for those X-Cart users who use PayPal for your merchant account...
PayPal and PCI compliance (Website Payments Pro, Payflow Pro, or Virtual Terminal):
https://www.paypal.com/pcicompliance
PayPal helps (from the above link):
PayPal has partnered with ScanAlert, a Visa and MasterCard-certified PCI vendor, to help our customers comply at
no cost for the first year. Enroll online with ScanAlert at: https://www.scanalert.com/SignUp.sa?oc=9673.
PCI Data Security Standards Payment Card Industry Data Security Standards (PCI DSS) – are a set of network security and business practice guidelines adopted by major credit card companies to help protect customers’ payment card information. This
module reviews the 12 requirements all merchant websites must meet to comply with PCI DSS. We also explain how to validate compliance and how to implement and support PCI DSS when using a PayPal solution.
Module:
http://www2.eventsvc.com/paypaldev/event/0a654a52fd7a4c9db8ef81d3441f4c1d
PCI Compliance for PayPal Developers (PDF):
https://cms.paypal.com/cms_content/CA/en_US/files/developer/PP_PCI_Compliance_WhitePaper.pdf
PCI DSS Compliance – Website Payments Standard:
https://www.paypal.com/cgi-bin/webscr?cmd=xpt/Marketing/merchant/PCIComplianceDSS-outside
PDF:
https://www.paypalobjects.com/WEBSCR-620-20100330-1/en_US/pdf/PP_WebsitePaymentsStandard_PCIComplianceDSS.pdf
PCI Compliance Solutions:
https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/solutions_pci_compliance
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And from PCI Security Standards Council...
PCI DSS New Self-Assessment Questionnaire (SAQ) Summary V1.2:
https://www.pcisecuritystandards.org/saq/instructions_dss.shtml
Self-Assessment Questionnaire - Instructions and Guidelines v1.1 (PDF):
https://www.pcisecuritystandards.org/pdfs/instructions_guidelines_v1-1.pdf