If I store cardholder details (PAN, Expiry etc.) in a Memcached data bucket, is that something to worry about in terms of PCI DSS compliance?
Our database is in a data center and is encrypted. Our web server is also in this data center. If I cache cardholder details on a Memcached server node which is running on the same box as the web server, or on a different machine on the same subnet as the web server, do I need to obfuscate or encrypt this cached data?
My initial thought is 'no' because we aren't persisting the data; it's all temporary storage.
edit: our current architecture is PCI-DSS compliant; we were deemed compliant a few months ago. Now it's a matter of remaining that way.