We describe the design and implementation of a secure and robust architectural data management model suitable for cultural environments. Usage and exploitation of the World Wide Web is a critical requirement for a series of administrative tasks such as collecting, managing and distributing valuable cultural and artistic information. This requirement introduces a great number of Internet threats for cultural organizations that may cause huge data and/or financial losses, harm their reputation and public acceptance as well as people's trust on them. Our model addresses a list of fundamental operational and security requirements. It utilizes a number of cryptographic primitives and techniques that provide data safety and secure user interaction on especially demanding on-line collaboration environments. We provide a reference implementation of our architectural model and discuss the technical issues. It is designed as a standalone solution but it can be flexibly adapted in broader management infrastructures.