Tamper-resistant ubiquitous data management

The rapid growth of ubiquitous computing impels mobile users to store personal data on the Web in order to increase data availability and facilitate data sharing among partners. However, Database Service Providers (DSP) arouse user’s suspicion because DSP’s privacy policies have been frequently dishonored [AKS02]. In addition, no one can fully trust traditional server-based security mechanisms against more and more frequent and malicious attacks [FBI03]. While clientbased security policies have been historically disregarded considering the vulnerability of client environments [Rus01], the emergence of hardware elements of trust in client devices drastically changes the situation [BoP02]. Secure tokens and smart cards plugged or embedded into different client devices are exploited today in a growing variety of applications (e.g., authentication, healthcare folders, digital right management). Chip-Secured XML Access (C-SXA) belongs to this new category of PETs (Privacy Enhancing Technologies) taking their security from tamper-resistant hardware devices. CSXA is a versatile XML-based Storage Manager and Access Right Controller embedded in a smart card. It evaluates the user’s privileges on on-board or external encrypted XML data and delivers the authorized subset of these data. Combining storage and access control in the same secured architecture allows tackling accurately two important issues: