The ever increasing diversity and mobility of devices have originated a marked rise in ubiquitous resources; a great number of collaborative applications could be exploited just by employing an efficient ubiquitous resource management mechanism. The CARM (Composable-Adaptive Resource Management) middleware-based architecture provides a flexible infrastructure where personal devices create seamlessly on demand interconnections links to share ubiquitous resources. In this article we address CARM's security challenges and to overcome these we propose the CARM Authorization (CARMA) module; in CARMA each user acts as an Attribute Authority (AA) responsible of issuing Attribute Certificates (ACs) and defining for each resource a set of policy-based authorization decisions; CARMA's Alerting System (AS) allows users to work in a collaborative mode by warning others of malicious nodes even when no infrastructure is available. This research mainly describes ongoing work towards a proof-of-concept implementation in the given scenarios. Our proposal enforces security considering the bandwidth efficiency and therefore enhancing the dynamic resource management experience in ubiquitous environments.