Traditional computer systems and small distributed networks rely on users' authentication to provide security. However, this strategy is extremely inadequate for the increased flexibility of pervasive environments, where users join and leave frequently. Here, users want to discover services dynamically and share them safely taking into account some constraints such as limited computational power and decentralized management. In this paper, we propose a solution to this using a secure resource discovery model. Most of the prior research works on resource discovery assume a constant initial trust value because assignment of initial trust is a critical issue. Even in pervasive smart space, some service sharing may need high security. The level of service security therefore needs to be incorporated in initial trust assignment. In this paper, we present an Adaptive Initial trust and Demand aware Secure Resource Discovery (AJD-SRD) model for pervasive environment. We incorporate a Demand Unit in AID-SRD which enables efficient resource 3huring with unknown devices. AID-SRD also assigns initial trust considering the variable security need of dilferent services.