Summary: Assured information sharing among different organizations in a coalitional environment is an important first step in accomplishing many critical tasks. For example, different security agencies may need to share intelligence information for detecting terrorist plots. At the same, each organization participating in the assured information sharing process may have different incentives. In this paper, we explore the effects of different incentives and potential trust issues among organizations on the assured information sharing process by developing an evolutionary game theoretic framework. In addition, we provide extensive simulation analysis that illustrates the impact of various different information sharing strategies.