Secure Sharing of Tuple Spaces in Ad Hoc Settings**Please see WUCSE-03-26**

Practical applications of coordination models demand appropriate security guarantees. In ad hoc settings this must be achieved without reliance on any central point of control. \lime is one of the few coordination models and middleware to provide support for ad hoc networking and mobility. This paper shows how security can be added to \lime by simple extensions to the original model. The extensions include password protected tuple spaces, per tuple access controls and encrypted communication between parts of application running on different hosts. Furthermore, these new capabilities are accommodated with minimum changes to the original design