keywords: wireless, mobile, ad-hoc network, wide area network, Terminodes, incentive to co-operate, terminode beans

abstract  In this paper, we address the problem of service availability in mobile ad-hoc WANs. We present a secure mechanism to stimulate end users to keep their devices turned on, to refrain from overloading the network, and to thwart tampering aimed at converting the device into a ``selfish`` one. Our solution is based on the application of a tamper resistant security module in each device and cryptographic protection of messages.