Wired equivalent security is difficult to provide in ad hoc networks due to high dynamics, wireless link vulnerability, and requirement of complete decentralization. Especially mutual authentication among nodes in a self-organized mode of ad hoc network, where a single definition of trust is hard to build, is very difficult. This leads to several loopholes in previously established security architectures and intrusion detection systems if employed to ad hoc networks. Also, typical to ad hoc routing major security lacks are unfair participation of nodes in the system, and frequent attacks to the routing protocols by ad hoc nodes that do not want to forward foreign packets but use other nodes to forward their own packets. Contrary to detection based approaches to tackle this situation, we propose a motivation based approach which does not require mutual authentication. We enable this by providing a) a realistic architecture of ad hoc access network to an ISP, b) a workable business model for charging in this architecture and c) necessary security protocol to implement the charging scheme. We propose for the latter a protocol specification and give a formal validation.