In P2P data sharing systems (P2PDSS) peers share data in a pairwise fashion. Data are shared on-the-fly by establishing temporary data exchange session for user queries. Generally, the communication link between peers is unsecured while exchanging data. In P2P eHealth data sharing scenarios, peers may need to exchange highly confidential data among them. Hence, there are some security threats that need to be considered (e.g. data might be trapped and disclosed by the intruders). In a P2PDSS, the authors cannot assume any third party security infrastructure (e.g. PKI) to protect confidential data. Considering the need of secure data exchange in P2PDSS, in this paper, they propose a secure data exchange model. The model is based on pairing-based cryptography and the data sharing policy between peers.