In post-disaster situation, re-establishment of communication infrastructure is very critical task. For that delay tolerant network is used by smart phone users like volunteers or victims. In such fragile environment, data can be forwarded by store-carry-forward mechanism. So, for data delivery, multi-hop communication and proper cooperation among nodes are very important aspects. Volunteers are working by forming small groups. In such sensational environment secure and instantaneous group communication among volunteer nodes and to remote monitoring system is imperative as there can be various malicious nodes intentionally intercept and alter data for the purpose of fraudulence. So, proper mechanism is required to detect malicious nodes and encourage them to participate by giving them incentives. Here, the objective is to develop incentive based secure message exchange scheme for reliable data communication. Opportunistic network environment simulator is used for performance measurement.