Vehicular Ad Hoc Network (VANET) is a new paradigm of wireless network. Reliable and efficient unicast and multicast routing protocols are critical for VANETs. As a possible solution, opportunistic routing (OR) has received much attention recently. This paper focuses on the aspect of soft security by building trust opportunistic forwarding model in VANET. It incorporates the trust mechanism into OR to enhance the security of routing in resisting malicious attacks. In this paper, we proposed a trusted minimum cost opportunistic unicast routing protocol (TMCOR) and a multicast routing protocol (TMCOM). The simulation results show TMCOR and TMCOM have good throughput, average delay and security gains compared with existing protocols.