Hash-Based Anonymous Secure Routing Protocol in Mobile Ad Hoc Networks A mobile ad hoc network (MANET) is composed of multiple wireless mobile devices in which an infrastructure less network with dynamic topology is built based on wireless communication technologies. Novel applications such as location-based services and personal communication Apps used by mobile users with handheld wireless devices utilize MANET environments. In consequence, communication anonymity and message security have become critical issues for MANET environments. In this study, a novel secure routing protocol with communication anonymity, named as Hash-based Anonymous Secure Routing (HASR) protocol, is proposed to support identity anonymity, location anonymity and route anonymity, and defend against major security threats such as replay attack, spoofing, route maintenance attack, and denial of service (DoS) attack. Security analyses show that HASR can achieve both communication anonymity and message security with efficient performance in MANET environments.