The document reviews the security challenges and proposed routing schemes in mobile ad hoc networks (MANETs), highlighting the difficulties posed by their decentralized nature and dynamic topology. It categorizes routing protocols into proactive, reactive, and hybrid types, and discusses various security approaches including key management and intrusion detection systems. The synthesis of historical and current secure routing protocols in MANETs underscores the need for tailored security solutions to address unique vulnerabilities inherent in such networks.