Research in privacy-preserving routing for Mobile Ad Hoc Networks (MANETs) focuses on protecting user identity, location, and communication patterns while ensuring secure and efficient data transmission. Recent approaches employ lightweight cryptographic schemes, anonymous authentication, and trust-based routing mechanisms to prevent eavesdropping, traffic analysis, and identity disclosure. Techniques such as onion routing, group signature schemes, and blockchain-assisted anonymization are being integrated to enhance route confidentiality and resilience against active and passive attacks. These privacy-preserving routing protocols aim to achieve a balanced trade-off between security, energy efficiency, and routing performance, enabling trustworthy communication in dynamic and decentralized MANET environments.