Securing the transfer of data in mobile ad hoc networks (MANETs) is still a challenging issue. This paper proposes a method for providing message security in MANETs when nodes cooperate in routing. Our approach combines a trust-based multipath routing scheme and a real-time recurrent neural network-based (RRNN) cipher (yielding our so-called TR-RRNN scheme) to deal with the issues underlying message confidentiality, integrity, and access control. Simulation experiments using QualNet were conducted, showing that the proposed scheme is much more secured compared to the traditional multi-path routing algorithms and a recently proposed message security scheme for MANETs (our so- called Original Trust-based Multi-path Routing scheme (OTMR)). The route selection time and trust compromise are used as the performance criteria.