The work in this book represents a master's dissertation in mobile ad hoc networks (MANETs) security. The author has successfully managed to develop a lightweight and a reliable protocol to secure packet forwarding in civilian applications adopting MANETs communications. This is performed through proposing a novel algorithm (REEF-IDA) that is based on two protocols: reliable and efficient forwarding (REEF) and information dispersal algorithm (IDA). The simulation study shows that the REEF-IDA offers higher throughput, lower end-to-end delay and lower packet loss ratio when compared to its limited version, the REEF protocol. What is interesting in the results that REEF-IDA is resilient to the increasing mobility and the increasing number of adversaries, while on the other hand, REEF’s performance dramatically falls down when mobility and/or number of adversaries increase. REEF-IDA achieves up to 114.29% more throughput while decreases both the end-to-end delays and the packet loss ratio up to 100% less than those of REEF.