Key management (KM) and secure routing (SR) are two most important issues for Mobile Ad-hoc Networks (MANETs), but previous solutions tend to consider them separately. This leads to KM-SR interdependency cycle problem. In this paper, we propose an integrated KM-SR scheme that addresses KM-SR interdependency cycle problem. By using identity based cryptography (IBC), this scheme provides security features including confidentiality, integrity, authentication, freshness, and non-repudiation. Compared to symmetric cryptography, traditional asymmetric cryptography and previous IBC schemes, this scheme has improvements in many aspects. We provide theoretical proof of the security of the scheme and demonstrate the efficiency of the scheme with practical simulation.