Many wireless systems have been proposed and deployed for decades. However, most of them are incompatible. It is expected that various wireless systems will still coexist in the near future. How to integrate them, thus, is an important issue. The integration should be done in both radio access network (RAN) and core network. A mobile user could overcome the incompatibility of different RANs by using multiple radio interfaces or software defined radio (SDR). However, it still requires a common core network to achieve universal roaming. If it is not possible to deploy a common core network, different core networks should be compatible. Unfortunately, standard organizations have been defining their own core networks. The roaming among heterogeneous networks, thus, has become a challenge. Earlier, we have proposed Reconfigurable Architecture and Mobility Platform (RAMP) to address this issue. However, RAMP mainly considers mobility management. In this paper, we present secure RAMP (sRAMP) which extends RAMP to support reconfigurability in security. This paper presents the design and implementation of sRAMP. To demonstrate the feasibility of sRAMP, a testbed has been constructed. This paper also presents the experimental results conducted by using the testbed. Furthermore, a brief comparison between the proposed sRAMP and other related studies is also presented.