Trust Tshepo Mapoka

A New Multiple Service Key Management Scheme for Secure Wireless Mobile Multicast

Addressing key management in mobile multicast communication is currently a booming topic due to the convergence of wireless and mobile technologies. With the proliferation of multiple group based services that are possible to co-exist within a single network, mobile subscribers could subscribe to these services concurrently while ubiquitous. However, the existing group key management (GKM) protocols intend to secure group communication for just a single group service. The GKM approaches involve inefficient use of keys and huge rekeying overheads, hence unsuitable for multiple multicast group environments. In this paper, we propose a novel GKM protocol for multiple multicast groups, called slot based multiple group key management (SMGKM) scheme. SMGKM supports the movement of single and multiple members across a homogeneous or heterogeneous wireless network while participating in multiple group services with minimized rekeying transmission overheads. Unlike conventional GKM protocols, SMGKM protocol can mitigate one-affect-n phenomenon, single point of failure and investment pressure of signaling load caused by rekeying at the core network. Numerical analysis and simulation results of the proposed protocol show significant resource economy in terms of communication bandwidth overhead, storage overheads at the Domain Key Distributor (DKD), mobile receiver and Area Key Distributors while providing intense security.

Novel rekeying approach for secure multiple multicast groups over wireless mobile networks.

Mobile multicast is recently becoming a hot research in the convergence of wireless and mobile technologies. With the emergence of various multicast-based services, multiple multicast groups are possible to exist within a single network, and mobile subscribers could subscribe to multiple groups concurrently. However, the existing group key management (GKM) protocols intend to secure group communication for just a single group service. The GKM approaches involve inefficient use of keys and huge rekeying overheads, hence unsuitable for multiple multicast group environments. In this paper, we propose a novel GKM protocol for multiple multicast groups, called slot based multiple group key management (SMGKM) scheme. SMGKM supports the movement of single and multiple members across a homogeneous or heterogeneous wireless network while participating in multiple group services with minimized rekeying transmission overheads. Unlike conventional GKM protocols, SMGKM protocol mitigates 1-affect-n phenomenon, single point of failure and investment pressure of signaling load at the core network. The results of the proposed protocol show resource economy in terms of communication bandwidth and storage overheads.

Efficient authenticated multi-service group key management for secure wireless mobile multicast

Recently there is high demand for ubiquitously distributing multimedia services to mobile subscribers by Internet Service providers (ISPs). These services can be restricted to authorized subscribers via integration of authentication and group key management (GKM). It is expected that significant key management overhead will rise due to diverse subscription of multi-services co-existing in the same network concurrently. In this paper, we propose a scalable decentralized multi-service GKM scheme considering host mobility in wireless environment. Both authentication and key management phases are delegated from the trusted domain key distributor (DKD) to the area key distributors (AKD). Therefore Key distribution and authentication are handled at the AKD level in a distributed fashion without involving the DKD. This alleviates unnecessary delays and possible bottlenecks at the DKD. We show by simulation that the proposed scheme shows resource economy in terms of optimized rekeying communication overheads. The security performance studies also shows resilience to various attacks.

Handover Optimised Authentication Scheme for High Mobility Wireless Multicast

In this paper a distributed handover optimized authentication scheme based on independent session key per access network (HOISKA) is developed for the decentralized multi-service group key management scheme over wireless mobile multicast. It enables a handover user Mi involved in multiple multicast service subscriptions to securely reuse the long term credential initially issued by the trusted authentication server (As) for deriving unique session keys per access network as it performs handover authentication across various access networks. The distributed nature of the scheme enables offloading the authentication function to the area network controllers (AKDs) such that As is not involved during handover exchange authentication signaling. This simplifies handover by reducing handover exchange signalling constituting to handover delays. Handover Access authentication (HAA) phase in HOISKA is presented then analyzed using the delay analytical model. The model proves efficacy by inducing minimum delays with less handover blocking probability while providing same level of security to the widely deployed handover authentication scheme.

An Evaluation of Spatial Modulation for MIMO Systems with QO-STBC

Simplified designs of multi-antenna systems with optimum efficiency are receiving attentions. Such simplicities also involve low cost architectures. In this study, we report an evaluation of a new multi-antenna scheme, namely, spatial modulation (SM) that is compared with quasi-orthogonal space time block codes (QOSTBC) scheme over Rayleigh fading channel. The SM scheme has been, earlier, compared with space time block codes (STBC) – a two antenna transmit diversity scheme that achieves full diversity when only two antennas are used. This is extended to QOSTBC scheme that absolves some decoding limitations to attain full diversity. It will be shown that, using the QOSTBC of similar architecture with the SM, even better performance can be achieved in favour of QOSTBC.

A Multi-service Cluster-Based Decentralized Group Key Management Scheme for High Mobility Users

Previous cluster based group key management schemes for wireless mobile multicast communication lack efficiency in rekeying the group key if high mobility users concurrently subscribe to multiple multicast services that co-exist in the same network. This paper proposes an efficient multi-service group key management scheme suitable for high mobility users which perform frequent handoffs while participating seamlessly in multiple multicast services. The users are expected to drop subscriptions after multiple cluster visits hence inducing huge key management overhead due to rekeying the previously visited cluster keys. However we adopt our already proposed SMGKM system with completely decentralised authentication and key management functions to address demands for high mobility environment with same level of security and less overhead. Through comparisons with existing schemes and simulations, SMGKM shows resource economy in terms of rekeying communication overhead in high mobility environment with multi-leaves.