Suresh Krishnan

Secure Route Optimization for MIPv6 Using Enhanced CGA and DNSSEC

With mobile phones evolving every year, it is no surprise that recent surveys have shown that the worldwide number of mobile phone subscriptions reached 5.6 billion in 2011, becoming the largest pool of interconnected devices. Since mobile IP is the most-used protocol by mobile operators, the obvious solution to support more users in their network would be to replace it with MIPv6. In addition to integrating the newest IP stack, MIPv6 adds an important feature meant to replace the inefficient triangle routing by allowing an MN to communicate bidirectionally with the CN without passing through its home agent. However, the lack of preshared information between the MN and CN makes security for this RO mechanism a difficult challenge. MIPv6 adopts the RR mechanism that is only to verify the MN reachability in both its home address and care-of address without being a security feature. Other works have attempted to solve the multiple security issues in RR, but either their design was flawed or their assumptions were unrealistic. This paper presents a secure MIPv6 with a secure and efficient RO that uses DNSSEC to validate CGAs from trusted domains and provides strong authentication rather than the weak sender invariance security property. It integrates an enhanced cryptographically generated address (ECGA) based on a backward key chain that offers support to bind multiple logically linked CGAs together. ECGA tackles the time-memory tradeoff attacks with high efficiency. The validation through both AVANTSSAR and AVISPA platforms show that the proposed solution has no security flaw while still being lightweight in signaling messages on the radio network.

An Efficient and Secure Self-Healing Scheme for LKH

With the growing interest in converging fixed and mobile networks (FMC), mobile applications will require more and more resources from both the network and the mobile device. In such context, multicasting is essential because it lowers bandwidth consumption by simultaneously reaching a group of multiple recipients. Securing multicast flows has been extensively studied in the past, but none of the existing solutions were meant to handle the constraints imposed by mobile scenarios, in particular the high packet-loss rate. The need for a low overhead self-healing rekeying mechanism that is scalable, reliable and suitable for mobile environments has never been more urgent than with the arrival of FMC in 4G networks. This paper presents two self-healing recovery schemes based on the dual directional hash chains (DDHC) for the logical key hierarchy (LKH) rekeying protocol. This enables a member that has missed up to m consecutive key updates to recover the missing decryption keys without asking the group controller key server (GCKS) for retransmission. Conducted simulations show considerable improvements in the ratio of decrypted messages and in the rekey message overhead in high packet loss environments.

ConEx based QoE feedback to enhance QoE

Quality of service (QoS) generally represents the performance of packet networks. Quality of experience (QoE) defines the quality perceived by end-users of applications running on these networks. This paper relates these two metrics in a novel way using the newly defined congestion exposure (ConEx) mechanism. ConEx is an experimental protocol defined by the IETF that allows the sender of a flow to convey the received explicit congestion notification (ECN) information back into the network. In IPv6, ConEx is implemented in an option header with 28 unused bits. These bits can be used to convey more than ECN feedback towards the network. This paper proposes to use these bits to send real-time objective QoE information, as perceived by the end-users, into the network. Routers can leverage this information to adjust QoS mechanisms. As an example, a new queue management technique is proposed with a multi-field DiffServ classifier using the QoE metric. Simulation results show that this mechanism can help in improving the overall QoE of active flows.

Simplified Wireless Connectivity for 5G Machine Type Communication

Ubiquity of applications supporting the networked society demands an efficient communication system to support Machine Type Communication (MTC) devices. The current architecture is not optimized for MTC traffic patterns and therefore, may lead to excessive signaling. In this paper, we propose a simplified approach to wireless connectivity to cope with the requirements of Massive MTC devices. The essence of our solution is based on an optimized and simplified IPv6 connectivity at the existing base stations for a large number of MTC devices while supporting the coexistence of legacy mobile devices. This paper focuses on the core network aspect of the end-to-end connectivity. By analyzing the signaling load we illustrate the feasibility of the proposed solution and demonstrate that it outperforms the existing architecture through simplification of connectivity and elimination of unnecessary functions.

Seamless handover for multicast mobile IPv6 traffic

MIPv6 is an IETF protocol that manages mobility, allowing a MN to continue to be reachable after an IP address change, result of a handover. However, when multicast applications are used, this address change results in a disruption of the service, because of the packet loss that occurs while the MN is rejoining the multicast group. Hence, we propose a new multicast scheme that provides a seamless multicast service during a handover in a MIPv6 network. The proposed scheme achieves its goal by adding a new node, denoted the MBA, whose role is to buffer the packets when the MN is performing the handover. These packets would otherwise be lost. We present an analysis of the buffer sizes to find the optimal sizes. Simulation results, obtained with OPNET, show that by properly sizing the buffers, seamless multicast handover can be achieved with the proposed scheme.