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Security against Hardware Trojans (HT) is an important concern in integrated circuits (IC) design and fabrication. Most of the current HT detection methods are based on the golden model of circuit design. Further, some approaches require test pattern for HTs activation. In this paper, we propose SC-COTD (Sequential/Combinational Controllability and Observability features for hardware Trojan Detection), an effective hardware Trojan detection to get rid of both golden chip and test pattern limitations. SC-COTD uses both sequential and combinational testability measures to detect and locate HT signals by a machine learning approach. This method deploys an ensemble classifier based on k-means clustering. The clustering models have diverse variety in testability features along with size of clustering which inspect and reveal different aspects of netlist conventional for a collaborative scheme. The clustering results are filtered and then fed into a decision-making procedure based on majority voting to eliminate the limited flaws of each model. The evaluation results on TrustHUB benchmarks demonstrate that, SC-COTD can detect and locate HTs with 100% without any false negative, i.e., Recall = 1. Although our method has a limited number of false positive, it has the best performance in comparison to well-known previous approaches.

Subscriber authentication is a primitive operation in mobile networks required by each operator prior to offering any service to end users. In this paper, we propose a novel blockchain-based Authentication and Key Agreement (AKA) protocol for roaming services in 5G networks. Each Home Network (HN) creates its own smart contract and publishes its address to inform other operators who want to offer roaming services to HN subscribers. All subsequent communication between the HN and Serving Network (SN) is done by calling the function of this smart contract. The proposed protocol eliminates the need for a secure channel between the HN and SN, which is a primary requirement of current 5G AKA protocols. In practice, a secure channel requires the HN and SN to establish a secure session before running the AKA protocol. Further, the proposed protocol leverages the benefits of blockchain, such as auditable log, decentralized architecture, and the prevention of Denial of Service (DoS) attacks. Furthermore, we provide a security proof of the protocol through formal verification using ProVerif. The results show that our scheme tends to preserve user privacy and at the same time provides mutual authentication of the participants. Finally, our evaluation of the Ethereum blockchain shows that the protocol is efficient in terms of both transaction and execution costs.

In this paper, we propose INCP, inter-flow network coding protocol, for wireless mesh networks. INCP is designed with the concept of Layered Approach. It acts as a distinct layer above the MAC and has close cooperation with IP layer. INCP exploits the opportunities of network coding through multiple unicast sessions to decrease the number of transmissions, thereby increasing the aggregated throughput. Unlike most prior work that is mainly theoretical, INCP addresses the practical issues of network coding such as impact of lossy links, enabling/disabling RTS/CTS mechanism, packet size and its variation. We consider a retransmission mechanism to ensure a reliable broadcasting. We analyze the cost of this approach by providing a theoretical formulation for the amount of required bandwidth for successful broadcasting a coded packet to n neighbors. Further, we examine the coding gain for lossy networks by considering the ETX metric for routing in addition to traditionally shortest-path metric. The results, implemented in ns-3, show that not only INCP increases network throughput, but also improves the fairness of the IEEE 802.11 MAC. Moreover, the gain for real MAC is greater than the theoretical gain in most cases. The performance gain of INCP reaches up to several folds depending on the traffic model and congestion level.

In this paper, first, we propose Star-NC, a new network coding (NC) scheme for multiple unicast sessions in an n-input n-output star structure. Then, we evaluate the network throughput of this coding scheme in wireless mesh network over the traditional non-NC transmission. Our scheme benefits from the proximity of all the nodes around the relay node and employs a more general form of overhearing different from other schemes such as COPE. We found that the gain of our NC scheme depends on both the star size and the routing pattern of the unicast transmissions. Based on this, we identify both the situations which the maximum gain is achievable and a lower bound for the expected value of the gain in the case of random routing pattern. Next, we propose an analytical framework for studying throughput gain of our Star-NC scheme in general wireless network topologies. Our theoretical formulation via linear programming provides a method for finding source-destination routes and utilizing the best choices of our NC scheme to maximize the throughput. Finally, we evaluate our model for various networks, traffic models and routing strategies over coding-oblivious routing. We also compare the throughput gain of our scheme with COPE-type NC scheme. We show that Star-NC exploits new coding opportunities different from COPE-type NC and thus can be used with or without this scheme. The results show that Star-NC has often better performance than COPE for a directional traffic model which is a typical model in wireless mesh networks. Moreover, we found that, joint Star and COPE-type NC has better throughput performance than each of Star or COPE alone.

Throughput limitation of wireless networks imposes many practical problems as a result of wireless media broadcast nature. The solutions of the problem are mainly categorized in two groups; the use of multiple orthogonal channels and network coding (NC). The networks with multiple orthogonal channels and possibly multiple interfaces can mitigate co-channel interference among nodes. However, efficient assignment of channels to the available network interfaces is a major problem for network designers. Existing heuristic and theoretical work unanimously focused on joint design of channel assignment with the conventional transport/IP/MAC architecture. Furthermore, NC has been a prominent approach to improve the throughput of unicast traffic in wireless multi-hop networks through opportunistic NC. In this paper we seek a collaboration scheme for NC in multi-channel/interface wireless networks, i.e., the integration of NC, routing and channel assignment problem. First, we extend the NC for multiple unicast sessions to involve both COPE-type and a new proposed scheme named as Star-NC. Then, we propose an analytical framework that jointly optimizes the problem of routing, channel assignment and NC. Our theoretical formulation via a linear programming provides a method for finding source---destination routes and utilizing the best choices of different NC schemes to maximize the aggregate throughput. Through this LP, we propose a novel channel assignment algorithm that is aware of both coding opportunities and co-channel interference. Finally, we evaluate our model for various networks, traffic models, routing and coding strategies over coding-oblivious routing.

Fast Data Encryption (FDE) is a new symmetric block cipher which has a DES-like structure. FDE has been designed with an increased key length, increased key scheduling complexity and an improved round function which can be executed in parallel. FDE uses eight Substitution Boxes (S-boxes) in the round function to provide confusion. In this paper, we present the FDE structure and an algorithm to construct a set of strong S-boxes. Eight suitable S-boxes from this set are suggested for use with FDE.

We propose a new vertical handoff method in which the number of signaling and registration processes is lowered as a result of reduced utilization of home agent and correspondent nodes while users are mobile. Throughput performance of the integrated network is improved by reducing handoff delays and packet losses. Special conditions such as boundary condition also considered. Performance and delay evaluations which done by ns-2 are presented to demonstrate the effectiveness of the proposed scheme.

This paper introduces a novel vertical handoff method in which the number of signaling and registration processes is lowered as a result of reduced utilization of home agent and correspondent nodes while users are mobile. Throughput performance of the integrated network is improved by reducing handoff delays and packet losses. We also decrease the system energy by estimating user locations in comparison with the WLANs to decrease interface ontimes. Performance and delay results are presented to demonstrate the effectiveness of the proposed scheme.