Resilient Data Collection in Smart Grid

Sensors and measurement devices are widely deployed in Smart Grid (SG) to monitor the health of the system. However, these devices are subject to damage and attack so that they cannot deliver sensing data to the control center. In tree-based data collection schemes, a relay failure can further lead to unresponsiveness of all the devices in its sub-tree. In this paper, we study the resiliency issue in collecting data from SG measurement devices. We first design a protocol that guarantees successful data collection from all non-faulty devices in a backup-enabled tree structure. Then, we formulate the tree construction problem to optimize data collection time. Since the formulated problem is NP-hard, we propose a heuristic algorithm to solve it. We evaluate our algorithm using a real utility network topology. The experiment results show that our algorithm performs well in large scale networks.CREDCOpe

Secure and Scalable Data Collection With Time Minimization in the Smart Grid

Deployment of data generation devices such as sensors and smart meters have been accelerating toward the vision of smart grid. The volume of data to be collected increases tremendously. Secure, efficient, and scalable data collection becomes a challenging task. In this paper, we present a secure and scalable data communications protocol for smart grid data collection. Under a hierarchical architecture, relay nodes [also known as data collectors (DCs)] collect and convey the data securely from measurement devices to the power operator. While the DCs can verify the integrity, they are not given access to the content, which may pave the way for third party providers to deliver value-added services or even the data collection itself. We further present optimization solutions for minimizing the total data collection time.This work was supported by the Department of Energy under Award DE-OE0000097Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111642/3/Uludag2015Secure_ToSG.pd

Secure Data Collection in Constrained Tree-Based Smart Grid Environments

To facilitate more efficient control, massive amounts of sensors or measurement devices will be deployed in the Smart Grid. Data collection then becomes non-trivial. In this paper, we study the scenario where a data collector is responsible for collecting data from multiple measurement devices, but only some of them can communicate with the data collector directly. Others have to rely on other devices to relay the data. We first develop a communication protocol so that the data reported by each device is protected again honest-but-curious data collector and devices. To reduce the time to collect data from all devices within a certain security level, we formulate our approach as an integer linear programming problem. As the problem is NP-hard, obtaining the optimal solution in a large network is not very feasible. We thus develop an approximation algorithm to solve the problem. We test the performance of our algorithm using real topologies. The results show that our algorithm successfully identifies good solutions within reasonable amount of time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111643/1/Uludag_IEEE_SGC_14.pd

DelPHIX: A Simple and Efficient Mechanism for Wormhole Detection in Ad Hoc Networks

Data transmission in a mobile ad hoc network is performed within an untrusted wireless environment. It is subjected to many kinds of security attacks. In a wormhole attack, two malicious nodes work together to tunnel packets from one to the other, making other nodes perceive a path to have a smaller hop count. We identify two types of wormhole attacks. In the first type, malicious nodes do not expose themselves in route finding process and legitimate nodes do not know their existence. In the second type, malicious nodes do create route advertisements and legitimate nodes are aware of the existence of malicious nodes, just do not know they are malicious. Existing solutions usually can identify only one kind of attacks. In this paper, we propose a simple and efficient detection method called DelPHIX. By observing the delays of different paths to the receiver, the sender is able to detect both kinds of wormhole attacks. This method requires neither synchronized clocks nor special hardware to be equipped in mobile nodes. The performance of DelPHIX is justified by simulations

Routing with QoS Information Aggregation in Hierarchical Networks

Abstract-In this paper, we consider the problem of routing with two additive constraints in the hierarchical networks, such as the Internet. In order for scalability, the supported QoS information in the hierarchical networks has to be aggregated. We propose a novel method for aggregating the QoS information. To the best of our knowledge, our approach is the first study to use the area-minimization optimization, the de facto optimization problem of the QoS information aggregation. We use a set of real numbers to approximate the supported QoS between different domains. The size of the set is predefined so that advertisement overhead and the space requirement will not grow exponentially as the network size grows. The simulation results show that the proposed method outperforms the existing methods

Resilient Data Collection in Refinery Sensor Networks Under Large Scale Failures

Wireless sensors and measurement devices are widely deployed in oil and gas refineries to monitor the health of the pipes. These sensors are deployed along the pipes in an open area and thus are subject to large scale failures due to cyber-physical attacks and hazardous environments. In this paper, we study the resilience issues in collecting data from a dense and large scale set of sensors deployed over the physical refinery pipe network. We construct a multi-tree sensor mesh network over the refinery sensors for data collection. The reporting messages within one of the trees, while passing along the tree, are protected by a secret key shared among all sensors on the tree. Our construction aims to minimize the data collection time and ensures that the information leakage probability of the secret key is bounded. To tolerate large scale failures, we present a distributed self-healing protocol, which enables a tree node to discover a secondary path when its parent fails. The simulation result shows that the self-healing protocol tolerates large scale failures with high probability and has small overhead in data collection time.Ope

HyBloc: Localization in Sensor Networks with Adverse Anchor Placement

To determine the geographical positions of sensors, numerous localization algorithms have been proposed in recent years. The positions of sensors are inferred from the connectivity between sensors and a set of nodes called anchors which know their precise locations. We investigate the effect of adverse placement and density of anchors on the accuracies of different algorithms. We develop an algorithm called HyBrid Localization (HyBloc) to provide reliable localization service with a limited number of clustered anchors. HyBloc is distributed in nature with reasonable message overhead. Through simulations, we demonstrate that HyBloc provides more accurate location estimates than some existing distributed algorithms when there are only a few anchors. HyBloc also performs well when anchors are clustered together