SECURE AND EFFICIENT INFORMATION MANAGEMENT IN DELAY(DISRUPTION) TOLERANT NETWORK

In environments like international military coalitions on the battlefield or multi-party relief work in a disaster zone, multiple teams are deployed to serve different mission goals by the command-and-control center (CC). They may need to survey damages and send information to the CC for situational awareness and also transfer messages to each other for mission purposes. However, due to the damaged network infrastructure in the emergency, nodes need to relay messages using the store and forward paradigm, also called Delay-tolerant Networks (DTNs). In DTN, the limited bandwidth, energy, and contacts among the nodes, and their interdependency impose several challenges such as sensitive data leakage to malicious nodes, redundant data generation, limited and delayed important message delivery, non-interested messages in storage, etc. We aim to focus on solving these challenges. We propose message fragmentation for secure message transfer because existing public-private-key cryptographic approaches may not work due to the unavailability of Public Key Infrastructure (PKI). Besides, to ensure more message delivery, redundant fragments are generated. However, too much redundancy may consume the energy and bandwidth of the nodes while transferring similar messages. Hence, we propose to send diverse content and limit the redundancy. Again, the dynamic environment we consider is prone to many adverse and sudden events. We aim to respond to these events by sending the event-related message to the CC fast with the help of intermediate nodes. The nodes are interested in certain types of content defined by their mission and interest. Therefore, we target to learn nodes\u27 interests using Reinforcement Learning so that the nodes can populate themselves with the messages according to their mission requirements and increase the collaboration among them. Our future work will include machine learning techniques for predicting important places where node encounters the most and to cache data for each other according to their interest, encounter frequency, and encounter locations --Abstract, p. i

Targeted Content-Sharing in a Multi-Group Dtn Application using Attribute-Based Encryption

In a battlefield, multiple groups operate with different missions, but their missions and groups can dynamically change based on the evolving situation. Due to the unavailability of network infrastructure after deployment, group members form a Delay Tolerant Network (DTN) which is prone to security attacks. Hence, based on the mission attributes, group memberships, nodes\u27 interests, and data tags determination, targeted contents need to be distributed in a secure fashion to different users. Though existing Attributes Based Encryption (ABE) can provide security of information, revoking a member from a group is always an issue in DTN as the Attribute Authority (AA) is unavailable to the DTN nodes. Therefore, we adopt the ReVOABE algorithm for a battlefield DTN application for targeted data forwarding based on mission attributes and content interests

Efficient Photo Crowdsourcing in Delay-Tolerant Networks with Evolving POIs

In a disaster or battlefield zone, the rescue workers, soldiers and other survivors (referred to as nodes) may need to survey the damages and send images to the command and control center (the server) in a hop by hop fashion in the absence of any communication infrastructure. The server considers some area/landmark as the point of interest (POI), and distributes the request to the nodes to collect more information about them. Nodes take photos of POIs and share them among each other using store and forward paradigm, called Delay-tolerant Networks (DTNs) to send them to the server. Due to highly intermittent contact characteristics of nodes in a DTN network, and bandwidth and storage limitations, redundant photos need to be omitted in this forwarding technique whereas photos that cover different angles and views of the targets need to be shared. Another challenge is that, over time, some server-listed POIs may not be of importance whereas some new POIs might be of interest. In this work, we propose a scheme that is able to dynamically update the list of POIs based on the current photo metadata, with reduced consumption of the bandwidth, energy and the storage at nodes by sending only important photos of POIs. We compare our proposed schemes with a related well-known scheme [21] to show the scalability of our approaches which provide the same level of photo coverage, but consumes much less energy and bandwidth

Prioritized Content Determination and Dissemination using Reinforcement Learning in DTNs

In a battlefield, several groups of soldiers are deployed with different missions by the command and control center (CC). To continue the missions appropriately and get a better understanding of the situation, the soldiers as well as the CC need to collect information of interest generated in different battle zones using Delay-tolerant Networks (DTN). It is a challenge to determine the topics of interest associated with the events and missions, and efficiently forward the associated content to the CC in this extreme situation. We design a scheme to forward contents generated by the nodes to the CC using Reinforcement Learning (RL) while maximizing the number of interesting data in the respective nodes buffer, and avoiding congestion. In this forwarding process, we focus on identifying the trending topics/keywords among changing missions and their related data at the node level, and the changes of interest of the nodes based on their mobility and connectivity patterns of nodes in DTN. Experiments are conducted using real datasets and ONE simulator to show the effectiveness of Reinforcement Learning (RL) on the prioritized content dissemination in DTN networks

Efficient Photo Crowdsourcing with Evolving POIs under Delay-Tolerant Network Environment

In a disaster or battlefield zone, rescue workers, soldiers, and other survivors (referred to as nodes) may need to survey damages and send images to the command and control center (the server) in a hop-by-hop fashion in the absence of any communication infrastructure. The server considers some area/landmark as the point of interest (POI) and distributes a request to the nodes to collect more information about them. Nodes take photos of POIs and share them with each other using the store and forward paradigm, also called Delay-tolerant Networks (DTNs), to send the photos to the server. Due to the highly intermittent contact characteristics of nodes in a DTN network and bandwidth and storage limitations, redundant photos need to be removed in this forwarding technique, whereas photos that cover different angles and views of the POIs need to be shared. Another challenge is that, over time, some server-listed POIs may not be of importance anymore, whereas some new POIs might be of more interest. In this work, we propose a scheme that is able to dynamically update the list of POIs based on the current photo metadata, with reduced consumption of the bandwidth, energy, and storage at DTN nodes by sending only important photos of POIs. In the performance evaluation, we show the scalability of our approach, and also show that it provides the same level of photo coverage but consumes much less energy and bandwidth than other related schemes

Secure Information Forwarding through Fragmentation in Delay-Tolerant Networks

In application environments like international military coalitions or multi-party relief work in a disaster zone, passing secure messages using Delay Tolerant Networks (DTNs) is challenging because existing public-private key cryptographic approaches may not be always accessible across different groups due to the unavailability of Public Key Infrastructure (PKI). In addition, connectivity may be intermittent so finding the reliable route is also difficult. Thus, instead of sending the complete message in a single packet, fragmenting the messages and sending them via multiple nodes can help achieve better security and reliability when multiple groups are involved. Therefore, encrypting messages before fragmentation and then sending both the data fragments and the key fragments (needed for decryption) provide much higher security. Keys are also fragmented as sending the key in a single packet can hamper security if it is forwarded to some corrupted nodes who may try to tamper or drop it. Hence, in this paper, we develop a scheme to provide improved security by generating multiple key-shares and data fragments and disseminating them via some intermediate nodes. In this fragmentation process, we also create a few redundant blocks to guarantee higher data arrival rate at the destination when message drop rate is higher like in the DTN environment. Our performance evaluation when compared to the most closely related scheme like Multiparty Encryption shows the improvement on minimizing the number of compromised messages as well as reduced bandwidth consumption in the network