1,452 research outputs found

    Peer-to-Peer Secure Multi-Party Numerical Computation Facing Malicious Adversaries

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    We propose an efficient framework for enabling secure multi-party numerical computations in a Peer-to-Peer network. This problem arises in a range of applications such as collaborative filtering, distributed computation of trust and reputation, monitoring and other tasks, where the computing nodes is expected to preserve the privacy of their inputs while performing a joint computation of a certain function. Although there is a rich literature in the field of distributed systems security concerning secure multi-party computation, in practice it is hard to deploy those methods in very large scale Peer-to-Peer networks. In this work, we try to bridge the gap between theoretical algorithms in the security domain, and a practical Peer-to-Peer deployment. We consider two security models. The first is the semi-honest model where peers correctly follow the protocol, but try to reveal private information. We provide three possible schemes for secure multi-party numerical computation for this model and identify a single light-weight scheme which outperforms the others. Using extensive simulation results over real Internet topologies, we demonstrate that our scheme is scalable to very large networks, with up to millions of nodes. The second model we consider is the malicious peers model, where peers can behave arbitrarily, deliberately trying to affect the results of the computation as well as compromising the privacy of other peers. For this model we provide a fourth scheme to defend the execution of the computation against the malicious peers. The proposed scheme has a higher complexity relative to the semi-honest model. Overall, we provide the Peer-to-Peer network designer a set of tools to choose from, based on the desired level of security.Comment: Submitted to Peer-to-Peer Networking and Applications Journal (PPNA) 200

    Dinamička distribucija sigurnosnih ključeva i koalicijski protokol IP adresa za mobilne ad hoc mreže

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    In mobile adhoc networks (MANETs) a tree-based dynamic address auto-configuration protocol (T-DAAP) is one of the best protocols designed for address assignment as far as the network throughput and packet delays are concerned. Moreover, MANET security is an important factor for many applications given that any node can listen to the channel and overhear the packets being transmitted. In this paper, we merge the address assignment with the security key delivery into one protocol, such that a node in the MANET is configured with IP address and security key simultaneously. To the best of our knowledge, no single protocol provides concurrent assignment of IP addresses and security keys for MANET nodes. The proposed method, which is based on T-DAAP, shows significant enhancements in the required control packets needed for assigning network nodes IP addresses and security keys, MAC layer packets, total end-to-end delay, and channel throughput over those obtained when using separate protocols. Additionally, it provides not only efficient security keys to the nodes from the first moment they join the network, but also secure delivery of the address and security key to all participating nodes. It is noteworthy to mention that providing a complete security model for MANET to detect and countermeasure network security threats and attacks is beyond the scope of our proposed protocol.Kod mobilnih ad hoc mreža (MANET) dinamički protokol za autokonfiguraciju adresa baziran na stablu (T-DAAP) je jedan od najboljih protokola dizajniranih za dodjelu adresa iz perspektive propusnosti mreže i i kašnjenja paketa. štoviše, sigurnost MANET-a je važan faktor za mnoge aplikacije s obzirom da bilo koji čvor može osluškivati kanal i slučajno čuti pakete koji se šalju. U ovom radu, dodjela adresa i dostava sigurnosnih ključeva spojeni su u jedan protokol tako da je čvor u MANET-u konfiguriran simultano s IP adresom i sigurnosnim ključem. Prema saznanjima autora, niti jedan postojeći protokol ne pruža istovremeno dodjeljivanje IP adrese i sigurnosnog ključa za MANET čvorove. Predložena metoda, koja se bazira na T-DAAP-u, pokazuje značajna poboljšanja u odnosu na metode koje koriste odvojene porotokole, kod traženih kontrolnih paketa koji su potrebni za dodjeljivanje IP adresa i sigurnosnih ključeva čvorovima mreže, MAC paketa, ukupnog end-to-end kašnjenja i propusnosti kanala. Dodatno pruža ne samo efikasne sigurnosne ključeve čvorovima od trenutka kad se priključe mreži, nego i sigurno dostavljanje adrese i sigurnosnog ključa svim čvorovima koji sudjeluju u mreži. Važno je spomenuti da je pružanje cjelokupnog sigurnosnog modela za MANET koji detektira dodatno i protumjere prijetnjama i napadima na sigurnost mreže izvan dosega predloženog protokola

    A STABLE CLUSTERING SCHEME WITH NODE PREDICTION IN MANET

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    The main concern in MANET is increasing network lifetime and security. Clustering is one of the approaches that help in maintaining network stability. Electing an efficient and reliable Cluster Head (CH) is a challenging task. Many approaches are proposed for efficient clustering, weight-based clustering is one among them. This paper proposes a stable clustering scheme which provides network stability and energy efficiency. Proposed Stable Clustering Algorithm with Node Prediction (SCA-NP) computes the weight of the node using a combination of node metrics. Among these metrics, Direct Trust (DT) of the node provides a secure choice of CH and Node Prediction metric based on the minimum estimated time that node stay in the cluster provides the stable clustering. Mobility prediction is considered as the probability that a node stays in the network. This metric helps in electing CH which is available in the network for a longer time. Simulation is done in NS3 to evaluate the performance of SCA-NP in terms of clusters formed, network lifetime, efficiency in packet delivery, detecting malicious nodes and avoiding them in communication

    Hybrid Deep Learning Algorithm for Insulin Dosage Prediction Using Blockchain and IOT

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    This paper addresses the problem of predicting insulin dosage in diabetes patients using the PSO-LSTM, COA-LSTM, and LOA-LSTM algorithms. Accurate insulin dosage prediction is crucial in effectively managing Diabetes and maintaining blood glucose levels within the desired range. The study proposes a novel approach that combines particle swarm optimization (PSO) with the long short-term memory (LSTM) model. PSO is used to optimize the LSTM's parameters, enhancing its prediction capabilities specifically for insulin dosage. Additionally, two other techniques, COA-LSTM and LOA-LSTM, are introduced for comparison purposes. The algorithms utilize a dataset comprising relevant features such as past insulin dosages, blood glucose levels, carbohydrate intake, and physical activity. These features are fed into the PSO-LSTM, COA-LSTM, and LOA-LSTM models to predict the appropriate insulin dosage for future time points. The results demonstrate the effectiveness of the proposed PSO-LSTM algorithm in accurately predicting insulin dosage, surpassing the performance of COA-LSTM and LOA-LSTM. The PSO-LSTM model achieves a high level of accuracy, aiding in personalized and precise insulin administration for diabetes patients. By leveraging the power of PSO optimization and LSTM modeling, this research improves the accuracy and reliability of insulin dosage prediction. The findings highlight the potential of the PSO-LSTM algorithm as a valuable tool for healthcare professionals in optimizing diabetes management and enhancing patient outcomes

    Privacy preserving linkage and sharing of sensitive data

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    2018 Summer.Includes bibliographical references.Sensitive data, such as personal and business information, is collected by many service providers nowadays. This data is considered as a rich source of information for research purposes that could benet individuals, researchers and service providers. However, because of the sensitivity of such data, privacy concerns, legislations, and con ict of interests, data holders are reluctant to share their data with others. Data holders typically lter out or obliterate privacy related sensitive information from their data before sharing it, which limits the utility of this data and aects the accuracy of research. Such practice will protect individuals' privacy; however it prevents researchers from linking records belonging to the same individual across dierent sources. This is commonly referred to as record linkage problem by the healthcare industry. In this dissertation, our main focus is on designing and implementing ecient privacy preserving methods that will encourage sensitive information sources to share their data with researchers without compromising the privacy of the clients or aecting the quality of the research data. The proposed solution should be scalable and ecient for real-world deploy- ments and provide good privacy assurance. While this problem has been investigated before, most of the proposed solutions were either considered as partial solutions, not accurate, or impractical, and therefore subject to further improvements. We have identied several issues and limitations in the state of the art solutions and provided a number of contributions that improve upon existing solutions. Our rst contribution is the design of privacy preserving record linkage protocol using semi-trusted third party. The protocol allows a set of data publishers (data holders) who compete with each other, to share sensitive information with subscribers (researchers) while preserving the privacy of their clients and without sharing encryption keys. Our second contribution is the design and implementation of a probabilistic privacy preserving record linkage protocol, that accommodates discrepancies and errors in the data such as typos. This work builds upon the previous work by linking the records that are similar, where the similarity range is formally dened. Our third contribution is a protocol that performs information integration and sharing without third party services. We use garbled circuits secure computation to design and build a system to perform the record linkages between two parties without sharing their data. Our design uses Bloom lters as inputs to the garbled circuits and performs a probabilistic record linkage using the Dice coecient similarity measure. As garbled circuits are known for their expensive computations, we propose new approaches that reduce the computation overhead needed, to achieve a given level of privacy. We built a scalable record linkage system using garbled circuits, that could be deployed in a distributed computation environment like the cloud, and evaluated its security and performance. One of the performance issues for linking large datasets is the amount of secure computation to compare every pair of records across the linked datasets to nd all possible record matches. To reduce the amount of computations a method, known as blocking, is used to lter out as much as possible of the record pairs that will not match, and limit the comparison to a subset of the record pairs (called can- didate pairs) that possibly match. Most of the current blocking methods either require the parties to share blocking keys (called blocks identiers), extracted from the domain of some record attributes (termed blocking variables), or share reference data points to group their records around these points using some similarity measures. Though these methods reduce the computation substantially, they leak too much information about the records within each block. Toward this end, we proposed a novel privacy preserving approximate blocking scheme that allows parties to generate the list of candidate pairs with high accuracy, while protecting the privacy of the records in each block. Our scheme is congurable such that the level of performance and accuracy could be achieved according to the required level of privacy. We analyzed the accuracy and privacy of our scheme, implemented a prototype of the scheme, and experimentally evaluated its accuracy and performance against dierent levels of privacy

    Autonomous Sweet Pepper Harvesting for Protected Cropping Systems

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    In this letter, we present a new robotic harvester (Harvey) that can autonomously harvest sweet pepper in protected cropping environments. Our approach combines effective vision algorithms with a novel end-effector design to enable successful harvesting of sweet peppers. Initial field trials in protected cropping environments, with two cultivar, demonstrate the efficacy of this approach achieving a 46% success rate for unmodified crop, and 58% for modified crop. Furthermore, for the more favourable cultivar we were also able to detach 90% of sweet peppers, indicating that improvements in the grasping success rate would result in greatly improved harvesting performance
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