The Internet of Things (IoT) is the ability to provide everyday devices with a way of identification and another way for communication with each other. The spectrum of IoT application domains is very large including smart homes, smart cities, wearables, e-health, etc. Consequently, tens and even hundreds of billions of devices will be connected. Such devices will have smart capabilities to collect, analyze and even make decisions without any human interaction. Security is a supreme requirement in such circumstances, and in particular authentication is of high interest given the damage that could happen from a malicious unauthenticated device in an IoT system. This paper gives a near complete and up-to-date view of the IoT authentication field. It provides a summary of a large range of authentication protocols proposed in the literature. Using a multi-criteria classification previously introduced in our work, it compares and evaluates the proposed authentication protocols, showing their strengths and weaknesses, which constitutes a fundamental first step for researchers and developers addressing this domain.

A Survey of Internet of Things (IoT) Authentication Schemes

Off-line signature verification based on grey level information using texture features

Wireless sensor network (WSN) is an indispensible part of Internet of Things that has been applied in many fields to monitor environments and collect data from surroundings. However, WSNs are highly susceptible to attacks due to its unique characteristics: large-scale, self-organization, dynamic topology, and constrained resources. A number of systems have been proposed to effectively detect varieties of attacks in WSNs. However, most previous surveys on WSN attacks focus on detection methods for only one or two types of attacks and lack detailed performance analysis. Additionally, the literature lacks comprehensive studies on security-related data (in short security data) collection in WSNs. In this paper, we first provide an overview of WSNs and classify the attacks in WSNs based on protocol stack layers. For the purpose of WSN security measurement, we then research attack detection methods of eleven mainstream attacks. We extract security data that play an important role for detecting security anomaly toward security measurement. We further elaborate the advantages and disadvantages of the existing detection methods based on a number of evaluation criteria. Finally, we highlight a number of open problems in this paper field based on our thorough survey and conclude this paper with possible future research directions.

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Data Collection for Security Measurement in Wireless Sensor Networks: A Survey

Due to the explosion of available information on the Internet, the need for effective means of accessing and processing them has become vital for everyone. Recommender systems have been developed to help users to find what they may be interested in and business owners to sell their products more efficiently. They have found much attention in both academia and industry. A recommender algorithm takes into account user–item interactions, i.e., rating (or purchase) history of users on items, and their contextual information, if available. It then provides a list of potential items for each target user, such that the user is likely to positively rate (or purchase) them. In this paper, we review evaluation metrics used to assess performance of recommendation algorithms. We also survey a number of classical and modern recommendation algorithms and compare their performance in terms of different evaluation metrics on five benchmark datasets. Our experiments show that there is no golden recommendation algorithm showing the best performance in all evaluation metrics. We also find large variability across the datasets. This indicates that one should carefully consider the evaluation criteria in choosing a recommendation algorithm for a particular application.

Evaluating Collaborative Filtering Recommender Algorithms: A Survey

We present Fiberio, a rear-projected multitouch table that identifies users biometrically based on their fingerprints during each touch interaction. Fiberio accomplishes this using a new type of screen material: a large fiber optic plate. The plate diffuses light on transmission, thereby allowing it to act as projection surface. At the same time, the plate reflects light specularly, which produces the contrast required for fingerprint sensing. In addition to offering all the functionality known from traditional diffused illumination systems, Fiberio is the first interactive tabletop system that authenticates users during touch interaction-unobtrusively and securely using the biometric features of fingerprints, which eliminates the need for users to carry any identification tokens.

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Fiberio: a touchscreen that senses fingerprints

In wormhole attacks, attackers create a low-latency link between two points in the network. This can be achieved by either compromising two or more sensor nodes of the network or adding a new set of mali-cious nodes to the network. Once the link is established, the attacker collects data packets on one end of the link, sends the data packets using the low-latency link and replays them at the other end. Wormhole attacks result in alterations in network data flow thereby deceiving the base station. Although implementing a wormhole attack is relatively simple, detecting it is not a trivial task as the replayed information is usually valid. This paper focuses on wormhole attacks and presents the state-of-the-art in wormhole attack detection in wireless sensor networks. The existing wormhole detection protocols are presented in detail and, based on the existing research, the open research areas and future research directions in wormhole attack detection are provided.

A Survey of Wormhole-based Attacks and their Countermeasures in Wireless Sensor Networks

Recommender systems attempt to suggest information that is of potential interest to users helping them to quickly find information relevant to them. In addition to historical user–item interaction data, such as users’ ratings on items, social recommendation methods use social relationships between users to improve the accuracy of recommendations. However, the available social relationships are often extremely sparse. Therefore, incorporating implicit relationships into the recommendation process can be effective to improve the performance of social recommender systems, especially for those users whose explicit relationships are insufficient to make accurate recommendations. The existing approaches have not considered reliability of the implicit relationships. In this paper, a social recommender system is proposed based on reliable implicit relationships. To this end, Dempster–Shafer theory is used as a powerful mathematical tool to calculate the implicit relationships. Moreover, a new measure is introduced to evaluate the reliability of predictions, where unreliable predictions are recalculated using a neighborhood improvement mechanism. This mechanism uses a confidence measure between the users to identify ineffective users in the neighborhood set of a target user. Finally, new reliable ratings are calculated by removing the identified ineffective neighbors. Extensive experiments are conducted on three well-known datasets, and the results demonstrate that our approach achieves superior performance to the state-of-the-art recommendation methods.

A social recommender system based on reliable implicit relationships

Recommender systems are techniques to make personalized recommendations of items to users. In e-commerce sites and online sharing communities, providing high quality recommendations is an important issue which can help the users to make effective decisions to select a set of items. Collaborative filtering is an important type of the recommender systems that produces user specific recommendations of the items based on the patterns of ratings or usage (e.g. purchases). However, the quality of predicted ratings and neighbor selection for the users are important problems in the recommender systems. Selecting suitable neighbors set for the users leads to improve the accuracy of ratings prediction in recommendation process. In this paper, a novel social recommendation method is proposed which is based on an adaptive neighbor selection mechanism. In the proposed method first of all, initial neighbors set of the users is calculated using clustering algorithm. In this step, the combination of historical ratings and social information between the users are used to form initial neighbors set for the users. Then, these neighbor sets are used to predict initial ratings of the unseen items. Moreover, the quality of the initial predicted ratings is evaluated using a reliability measure which is based on the historical ratings and social information between the users. Then, a confidence model is proposed to remove useless users from the initial neighbors of the users and form a new adapted neighbors set for the users. Finally, new ratings of the unseen items are predicted using the new adapted neighbors set of the users and the t o p _ N interested items are recommended to the active user. Experimental results on three real-world datasets show that the proposed method significantly outperforms several state-of-the-art recommendation methods.

A social recommendation method based on an adaptive neighbor selection mechanism

A different approach to off-line handwritten signature verification using the optimal dynamic time warping algorithm

Recommender systems are one of the information filtering tools which can be employed to find interest items of users. Collaborative filtering is one of the recommendation methods to provide suggestions for target users based on the ratings of like-interest users. This method suffers from some shortcomings such as cold start problem leading to reduce the performance of recommender system in predicting unseen items. In this paper, we propose a hybrid recommendation method based on profile expansion technique to alleviate cold start problem in recommender systems. For this purpose, we take into consideration user’s demographic data (e.g. age, gender, and occupation) beside user’s rating data in order to enrich the neighborhood set of users. Specifically, two different strategies are used to enrich the rating profile of users by adding some additional ratings to them. The proposed rating profile expansion mechanism has a significant effect on the performance improvement of recommender systems especially when they are facing with cold start problem. The reason behind this claim is that the proposed mechanism makes a denser user-item rating matrix than the original one by adding some additional ratings to it. Obviously, providing a rating profile with further ratings for the target user leads to alleviate cold start problem in recommender systems. The expanded rating profiles are used to calculate similarity values between users and predict unseen items. The results of experiments demonstrate that the proposed method can achieve better performance than the other recommendation methods in terms of accuracy and rate coverage measures.

Majid Meghdadi

Papers

A Survey of Wormhole-based Attacks and their Countermeasures in Wireless Sensor Networks

A social recommender system based on reliable implicit relationships

A social recommendation method based on an adaptive neighbor selection mechanism

A different approach to off-line handwritten signature verification using the optimal dynamic time warping algorithm

A hybrid recommendation system based on profile expansion technique to alleviate cold start problem