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Motifs have critical impacts on the behavioral and structural characteristics of RNA sequences. Understanding and predicting the functionalities and interactions of an RNA sequence requires discovering and identifying its motifs. Due to the importance of motif discovery in bioinformatics, a significant corpus of techniques and algorithms have been proposed, each of which has various advantages and limitations and hence, are suitable for specific applications. To understand these techniques and algorithms, compare them, and choose the most suitable one for a particular application scenario, it is crucial to have a clear understanding of the different vital aspects that characterize these algorithms. The lack of such a framework to study these aspects is a serious existing challenge in the literature that needs further investigation. In this paper, we propose a taxonomy and a framework to address this issue. We define the concept of motif discovery process and three aspects that characterize such a process, which are motif type, discovery technique, and application. We then study the literature and classify the existing approaches along with these aspects. This will give the reader a broader view and more precise understanding of what these techniques and algorithms do, how they do it, and what is the most suitable application for each of them. We then present the possible gaps and challenges foreseen to be the future directions of the area. [ABSTRACT FROM AUTHOR]

Summary: Internet of Things (IoT) is a newly emerged paradigm where multiple embedded devices, known as things, are connected via the Internet to collect, share, and analyze data from the environment. In order to overcome the limited storage and processing capacity constraint of IoT devices, it is now possible to integrate them with cloud servers as large resource pools. Such integration, though bringing applicability of IoT in many domains, raises concerns regarding the authentication of these devices while establishing secure communications to cloud servers. Recently, Kumari et al proposed an authentication scheme based on elliptic curve cryptography (ECC) for IoT and cloud servers and claimed that it satisfies all security requirements and is secure against various attacks. In this paper, we first prove that the scheme of Kumari et al is susceptible to various attacks, including the replay attack and stolen‐verifier attack. We then propose a lightweight authentication protocol for secure communication of IoT embedded devices and cloud servers. The proposed scheme is proved to provide essential security requirements such as mutual authentication, device anonymity, and perfect forward secrecy and is robust against security attacks. We also formally verify the security of the proposed protocol using BAN logic and also the Scyther tool. We also evaluate the computation and communication costs of the proposed scheme and demonstrate that the proposed scheme incurs minimum computation and communication overhead, compared to related schemes, making it suitable for IoT environments with low processing and storage capacity. [ABSTRACT FROM AUTHOR]

In recent years, blockchain technology has been used in many fields, including IoT and Smartphones. Since most of these devices are battery constrained and have low processing capabilities, conventional blockchains are not suitable for these types of systems. In this field, critical challenges that need to be addressed are providing security for transactions and power consumption. An available solution to meet the mentioned challenges is TrustChain. Unlike conventional blockchains, TrustChain does not have a single global chain. Instead, each node is responsible for building and maintaining its local chain. With all the benefits, TrustChain is vulnerable to the whitewashing attack and suffers from client vulnerability issues. Moreover, once a fatal error occurs, the recovery time of each TrustChain node is considerably high. In this paper, we propose a solution to address the attacks mentioned above by implementing an authentication system with MongoDB on top of TrustChain. Moreover, we connected TrustChain to the distributed cloud storage to significantly reduce the recovery time of nodes in fatal errors (up to 80%). Finally, we evaluate improved TrustChain with the PoW-based smartphone-oriented blockchains from two aspects of security and power consumption, proving that improved TrustChain does not significantly affect the lifetime of the smartphone battery. Its power consumption is less than mentioned blockchains and is more secure than these systems against main attacks. [ABSTRACT FROM AUTHOR]