Internet of Things (IoT) has been a major research topic for almost a decade now, where physical objects would be interconnected as a result of convergence of various existing technologies. IoT is rapidly developing; however there are uncertainties about its security and privacy which could affect its sustainable development. This paper analyzes the security issues and challenges and provides a well defined security architecture as a confidentiality of the user's privacy and security which could result in its wider adoption by masses.

Internet, a revolutionary invention, is always transforming into some new kind of hardware and software making it unavoidable for anyone. The form of communication that we see now is either human-human or human-device, but the Internet of Things (IoT) promises a great future for the internet where the type of communication is machine-machine (M2M). This paper aims to provide a comprehensive overview of the IoT scenario and reviews its enabling technologies and the sensor networks. Also, it describes a six-layered architecture of IoT and points out the related key challenges.

The holographic dark energy (HDE) is considered to be the most promising candidate of dark energy. Its definition is originally motivated from the entropy-area relation which depends on the theory of gravity under consideration. Recently a new definition of HDE is proposed with the help of quantum corrections to the entropy-area relation in the setup of loop quantum cosmology. Using this new definition, we investigate the model of interacting dark energy and derive its effective equation of state. Finally we establish a correspondence between generalized Chaplygin gas and entropy-corrected holographic dark energy.

A so-called "entropy-corrected holographic dark energy" (ECHDE), was recently proposed to explain the dark energy-dominated universe with the help of quantum corrections to the entropy-area relation in the setup of loop quantum cosmology.Using this new definition, we investigate its thermodynamical features including entropy and energy conservation. We describe the thermodynamical interpretation of the interaction between ECHDE and dark matter in a non-flat universe. We obtain a relation between the interaction term of the dark components and thermal fluctuation. Our study further generalizes the earlier works [M.R. Setare and E.C.Vagenas, Phys. Lett. B 666 (2008) 111; B. Wang et al., Phys. Lett. B 662 (2008)

In this paper, we have constructed a (2 + 1)-dimensional wormhole using inhomogeneous and anisotropic distribution of phantom energy. We have determined the exact form of the equation of state of phantom energy that supports the wormhole structure. Interestingly, this equation of state is linear but variable one and is dependent only on the radial parameter of the model.A typical wormhole is characterized by a tunnel in spacetime connecting two arbitrary spacetime sections. These sections could either belong to the same spacetime or to two different spacetimes. The wormhole geometry arises naturally as a solution of the Einstein field equations [1-3]. Interest in wormhole physics was initiated when Morris and Thorne investigated the wormhole structure and proposed that the material required to construct it has to be exotic, i.e. its (negative) radial pressure and energy density must satisfy the inequality |p| > ρ [4]. They also concluded that this structure could also serve as a time travel machine if it is horizon-free.From the cosmological perspective, a candidate for exotic matter exists namely the phantom energy. Presently it is well-motivated from the observational data that the observable universe is pervaded with the phantom energy, which is characterized by ω = p/ρ < −1 [5, 6]. In recent years, several studies are performed regarding construction of wormholes with the use of phantom energy as an exotic matter [7][8][9][10][11]. The phantom energy is exotic due to its weird and esoteric properties: its energy density increases as the universe expands; its accretion onto all gravitationally bound objects results in disassociating them; it can rip apart the spacetime itself in a finite time which is called the Big Rip.M. Jamil ( ) · M.U. Farooq