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The advancement of 5G communication technology and Internet of Things (IoT) technology has promoted the rapid development of Mobile Edge Computing (MEC). In mobile edge, all IoT devices adopt wireless communication technology. Therefore, it is particularly important to ensure the data security and the privacy of the sender in the process of data transmission. At present, a lot of researchers have proposed a large number of schemes for the authentication of the user in MEC. However, there is no effective and lightweight solution for authentication among users, edge devices and cloud server. In this paper, an efficient three-party authentication and key agreement protocol without using bilinear pairings is designed. The proposed protocol realized authentication among users, edge devices and cloud server, and at the same time, three parties conduct key agreement to obtain a common session key. The security analysis shows that our protocol is secure and meets the security attributes such as session-key security, forward secrecy. The experiment shows that the computation cost is low in this protocol. &nbsp

The rapid development of software-defined networking (SDN) has promoted the idea of programmable data plane (PDP), which opens up unprecedented opportunities for realizing powerful and timely network monitoring. This work explores the advantages of PDP to merge two famous techniques (i.e., the segment routing (SR) and in-band network telemetry (INT)) seamlessly for highly-efficient and adaptive network monitoring. Specifically, by leveraging the protocol-oblivious forwarding (POF), we propose SR-INT, which time-multiplexes the header fields in each packet for INT and SR, and keeps packet length constant end-to-end even though both INT and SR are used. Hence, our proposal can enjoy the benefits of INT and SR, while avoiding the accumulated overheads due to simultaneous usage. We design the packet format of SR-INT, and lay out its packet processing procedure to guarantee that the configuration of SR-INT can be adjusted dynamically to adapt to the requirements of network monitoring. We implement and experimentally demonstrate SR-INT in a POF-based SDN environment. Our results show that SR-INT not only reduces the bandwidth overheads of using SR and INT simultaneously but also simplifies the operations in software-based POF switches.

This paper presents a four-core LC-VCO array in 55 nm CMOS technology. Based on the multi-core VCO array technology and the switched capacitor array technology, the tuning range is expanded, and the phase noise optimization in a wide tuning range is achieved based on the second harmonic noise filtering technology and the Q value degeneration technology, as well as the optimization of the capacitor array switching transistors. The proposed VCO array, occupying a chip area of 1.65 × 1.44 mm2, realizes a measured oscillation frequency range of about 3.7−10 GHz with phase noise of −127.5~−116.08 dBc/Hz at 1 MHz frequency offset, and achieves an output power of 2.69 dBm from a total power consumption of 52.8 mW.

This article will first introduce the conception of complex numbers and then deal with some famous results in complex numbers. In the beginning, we prove the Cauchy-Goursat theorem and calculate the integral along a closed path in a domain on which the given function is analytic. We want to check the relation between a function being analytic, having primitive, and its integral along a closed path equals zero. In conclusion, for a given analytic function on a simply connected domain, integral along any closed path is zero. Using this conclusion, we can prove the residue theorem and the Cauchy integral formula. To prove the existence and uniqueness of Laurent expansion, we first prove the Laurent decomposition by the Cauchy integral formula and Liouville’s theorem. By Laurent’s decomposition theorem, we change the case into dealing with two analytic functions. But one of them is analytic at infinity. The definition of the analytic function is applied to get the result. It’s easy to notice that every singularity of a meromorphic function on a subset of the complex number is isolated. Since meromorphic functions are widely used in variable aspects, it’s important to study isolated singularities. Then by studying the unique Laurent expansion in the neighborhood of the isolated singularity, we can classify isolated singularity.