Long-range wide-area network (LoRaWAN) is a low-power wide-area network (LP-WAN) protocol developed for low-bandwidth, battery-operated long-range sensors. However, the LoRaWAN specification has several security issues and utilizes software cryptography, which is not energy efficient. Our proposed solution combines a modified LoRaWAN protocol with a hardware-based cryptographic coprocessor that includes secure on-chip key storage for encryption, decryption, and digital signature creation. This design reduces the energy utilization of the wireless nodes while addressing several of the LoRaWAN threat surfaces. This article provides a security analysis of the reduced threat surfaces and demonstrates the improved energy efficiency of the LoRaWAN nodes with the integrated solution.

Outsourcing storage and computation to clouds is popular but also raises security concerns. Most existing solutions mainly focus on an honest-but-curious cloud server, while security designs against a malicious server have not drawn enough attention. Although there are a few works addressing the issue of verifiable designs that enable the data owner to verify the integrity of search results. Unfortunately, these verification schemes are not efficient and or applicable from one scenario to another. Motivated by this, in this paper, we propose a publicly verifiable search framework for outsourced encrypted data based on blockchain. In our framework, we store the encrypted index in a decentralized blockchain (Ethereum) while outsourcing the corresponding encrypted data to the cloud or Interplanetary File System (IPFS). Thus, once a user is authorized, he/she can get the query results and check the query integrity efficiently by the designed smart contract anytime without data owner being online. Besides, to guarantee the privacy of the data user in the Ethereum, we construct a stealth authorization scheme to achieve access authorization delivery. The security analysis and performance evaluation show that the proposed scheme is secure and practical for verification of encrypted data.

Although the Internet has become a hub around which every aspect of our lives-from commerce to leisurely activities-is centered, many around the world are not able to freely access information over the Internet. Some governments censor what the people can and cannot see. In this paper, regardless of the socio-political view points, we focus on the design of anti-censorship technology that can be implemented on the side of the information purveyors. The primary objective is to develop a framework for combating censorship. Our approach aims to make it too expensive and impractical for the adversary to censor Web sites. In particular, we propose the use of Mobile IPv6 to form a moving target defense strategy, where the Web servers logically behave as if they are the mobile nodes (without actually moving). The potential efficacy of this framework is modeled analytically. Probabilistic models are used to derive important metrics and parameters. One key factor termed swarming ratio enables hosting sites to reason about the amount of resources needed to force the adversary's costs over practical limits. This model is used to guide the performance goals and architectural setup of the prototype implementation (modifications are made on the server-side software and Kernel without changing the standard Mobile IPv6 protocol). Hence, the solution can be utilized without any changes to the existing network infrastructure. Furthermore, we introduce a novel, credit-based accounting strategy for grouping of users to drastically shift resource requirements in our favor. Lab-based tests are used to measure performance overheads, and based on the findings, targeted optimizations are performed to consider practical deployment scenarios. The end result is a solution that may also be combined with existing anti-censorship methods (that are end-user-based and/or assisted by friendly network assets) to form a robust anti-censorship solution.

In this paper, we introduce MVPN, a framework for building secure Virtual Private Networks (VPNs) with a novel Mobile IPv6 based Moving Target Defense strategy. Our approach aids in combating remote attacks against a VPN server. By eliminating the static address of the server, we make it difficult for an attacker to find the server. The server''s address is randomly changed at a certain interval creating a moving target. At the same time, authenticated clients are updated through the use of the Binding Update procedure (standard Mobile IPv6 protocol). One key strength of this approach lies in the fact that the clients do not need to make any changes or use special software. Our testbed experiments show low packet-loss rates that may occur due to the handoff delay.

In wireless mobile ad hoc networks, many important communications are based on the global broadcast that relies on a reliable 1-hop broadcasting in which a message from the source node is guaranteed to be delivered to all nodes within the source node's transmission range. Recently, a noble algorithm called CSMA/CN is proposed that utilizes collision notification to improve the network throughput. This paper presents an improved MAC protocol called ROB/CN (Reliable 1-Hop Broadcast Using Collision Notification) that achieves a guaranteed reliable 1-hop broadcast using CSMA/CN. In most previously proposed algorithms, if a transmission undergoes a collision, then the transmission should be restarted all over again, whereas in ROB/CN, the retransmission is not necessary if the collision is caused by only a small number of transmissions. Simulation results show the effectiveness of the proposed algorithm.

In this paper, a novel three-party quantum authenticated key distribution with a partially trusted third party protocol is proposed. Unlike most classical cryptography, the security of the protocol does not rely on the amount of computations required to find the encryption key, but on physical properties of the transmission medium (i.e., quantum mechanical properties). The session key shared between participants is concealed from the trusted third party while the participants trust the third party regarding the authentication part. Thus, the proposed system will be preferable for network systems in/between institutions, which deal with highly sensitive information (e.g., military bases, research facilities, hospitals).

In recent years, many quantum cryptographic schemes have been proposed. However, it seems that there are many technical difficulties to realize them (except Quantum Key Distributions) as practical applications. In this paper, we propose a bank transfer (i.e., funds or Electronic Funds Transfer) system utilizing both classical and quantum cryptography to provide theoretically unbreakable security. This system can be realized using current technologies (e.g., linear polarizers and Faraday rotators) and requires no additional authentication and no key distribution scheme. However, a trusted third party must keep all member banks' private keys for encryption, authentication and also for functions to generate classical digital signatures.

When it became known that quantum computers could break the RSA (named for its creators - Rivest, Shamir, and Adleman) encryption algorithm within a polynomial-time, quantum cryptography began to be actively studied. Other classical cryptographic algorithms are only secure when malicious users do not have computational power enough to break security within a practical amount of time. Recently, many quantum authentication protocols sharing quantum entangled particles between communicators have been proposed, providing unconditional security. An issue caused by sharing quantum entangled particles is that it may not be simple to apply these protocols to authenticate a specific user in a group of many users. We propose an authentication protocol using quantum superposition states instead of quantum entangled particles. Our protocol can be implemented with the current technologies we introduce in this paper.

Multicomputer systems achieve high performance by utilizing a number of computing nodes. Recently, by achieving significant reductions in communication delay, the three-dimensional (3D) torus has emerged as a new candidate interconnection topology for message-passing multicomputer systems. In this paper, we propose an efficient processor allocation scheme-scan search scheme-for the 3D torus based on a first-fit approach. The scan search scheme minimizes the average allocation time for an incoming task by effectively manipulating the 3D information on a torus as 2D information using a data structure called the CST (Coverage Status Table). Comprehensive computer simulation reveals that the allocation time of the scan search scheme is always smaller than that of the earlier scheme based on a best-fit approach. The difference gets larger as the input load increases, and it is as much a factor of 3 for high load. To investigate the performance of the proposed scheme in different scheduling environments, we also consider a non-FCFS scheduling policy along with the typical FCFS policy. The allocation time complexity of the scan search scheme is O(LW/sup 2/H/sup 2/). This is significantly smaller than that of the existing scheme which is O(L/sup 4/W/sup 4/H/sup 4/). Here, L, W, and H represent the length, width, and height of 3D torus, respectively.

Efficient allocation of processors to incoming tasks in parallel computer systems is very important for achieving the desired high performance. It requires recognizing the free available processors with minimum overhead. In this paper, we present an efficient task allocation scheme for 2D mesh architectures. By employing a new approach for searching the mesh, our scheme can find the available submesh without scanning the entire mesh, unlike earlier designs. Comprehensive computer simulation reveals that the average allocation time and waiting delay are much smaller than earlier schemes of comparable performances, irrespective of the size of meshes and distribution of the shape of the incoming tasks.

Efficient allocation of proper size submeshes to incoming tasks in two-dimensional (2D) mesh-connected processors is very important for achieving the desired high performance. It also needs to guarantee the recognition of the free submeshes with minimum overhead. In this paper we present an efficient task allocation scheme for 2D meshes. By employing a new approach for searching the array, our scheme can find the available submesh without the scanning of the entire 2D array unlike earlier designs. As a result, our scheme can significantly reduce the task allocation time. Comprehensive computer simulation reveals that the average allocation time and waiting delay are much smaller than earlier schemes irrespective of the size of meshes. The hardware overhead is comparable to other schemes.