Observing CoAP groups efficiently

With the rapid expansion of Internet of Things (IoT), Constrained Application Protocol (CoAP) is developed to enable those devices with small memory, constrained computing power and limited ability to communicate with other nodes in the network. Meanwhile, group communication is very useful for managing and controlling a set of homogeneous devices in many IoT scenarios. Thus, many scholars are devoted to expanding CoAP to enable group communication. Furthermore, because CoAP is widely applicated in transportation, health care, industrial and many other areas, the security and consistency of data is of great importance. In this paper, we adopt Communicating Sequential Processes (CSP) to model group communication CoAP, and we use model checker Process Analysis Toolkit (PAT) to verify six properties of our model, including deadlock freedom, divergence freedom, data reachability, data leakage, client faking and entity manager faking. The verification results show that the original architecture has the security risk of data leakage. So we enhance it by adding message authentication code in the process. In the light of the new verification results, it can be found that we succeed in eliminating the possibility of data leakage.KeywordsGroup communicationCoAPCSPModelingVerification

The Internet of Things (IoT) is expanding rapidly to new domains in which embedded devices play a key role and gradually outnumber traditionally-connected devices. These devices are often constrained in their resources and are thus unable to run standard Internet protocols. The Constrained Application Protocol (CoAP) is a new alternative standard protocol that implements the same principals as the Hypertext Transfer Protocol (HTTP), but is tailored towards constrained devices. In many IoT application domains, devices need to be addressed in groups in addition to being addressable individually. Two main approaches are currently being proposed in the IoT community for CoAP-based group communication. The main difference between the two approaches lies in the underlying communication type: multicast versus unicast. In this article, we experimentally evaluate those two approaches using two wireless sensor testbeds and under different test conditions. We highlight the pros and cons of each of them and propose combining these approaches in a hybrid solution to better suit certain use case requirements. Additionally, we provide a solution for multicast-based group membership management using CoAP.

The energy resources of Machine-to-Machine (M2M) devices need to last as much as possible. Data aggregation is a suitable solution to prolong the network lifetime, since it allows the devices to reduce the amount of data traffic. In M2M systems, the M2M platform and the Constrained Application Protocol (CoAP) enable multiple entities to send concurrent data-requests to the same capillary network. For example, in a Smart Metering scenario, there are devices measuring the electricity consumption of an entire building. The supplier company requests all devices to send the data updates every 1800 seconds (i.e., 30 minutes). On the other hand, a resident requests his/her devices to communicate every 600 seconds (i.e., 10 minutes). These concurrent data-requests create heterogeneous groups over the same capillary network, since each group might be able to execute different in-network functions and to have a unique temporal-frequency of communication. However, the traditional data aggregation solutions designed for periodic monitoring assume the execution of a single static data-request during all network lifetime. This makes the traditional data aggregation solutions not suitable for M2M environments. To fill this gap, this paper presents Data Aggregation for Multiple Groups (DAMiG), which is designed to provide Data Aggregation for heterogeneous and concurrent sets of CoAP data-requests. DAMiG explores the group communication periodicity to perform internal and external-group traffic aggregation. To achieve that, DAMiG computes a suitable aggregation structure and applies statistical and merger aggregation functions along the path. DAMiG is able to reduce the energy consumption in scenarios with single or several concurrent CoAP data-requests. Moreover, the selection of internal and external-group paths takes into account the residual energy of the nodes, avoiding the paths with low residual energy.

Internet of Things (IoT) is a prominent paradigm applied to several areas ranging from medicine to industrial networks. It aims at connecting to the Internet of million of daily used objects. Important challenges in this area consist in to propose mechanisms and protocols that meet security, device interoperability, quality of service and energy-efficiency requirements. Particularly, the Message Queue Telemetry Transport (MQTT) protocol has been prospected in order to provide efficient communication at the application layer for the IoT. This survey aims to present the fundamentals, tools and future directions related to MQTT protocol and its variation tailored for sensor networks, called MQTT-SN. We discuss such protocols comparing to other current IoT application layer protocols, such as Constrained Application Protocol (CoAP). Additionally, we present tools so as to support practical experimentation and simulation. Particularly, we carry out pactical experiments to observe the communication delay between MQTT and CoAP. Finally, the open issues and challenges in this area are examined.

The need for embedded devices to be able to exchange information with each other and with data centers is essential for the advent of the Internet of Things (IoT). Several existing communication protocols are designed for small devices including the message-queue telemetry transport (MQTT) protocol or the constrained application protocol (CoAP). However, most of the existing implementations are convenient for computers or smart phones but do not consider the strict constraints and limitations with regard resource usage, portability and configuration. In this paper, we report on an industrial research and development project which focuses on the design, implementation, testing and deployment of a MQTT module. The goal of this project is to develop this module for platforms having minimal RAM, flash code memory and processing power. This software module should be fully compliant with the MQTT protocol specification, portable, and inter-operable with other software stacks. In this paper, we present our approach based on abstraction layers to the design of the MQTT module and we discuss the compliance of the implementation with the requirements set including the MISRA static analysis requirements.

In this paper we explore the security challenges of the IoT industry with focus on standardized communication protocols. We provide implementation details for the security levels mandated by the Constrained Application Protocol and see how these reflect in Message Queuing Telemetry Transport protocol. Finally we conclude our analysis emphasizing the necessity of anonymization and decentralized authentication.

In the current Internet of Things (IoT) all sorts of devices and objects with diverse capabilities are being connected to the Internet and the Web. Consequently, new lightweight network protocols are also being developed to connect resource-constrained devices or networks with each other. One of these protocols is the Constrained Application Protocol, which provides a REST architecture to resource and network-constrained devices. Besides the RESTful client-server paradigm, CoAP supports a publish-subscribe model thanks to its Observe extension which mimics some of MQTT's functionalities. However, this extension has some limitations in the subscription mechanism. Hence, this paper proposes several enhancements that define new CoAP options and response codes for such mechanisms. Furthermore, a theoretical comparison of the current CoAP capabilities against the new possibilities is also provided. For that, an specific use case is proposed, and a comparison in terms of the overhead required to exchange payloads and to subscribe to state change notifications on resources.

Open authorization (OAuth) is an open protocol, which allows secure authorization in a simple and standardized way from third-party applications accessing online services, based on the representational state transfer (REST) web architecture. OAuth has been designed to provide an authorization layer, typically on top of a secure transport layer such as HTTPS. The Internet of Things (IoTs) refers to the interconnection of billions of resource-constrained devices, denoted as smart objects, in an Internet-like structure. Smart objects have limited processing/memory capabilities and operate in challenging environments, such as low-power and lossy networks. IP has been foreseen as the standard communication protocol for smart object interoperability. The Internet engineering task force constrained RESTful environments working group has defined the constrained application protocol (CoAP) as a generic web protocol for RESTful-constrained environments, targeting machine-to-machine applications, which maps to HTTP for integration with the existing web. In this paper, we propose an architecture targeting HTTP/CoAP services to provide an authorization framework, which can be integrated by invoking an external oauth-based authorization service (OAS). The overall architecture is denoted as IoT-OAS. We also present an overview of significant IoT application scenarios. The IoT-OAS architecture is meant to be flexible, highly configurable, and easy to integrate with existing services. Among the advantages achieved by delegating the authorization functionality, IoT scenarios benefit by: 1) lower processing load with respect to solutions, where access control is implemented on the smart object; 2) fine-grained (remote) customization of access policies; and 3) scalability, without the need to operate directly on the device.

For complex missions that are away from Earth’s resources, there is an unmet need for more autonomous operations with minimal Earth contact. Dynamic, delay and disruption tolerant communications and networking topologies at various Quality of Service levels are needed to meet future mission requirements, which may include multiple spacecraft flying in formation and coordinating among themselves. Additionally, secure proximity- and autonomous-communication among various types of space vehicles are needed to share rich, near real-time streams of information. Along with scalability and extensibility, cybersecurity is a crucial requirement for autonomous communications in space. taraCoAP is based on the terrestrial standard Constrained Application Protocol (CoAP) and along with its Cyber-Physical Autonomous Asset Observation and Management extension provides delay and disruption tolerant, autonomous communication among swarms or clusters of spacecraft to implement complex and time-varying networks to coordinate, collaborate and share rich streams of information. Efficient and mission-configurable, taraCoAP runs over the Bundle Protocol, utilizing an advanced Bundle Protocol Security Cipher Suite for secure, interoperable, cross-domain communications.

The fast growth of the Internet of Things (IoT) has made this technology one of the most promising paradigms of recent years. Wireless Sensor Networks (WSNs) are one of the most important challenges of the Internet of things. These networks are made up of devices with limited processing power, memory, and energy. The constrained nature of WSNs makes it necessary to have specific restricted protocols to work in these environments. In this paper, we present an energy consumption and network traffic study of the main IoT application layer protocols, the Constrained Application Protocol (CoAP), and the version of Message Queue Telemetry Transport (MQTT) for sensor networks (MQTT_SN). The simulations presented evaluate the performance of these protocols with different network configurations.

The Internet of Things (IoT) concept refers to the usage of standard Internet protocols to allow for human-to-thing and thing-to-thing communication. The security needs for IoT systems are well- recognized and many standardization steps to provide security have been taken, for example, the specification of Constrained Application Protocol (CoAP) secured with Datagram Transport Layer Security (DTLS). However, security challenges still exist, not only because there are some use cases that lack a suitable solution, but also because many IoT devices and systems have been designed and deployed with very limited security capabilities. In this document, we first discuss the various stages in the lifecycle of a thing. Next, we document the security threats to a thing and the challenges that one might face to protect against these threats. Lastly, we discuss the next steps needed to facilitate the deployment of secure IoT systems. This document can be used by implementors and authors of IoT specifications as a reference for details about security considerations while documenting their specific security challenges, threat models, and mitigations. This document is a product of the IRTF Thing-to-Thing Research Group (T2TRG).

In recent years, networked sensors are finding use in a variety of different applications ranging from temperature monitoring to battlefield strategy planning. Advances in fabrication techniques have led to the development of sensor-actuator devices called MEMS. It has now become possible to move software closer to where the “action” is, i.e. the sensors themselves. These sensor devices typically have a micro-controller, instruction and data memory, a radio module for wireless communication and an operating system. These devices are severely resource constrained in terms of memory, processing power and energy, since most of these devices are battery driven. A sensor network consists of a number of sensors spread across a geographical area. Each sensor has wireless communication capability and sufficient intelligence for signal processing and networking of the data. In this paper, we discuss a mechanism to achieve prioritized task scheduling in TinyOS. We investigate into the details of how the task scheduling is currently done in TinyOS and the adverse effects that this could cause. We show use-cases where certain ”important” tasks could be given less preference when compared to other ”notso-important” tasks. We propose a new mechanism at the programming model level to introduce the concept of priority for a task and explain how the scheduling module has to be changed to enforce this priority scheme. Finally, we show empirical results to justify our solution.

In the current Internet of things era, all companies shifted from paper-based data to the electronic format. Although this shift increased the efficiency of data processing, it has security drawbacks. Healthcare databases are a precious target for attackers because they facilitate identity theft and cybercrime. This paper presents an approach for database damage assessment for healthcare systems. Inspired by the current behavior of COVID-19 infections, our approach views the damage assessment problem the same way. The malicious transactions will be viewed as if they are COVID-19 viruses, taken from infection onward. The challenge of this research is to discover the infected transactions in a minimal time. The proposed parallel algorithm is based on the transaction dependency paradigm, with a time complexity O((M+NQ+N^3)/L) (M = total number of transactions under scrutiny, N = number of malicious and affected transactions in the testing list, Q = time for dependency check, and L = number of threads used). The memory complexity of the algorithm is O(N+KL) (N = number of malicious and affected transactions, K = number of transactions in one area handled by one thread, and L = number of threads). Since the damage assessment time is directly proportional to the denial-of-service time, the proposed algorithm provides a minimized execution time. Our algorithm is a novel approach that outperforms other existing algorithms in this domain in terms of both time and memory, working up to four times faster in terms of time and with 120,000 fewer bytes in terms of memory.

Permeability Surface Area Product Using Perfusion Computed Tomography Is a Valuable Prognostic Factor in Glioblastomas Treated with Radiotherapy Plus Concomitant and Adjuvant Temozolomide

Since the Internet of Things (IoT) will be entwined with everything we use in our daily life, the consequence of security flaws escalates. Smart objects will govern most of the home appliances and car engines yielding potential disaster scenarios. In this context, successful attacks could lead to chaos and scary scenarios (www.darkreading.com). Unprotected personal information may expose sensitive and embarrassing data to the public and attacks may threaten not only our computers and smart devices, but our intimacy and perhaps our lives too. Because persons and objects will be bonded with each other, user consent becomes critical. Therefore, thing, object, and user Identity will be the focus of future IoT security solutions, yielding a Trust, Security, and Privacy (TSP) paradigm, which may constitute the Achilles' heel of IoT. While security issues are quite straightforward, mainly from background knowledge, privacy issues are far more complex. Privacy constitutes a rather challenging task, even for the m...