We will cover IoT security engineering in the following chapters, but for now we would like to emphasize how cross-discipline security engineering is in the real world. One struggles to find it covered in academic curricula outside of a few university computer science programs, network engineering, or dedicated security programs such as SANS. Most security practitioners have strong computer science and networking skills but are less versed in the physical and safety engineering disciplines covered by core engineering curricula. So, the cyber-physical aspects of the IoT face a safety versus security clash of cultures and conundrums:

Because the IoT is concerned with connecting physically engineered and manufactured objects—and thus may be a CPS—this conundrum more than any other comes into play. The IoT device engineer may be well versed in safety issues, but not fully understand the security implications of design decisions. Likewise, skilled security engineers may not understand the physical engineering nuances of a thing to ascertain and characterize its physical-world interactions (in its intended environment) and fix them. In other words, core engineering disciplines typically focus on functional design, creating things to do what we want them to do. Security engineering shifts the view to consider what the thing can do and how one might misuse it in ways the original designer never considered. Malicious hackers depend on this. The refrigeration system engineer never had to consider a cryptographic access control scheme in what was historically a basic thermodynamic system design. Now, designers of connected refrigerators do, because malicious hackers will look for unauthenticated data originating from the refrigerator or attempt to exploit it and pivot to additional nodes in a home network.

Security engineering is maturing as a cross-discipline, fortunately. One can argue that it is more efficient to enlighten a broad range of engineering professionals in baseline security principles than it is to train existing security engineers in all physical engineering subjects. Improving IoT security requires that security engineering tenets and principles be learned and promulgated by the core engineering disciplines in their respective industries. If not, industries will never succeed in responding well to emergent threats. Such a response requires appropriating the right security mitigations at the right time when they are the least expensive to implement (that is, the original design as well as its flexibility and accommodation of future-proofing principles). For example, a thermodynamics process and control engineer designing a power-plant will have tremendous knowledge concerning the physical processes of the control system, safety redundancies, and so on. If she understands security engineering principles, she will be in a much better position to dictate additional sensors, redundant state estimation logic, or redundant actuators based on certain exposures to other networks. In addition, she will be in a much better position to ascertain the sensitivity of certain state variables and timing information that network, host, application, sensor, and actuator security controls should help protect. She can better characterize the cyber-attack and control system interactions that might cause gas pressure and temperature tolerances to be exceeded with a resultant explosion. The traditional network cybersecurity engineer will not have the physical engineering basis on which to orchestrate these design decisions.

Before characterizing today's IoT devices and enterprises, it should be clear how cross-cutting the IoT is across industries. Medical device and biomedical companies, automotive and aircraft manufacturers, the energy industry, even video game makers and broad consumer markets are involved in the IoT. These industries, historically isolated from each other, must learn to collaborate when it comes to securing their devices and infrastructure. Unfortunately, there are some in these industries who believe that most security mitigations need to be developed and deployed uniquely in each industry. This isolated, turf-protecting approach is ill-advised and short-sighted. It has the potential of stifling valuable cross-industry security collaboration, learning, and development of common countermeasures.

IoT security is an equal-opportunity threat environment; the same threats against one industry exist against the others. An attack and compromise of one device today may represent a threat to devices in almost all other industries. A smart light bulb installed in a hospital may be compromised and used to perform various privacy attacks on medical devices. In other words, the cross-industry relationship may be due to intersections in the supply chain or the fact that one industry's IoT implementations were added to another industry's systems. Real-time intelligence as well as lessons learned from attacks against industrial control systems should be leveraged by all industries and tailored to suit. Threat intelligence, defined well by Gartner, is: evidence-based knowledge, including context, mechanisms, indicators, implications and actionable advice, about an existing or emerging menace or hazard to assets that can be used to inform decisions regarding the subject's response to that menace or hazard (http://www.gartner.com/document/2487216).

The discovery, analysis, understanding and sharing of how real-world threats are compromising ever-present vulnerabilities needs to be improved for the IoT. No single industry, government organization, standards body or other entity can assume to be the dominant control of threat intelligence and information sharing. Security is an ecosystem.

As a government standards body, NIST is well aware of this problem. NIST's recently formed CPS Public Working Group represents a cross-industry collaboration of security professionals working to build a framework approach to solving many cyber-physical IoT challenges facing different industries. It is accomplishing this in meta-form through its draft Framework for Cyber-Physical Systems. This framework provides a useful reference frame from which to describe CPS along with their security and physical properties. Industries will be able to leverage the framework to improve and communicate CPS designs and provide a basis on which to develop system-specific security standards. This book will address CPS security in more detail in terms of common patterns that span many industries.

Like the thermodynamics example we provided above, cyber-physical and many IoT systems frequently invoke an intersection of safety and security engineering, two disciplines that have developed on very different evolutionary paths but which possess partially overlapping goals. We will delve more into safety aspects of IoT security engineering later in this volume, but for now we point out an elegantly expressed distinction between safety and security provided by noted academic Dr. Barry Boehm, Axelrod, W. C., Engineering Safe and Secure Software Systems, p.61, Massachussetts, Artech House, 2013. He poignantly but beautifully expressed the relationship as follows:

Thus it is clear that the IoT and IoT security are much more complex than traditional networks, hosts and cybersecurity. Safety-conscious industries such as aircraft manufacturers, regulators, and researchers have evolved highly effective safety engineering approaches and standards because aircraft can harm the world, and the people in it. The aircraft industry today, like the automotive industry, is now playing catch-up with regard to security due to the accelerating growth of network connectivity to their vehicles.

It is a cliché to declare how fast Moore's law is changing our technology-rich world, how connected our devices, social networks, even bodies, cars, and other objects are becoming.

Another useful way to think of the IoT is what happens when the network extends not to the last mile or last inch endpoint, but the last micron where virtual and digital become physical. Whether the network extends to a motor servo controller, temperature sensor, accelerometer, light bulb, stepper motor, washing machine monitor, or pacemaker, the effect is the same; the information sources and sinks allow broad control, monitoring, and useful visibility between our physical and virtual worlds. In the case of the IoT, the physical world is a direct component of the digital information, whether acting as subject or object.

IoT applications are boundless. Volumes could be written today about what is already deployed and what is currently being planned. The following are just a few examples of how we are leveraging the IoT.

Enterprise IoT is also moving forward with the deployment of IoT systems that serve various business purposes. Some industries have matured their concepts of IoT more than others. In the energy industry, for example, the roll-out of advanced metering infrastructures (which include smart meters with wireless communications capabilities) has greatly enhanced the energy use and monitoring capabilities of the utility. Other industries, such as retail, for example, are still trying to determine how to fully leverage new sensors and data in retail establishments to support enhanced marketing capabilities, improved customer satisfaction, and higher sales.

The architecture of IoT enterprise systems is relatively consistent across industries. Given the various technology layers and physical components that comprise an IoT ecosystem, it is good to consider an enterprise IoT implementation as a system-of-systems. The architecting of these systems that provide business value to organizations can be a complex undertaking, as enterprise architects work to design integrated solutions that include edge devices, gateways, applications, transports, cloud services, diverse protocols, and data analytics capabilities.

Indeed, some enterprises may find that they must utilize IoT capabilities typically found in other industries and served by new or unfamiliar technology providers. Consider a typical Fortune 500 company that may own both manufacturing and retail facilities. This company's Chief Information Officer (CIO) may need to consider deploying smart manufacturing systems, including sensors that track industrial equipment health status, robotics that perform various manufacturing functions, as well as sensors that provide data used to optimize the overall manufacturing process. Some of the deployed sensors may even be embedded right in their own products to add additional benefits for their customers.

This same company must also consider how to leverage the IoT to offer enhanced retail experiences to their customers. This may include information transmitted to smart billboards. In the near future, through direct integration with a connected vehicle's infotainment system, customized advertisements to consumers as they pass by a retail establishment will be possible. There are also complex data analytics capabilities required to support these integrations and customizations.

Elaborating on the Fortune 500 company example, the same CIO may also be tasked with managing fleets of connected cars and shipping vehicles, drone systems that support the inspection of critical infrastructure and facilities, agricultural sensors that are embedded into the ground to provide feedback on soil quality, and even sensors embedded in concrete to provide feedback on the curing process at their construction sites. These examples only begin to scratch the surface of the types of connected IoT implementations and deployments we will see by 2020 and beyond.

This complexity introduces challenges to keeping the IoT secure, and ensuring that particular instances of the IoT cannot be used as a pivoting point to attack other enterprise systems and applications. For this, organizations must employ the services of enterprise security architects who can look at the IoT from the big picture perspective. Security architects will need to be critically involved early in the design process to establish security requirements that must be tracked and followed through during the development and deployment of the enterprise IoT system. It is much too expensive to attempt to integrate security after the fact. Enterprise security architects will select the infrastructure and backend system components that can easily scale to support not only the massive quantities of IoT-generated data, but also have the ability to make secure, actionable sense of all of that data. The following figure provides a representative view of a generic enterprise IoT system-of-systems, and showcases the IoT's dynamic and diverse nature:

Generically, an IoT deployment can consist of smart sensors, control systems and actuators, web and other cloud services, analytics, reporting, and a host of other components and services that satisfy a variety of business use cases. Note that in the preceding figure, we see energy IoT deployments connected to the cloud along with connected vehicle roadside equipment, healthcare equipment, and environmental monitoring sensors. This is not accidental—as previously discussed, one principal feature of IoT is that anything can be connected to everything, and everything to anything. It is perfectly conceivable that a healthcare biosensor both connects to a hospital's monitoring and data analytics system and simultaneously communicates power consumption data to local and remote energy monitoring equipment and systems.

As enterprise security architects begin to design their systems, they will note that the flexibility associated with today's IoT market affords them significant creative ability, as they bring together many different types of protocols, processors, and sensors to meet business objectives. As designs mature, it will become evident that organizations should consider a revision to their overall enterprise architecture to better meet the scaling needs afforded by the large quantities of data that will be collected. Gartner predicts that we will begin to see a shift in the design of transport networks and data processing centers as the IoT matures:

Source: http://www.gartner.com/newsroom/id/2684616

In other words, unprecedented amounts of data will be moved around in unprecedented ways. Integration points will also play a significant role in an enterprise's IoT adoption strategy. Today's ability to share data across organizational boundaries is large, but dwarfed by the justifications and ability to do so in the near future. Many of the data analytics capabilities that support the IoT will rely on a mix of data captured from sensors as well as data from third parties and independent websites.

Consider the concept of a microgrid. Microgrids are self-contained energy generation and distribution systems that allow owner-operators to be heavily self-sufficient. Microgrid control systems rely on data captured from the edge devices themselves, for example, solar panels or wind turbines, but also require data collected from the Internet. The control system may capture data on energy prices from the local utility through an application programming interface (API) that allows the system to determine the optimal time to generate versus buy (or even sell back) energy from the utility. The same control system may require weather forecast feeds to predict how much energy their solar panel installations will generate during a certain period of time.

Another example of the immense data collection from IoT devices is the anticipated proliferation of Unmanned Aerial Systems (UAS)—or drones—that provide an aerial platform for deploying data-rich airborne sensors. Today, 3D terrain mapping is performed by inexpensive drones that collect high-resolution images and associated metadata (location, camera information, and so on) and transfer them to powerful backend systems for photogrammetric processing and digital model generation. The processing of these datasets is too computationally intensive to perform directly on a drone that faces unavoidable size, weight, and power constraints. It must be done in backend systems and servers. These uses will continue to grow, especially as the countries around the world make progress at safely integrated unmanned aircraft into their national airspace systems.

From a security perspective, it is interesting to examine an enterprise IoT implementation based on the many new points of connection and data types. These integration points can significantly heighten the attack surface of an enterprise; therefore, they must be thoroughly evaluated to understand the threats and most cost-effective mitigations.

Another IoT challenge facing enterprise engineers is the ability to securely automate processes and workflows. One of the greatest strengths of the IoT its emphasis on automating transactions between devices and systems; however, we must ensure that sufficient levels of trust are engineered into the systems supporting those transactions. Not doing so will allow adversaries to leverage the automation processes for their own purposes as scalable attack vectors. Organizations that heavily automate workflows should spend adequate time designing their endpoint hardening strategies and the cryptographic support technologies that are vitally important to enabling device and system trust. This can often include infrastructure build-outs such as Public Key Infrastructure (PKI) that provision authentication, confidentiality, and cryptographic credentials to each endpoint in a transaction to enable confidentiality, integrity, and authentication services.

The things in the IoT

There are so many different types of "things" within the IoT that it becomes difficult to prescribe security recommendations for the development of any one particular thing. To aid in doing this, we must first understand the definition of devices and things. ITU-T Y.2060 prescribes the following definitions:

• Device: A piece of equipment with the mandatory capabilities of communication and the optional capabilities of sensing, actuation, data capture, data storage, and data processing
• Thing: An object of the physical world (physical things) or the information world (virtual things), which is capable of being identified and integrated into communication networks

An intrinsic capability of a thing, as it applies to the IoT, is its capability to communicate. The communication methods and layers, especially as they apply to security, are therefore given special attention in this book. Other aspects, such as data storage, sophisticated processing, and data capture, are not present in all IoT devices, but will be addressed in this book as well.

The definition of a thing is especially interesting as it refers to both physical and virtual devices. In practice, we have seen the concept of virtual things in the context of cloud provider solutions. For example, the Amazon Web Services (AWS) IoT Cloud service includes elements known as thing shadows, virtual representations of physical things. These thing shadows allow the enterprise to track the state of physical things even when network connectivity is disrupted and they are not observably online.

Some common IoT things include smart home appliances, connected vehicles (onboard equipment as well as roadside-mounted units), RFID systems used in inventory and identification systems, wearables, wired and wireless sensor arrays and networks, local and remote gateways (mobile phones, tablets), Unmanned Aircraft Systems (UAS), and a host of typically low-power embedded devices. Next, we decompose common elements of IoT devices.

The IoT device lifecycle

Before delving into the basic constitution of an IoT device, we first need to clarify aspects of the IoT lifecycle. IoT security ultimately depends on the entire lifecycle, therefore this book aims to provide security guidance across most of it. You will see certain terms in this book used to specify different IoT lifecycle phases and the relevant actors in each.

IoT device implementation

This includes all aspects of IoT device design and development. At times, we simply refer to it as implementation. It includes the actual, physical, and logical designers of an IoT device in its manufacturing and patching supply chain. Organizations included in this phase include the following:

• Original Equipment Manufacturer (or just "manufacturer") (OEM): OEMs will typically procure off-the-shelf hardware and firmware and tailor a device with unique physical characteristics, enclosure, and/or applications. They package and distribute the products to end operators.
• Board Support Package (BSP) vendors: This vendor typically provides to the OEM customized or off-the-shelf firmware, APIs, and drivers between the hardware and operating systems.
• Original Design Manufacturers (ODM): ODMs will typically provide custom operating systems and OS APIs to OEMs. They may also include hardware sub-assemblies that OEMs make use of.

IoT service implementation

This phase refers to the service organizations who support IoT deployments through enterprise APIs, gateways, and other architectural commodities. Organizations supporting this phase include the following:

• Cloud service provider (CSP): These organizations typically provide, at a minimum, infrastructure as a service
• OEMs: In some cases, IoT device manufacturers (for example, Samsung) operate and manage their own infrastructure

IoT device and service deployment

This lifecycle phase refers to the end deployment of the IoT devices using IoT infrastructure. IoT deployment typically involves IoT application providers, end service providers, and other businesses. Some of these businesses may operate their own infrastructures (for example, some OEMs), but some make use of existing infrastructure offerings as provided by Amazon AWS, Microsoft Azure, and others. They typically provide service layers on top of what the infrastructure supports.

This book jumps around the three simplified lifecycle categories described above depending on the security topic at hand. Each has an indispensible impact on the end security of the devices and their tailored usage.

The hardware

There are a number of IoT development boards that have become popular for prototyping and provide various levels of functionality. Examples of these boards come from Arduino, Beagle Board, Pinoccio, Rasberry Pi, and CubieBoard, among others. These development boards include microcontrollers (MCUs), which serve as the brains of the device, provide memory, and a number of both digital and analog General Purpose Input/Output (GPIO) pins. These boards can be modularly stacked with other boards to provide communication capabilities, new sensors, actuators, and so on to form a complete IoT device.

There are a number of MCUs on the market today that are well suited for IoT development and included within various development boards. Leading developers of MCUs include ARM, Intel, Broadcom, Atmel, Texas Instruments (TI), Freescale, and Microchip Technology. MCUs are integrated circuits (IC) that contain a processor, Read Only Memory (ROM), and Random Access Memory (RAM). Memory resources are frequently limited in these devices; however, a number of manufacturers are IoT-enabling just about anything by augmenting these microcontrollers with complete network stacks, interfaces, and RF and cellular-type transceivers. All of this horsepower is going into system-on-chip configurations and miniaturized daughter boards (single board computers).

In terms of sensor types in the IoT, the sky is the limit. Examples include temperature sensors, accelerometers, air quality sensors, potentiometers, proximity sensors, moisture sensors, and vibration sensors. These sensors are frequently hardwired into the MCU for local processing, responsive actuation, and/or relay to other systems.

Operating systems

Although some IoT devices do not require an operating system, many utilize real time operating system (RTOS) for process and memory management as well as utility services supporting messaging and other communications. The selection of each RTOS is based on needed performance, security and functional requirements of the product.

The selection of any particular IoT component product needs to be evaluated against the requirements of a particular IoT system. Some organizations may require more elaborate operating systems with additional security features such as separation kernels, high assurance process isolation, information flow control, and/or tightly integrated cryptographic security architectures. In these scenarios, an enterprise security architect should look to procure devices that support high-assurance RTOSes, such as Green Hills IntegrityOS or Lynx Software's LynxOS. Some popular IoT operating systems include TinyOS, Contiki, Mantis, FreeRTOS, BrilloOS, Embedded Linux, ARM's mbedOS, and Snappy Ubuntu Core.

Other critical security attributes pertain to security configuration and the storage of security sensitive parameters. In some instances, configuration settings that are applied to an operating system are lost upon power cycle without battery-backed RAM or some other persistent storage. In many instances, a configuration file is kept within persistent memory to provide the various network and other settings necessary to allow the device to perform its functions and communicate. Of even greater interest is the handling of the root password, other account passwords, and cryptographic keys stored on the devices when the device is power-cycled. Each of these issues has one or more security implications and requires the attention of security engineers.

IoT communications

In most deployments, an IoT device communicates with a gateway that in turn communicates with a controller or a web service. There are many gateway options, some as simple as a mobile device (smart phone) co-located with the IoT endpoint and communicating over an RF protocol such as Bluetooth-LE, ZigBee, or Wi-Fi. Gateways such as this are sometimes called edge gateways. Others may be more centrally located in data centers to support any number of dedicated or proprietary gateway IoT protocols, such as message queuing telemetry transport (MQTT) or representational state transfer (REST) communications. The web service may be provided by the manufacturer of the device, or it may be an enterprise or public cloud service that collects information from the fielded edge devices.

In many situations, the end-to-end connectivity between a fielded IoT device and web service may be provided by a series of field and cloud gateways, each aggregating larger quantities of data from sprawled-out devices. Dell, Intel, and other companies have recently introduced IoT gateways to the market. Companies such as Systech offer multi-protocol gateways that allow for a variety of IoT device types to be connected together, using multiple antennas and receivers. There are also consumer-focused gateways, also called hubs, available in the commercial market, that support smart home communications. The Samsung SmartThings hub (https://www.smartthings.com/) is one example of this.

IoT devices may also communicate horizontally, enabling some powerful interactive features. Enabling connected workflows requires the ability to interface via an API to many diverse IoT product types. Consider the example of the smart home for illustrative purposes. As you wake in the morning, your wearable autonomously transmits the wake-up signal over the Wi-Fi network to subscribing devices. The smart television turns on to your favorite news channel, the window blinds automatically rise, the coffee maker kicks off, the shower starts and your car sets a timer to warm up before you leave your home. All of these interactions are enabled through device-to-device communications and illustrate the immense potential of applying the IoT to business enterprises.

Within an IoT device and its host network, a wide array of protocols may be used to enable message transfer and communication. The selection of the appropriate stack of messaging and communication protocols is dependent upon the use cases and security requirements of any specific system; however, there are common protocols that each serve valuable purposes:

This figure provides a view into some of the better-known protocols that can be implemented by IoT devices to form a complete communications stack.

It is worth noting that at this time, many products' design and security requirements are purely up to the manufacturer due to the infancy of the IoT. In many cases, security professionals may not be included this early in the development phase. Although some organizations may provide guidelines, suggestions and checklists, it is important to note that industry regulations strictly pertaining to IoT devices are almost non-existent. The industry for which the device is intended may have its own requirements for privacy, transport communications, and so on, but they are typically based on existing regulatory or compliance requirements such as HIPAA, PCI, SOX, and others. The industrial IoT will probably lead the way in developing much-needed security standardizations before consumer-oriented organizations. For the time being, early efforts to secure IoT implementation and deployment are akin to stuffing square pegs into round holes. The IoT simply has different needs.

Messaging protocols

At the top of the IoT communication stack live the protocols that support the exchange of formatted message data between two endpoints, typically clients and servers, or client-to-client. Protocols such as the MQTT, the Constrained Application Protocol (CoAP), the Data Distribution Service (DDS), the Advanced Message Queuing Protocol (AMQP), and the Extensible Messaging and Presence Protocol (XMPP) run on top of lower-layer communication protocols and provide the ability for both clients and servers to efficiently agree upon data to exchange. RESTful communications can also be run very effectively within many IoT systems. As of today, REST-based communications and MQTT seem to be leading the way.

(http://www.hivemq.com/blog/how-to-get-started-with-mqtt)

MQTT

MQTT is a publish/subscribe model whereby clients subscribe to topics and maintain an always-on TCP connection to a broker server. As new messages are sent to the broker, they include the topic with the message, allowing the broker to determine which clients should receive the message. Messages are pushed to the clients through the always-on connection.

This neatly supports a variety of communication use cases, wherein sensors MQTT-publish their data to a broker and the broker passes them on to other subscribing systems that have an interest in consuming or further processing the sensor data. Although MQTT is primarily suited for use over TCP-based networks, the MQTT For Sensor Networks (MQTT-SN) specification provides an optimized version of MQTT for use within wireless sensor networks (WSN).

Stanford-Clark and Linh Truong. MQTT For Sensor Networks (MQTT-SN) protocol specification, Version 1.2. International Business Machines (IBM). 2013. URL: http://mqtt.org/new/wp-content/uploads/2009/06/MQTT-SN_spec_v1.2.pdf.

MQTT-SN is well suited for use with battery-operated devices possessing limited processing and storage resources. It allows sensors and actuators to make use of the publish/subscribe model on top of ZigBee and similar RF protocol specifications.

CoAP

CoAP is another IoT messaging protocol, UDP-based, and intended for use in resource-constrained Internet devices such as WSN nodes. It consists of a set of messages that map easily to HTTP: GET, POST, PUT, and DELETE.

Source: http://www.herjulf.se/download/coap-2013-fall.pdf

CoAP device implementations communicate to web servers using specific Uniform Resource Indicators (URIs) to process commands. Examples of CoAP-enabled implementations include smart light switches in which the switch sends a PUT command to change the behavior (state, color) of each light in the system.

XMPP

XMPP is based on Extensible Markup Language (XML) and is an open technology for real-time communications. It evolved from the Jabber Instant Messaging (IM) protocol: http://www.ibm.com/developerworks/library/x-xmppintro/.

XMPP supports the transmission of XML messages over TCP transport, allowing IoT developers to efficiently implement service discovery and service advertisements.

XMPP-IoT is a tailored version of XMPP. Similar to human-to-human communication scenarios, XMPP-IoT communications begin with friend requests: http://www.xmpp-iot.org/basics/being-friends/.

Upon confirmation of a friend request, the two IoT devices are able to communicate with each other regardless of their domains. There also exist parent-child device relationships. Parent nodes within XMPP-IoT offer a degree of security in that they can provide policies dictating whom a particular child node can trust (and hence become friends with). Communication between IoT devices cannot proceed without a confirmed friend request between them.

DDS

DDS is a data bus used for integrating intelligent machines. Like MQTT, it also uses a publish/subscribe model for readers to subscribe to topics of interest.

Source: http://www.slideshare.net/Angelo.Corsaro/applied-opensplice-dds-a-collection-of-use-cases

DDS allows communications to happen in an anonymous and automated fashion, since no relationship between endpoints is required. Additionally, Quality of Service (QoS) mechanisms are built into the protocol. DDS is designed primarily for device-to-device communication and is used in deployment scenarios involving wind farms, medical imaging systems, and asset-tracking systems.

AMQP

AMQP was designed to provide a queuing system in support of server-to-server communications. Applied to the IoT, it allows for both publish/subscribe and point-to-point based communications. AMQP IoT endpoints listen for messages on each queue. AMQP has been deployed in numerous sectors, such as transportation in which vehicle telemetry devices provide data to analytics systems for near-real-time processing.

Gateways

Most of the message specifications discussed so far require the implementation of protocol-specific gateways or other devices to either re-encapsulate the communications over another protocol (for example, if it needs to become IP-routable) or perform protocol translation. The different ways of fusing such protocols can have enormous security implications, potentially introducing new attack surfaces into an enterprise. Protocol limitations, configuration, and stacking options must be taken into account during the design of the enterprise architecture. Threat modeling exercises by appropriately qualified protocol security engineers can help in the process.

Transport protocols

The Internet was designed to operate reliably using the Transmission Control Protocol (TCP), which facilitates the acknowledgement of TCP segments transmitted across a network. TCP is the protocol of choice for today's web-based communications as the underlying, reliable transport. Some IoT products have been designed to operate using TCP (for example, those products robust enough to employ a full TCP/IP stack that can speak HTTP or MQTT over a secure (TLS) connection). TCP is frequently unsuitable for use in constrained network environments suffering from high latency or limited bandwidth.

The User Datagram Protocol (UDP) provides a useful alternative, however. UDP provides a lightweight transport mechanism for connectionless communications (unlike session-based TCP). Many highly constrained IoT sensor devices support UDP. For example, MQTT-SN is a tailored version of MQTT that works with UDP. Other protocols, such as CoAP, are also designed to work well with UDP. There is even an alternative TLS design called Datagram TLS (DTLS) intended for products that implement UDP-based transport.

Network protocols

IPv4 and IPv6 both play a role at various points within many IoT systems. Tailored protocol stacks such as IPv6 over Low Power Wireless Personal Area Networks (6LoWPAN) support the use of IPv6 within network-constrained environments common to many IoT devices. 6LoWPan supports wireless Internet connectivity at lower data rates to accommodate highly constrained device form factors: http://projets-gmi.univ-avignon.fr/projets//proj1112/M1/p09/doc/6LoWPAN_overview.pdf.

6LoWPAN builds upon the 802.15.4 -Low Rate Wireless Personal Area Networks (LRWPAN) specification to create an adaptation layer that supports IPv6. The adaptation layer provides features that include IPv6 with UDP header compression and support for fragmentation, allowing constrained sensors, for example, to be used in building automation and security. Using 6LoWPAN, designers can take advantage of link encryption offered within IEEE 802.15.4 but can also apply transport layer encryption such as DTLS.

Data link and physical protocols

If you examine the many communication protocols available within the IoT, you notice that one in particular, IEEE 802.15.4, plays a significant role as the foundation for other protocols—providing the Physical (PHY) and Medium Access Control (MAC) layers for protocols such as ZigBee, 6LoWPAN, WirelessHART, and even thread.

IEEE 802.15.4

802.15.4 is designed to operate using either point-to-point or star topologies and is ideal for use in low-power or low-speed environments. 802.15.4 devices operate in the 915 MHz and 2.4 GHz frequency ranges, support data rates up to 250 kb/s and communication ranges of roughly 10 meters. The PHY layer is responsible for managing RF network access, while the MAC layer is responsible for managing transmission and receipt of frames onto the data link.

ZWave

Another protocol that operates at this layer of the stack is ZWave. ZWave supports the transmission of three frame types on a network – unicast, multicast, and broadcast. Unicast communications (that is, direct) are acknowledged by the receiver; however, neither multicast nor broadcast transmissions are acknowledged. ZWave networks consist of controllers and slaves. There are variants of each of these, of course. For example, there can be both primary and secondary controllers. Primary controllers have responsibilities such as the ability to add/remove nodes form the network. ZWave operates at 908.42 MHz (North America)/868.42 MHz (Europe) frequency with data rates of 100 kb/s over a range of about 30 meters.

Bluetooth/Bluetooth Smart (also known as Bluetooth Low Energy or BLE) is an evolution of Bluetooth designed for enhanced battery life. Bluetooth Smart achieves its power saving capability by defaulting to sleep mode and only waking when needed. Both operate in the 2.4 GHz frequency range. Bluetooth Smart implements a high-rate frequency-hopping spread spectrum and supports AES encryption.

Reference: http://www.medicalelectronicsdesign.com/article/bluetooth-low-energy-vs-classic-bluetooth-choose-best-wireless-technology-your-application

Power Line Communications

In the energy industry, WirelessHART and Power Line Communications (PLC) technologies such as Insteon are additional technologies that operate at the link and physical layers of the communication stack. PLC-enabled devices (not to be confused with Programmable Logic Controller) can support both home and industrial uses and are interesting in that their communications are modulated directly over existing power lines. This communications method enables power-connected devices to be controlled and monitored without secondary communication conduits.

Reference: http://www.eetimes.com/document.asp?doc_id=1279014

Cellular communications

The move towards 5G communications will have a significant impact on IoT system designs. When 5G rolls out with higher throughput and the ability to support many more connections, we will begin to see increased movement for direct connectivity of IoT devices to the cloud. This will allow for new centralized controller functions to be created that support multitudes of geographically dispersed sensors/actuators with limited infrastructure in place. More robust cellular capabilities will further enable the cloud to be the aggregation point for sensor data feeds, web service interactions, and interfaces to numerous enterprise applications.

IoT data collection, storage, and analytics

So far, we have talked extensively about the endpoints and the protocols that comprise the IoT. Although there is great promise in device-to-device communication and coordination, there are even more opportunities to streamline business processes, enhance customer experiences, and increase capabilities when the power of connected devices is paired with the ability to analyze data. The cloud offers a ready-made infrastructure to support this pairing.

Many public CSPs have deployed IoT services that are well integrated with their other cloud offerings. AWS, for example, has created the AWS IoT service. This service allows IoT devices to be configured and connect to the AWS IoT gateway using MQTT or REST communications. Data can also be ingested into AWS through platforms such as Kinesis or Kinesis Firehose. Kinesis Firehose, for example, can be used to collect and process large streams of data and forward on to other AWS infrastructure components for storage and analysis.

Once data has been collected within a CSP, logic rules can be set up to forward that data where most appropriate. Data can be sent for analysis, storage, or to be combined with other data from other devices and systems. Reasons for the analysis of IoT data run the gamut from wanting to understand trends in shopping patterns (for example, beacons) to predicting whether a machine will break down (predictive maintenance).

Other CSPs have also entered the IoT marketplace. Microsoft's Azure offering now has a specific IoT service in addition to IBM and Google. Even Software as a Service (SaaS) providers have begun offering analytics services. Salesforce.com has designed a tailored IoT analytics solution. Salesforce makes use of the Apache stack to connect devices to the cloud and analyze their large data streams. Salesforce's IoT Cloud relies upon Apache's Cassandra database, the Spark data-processing engine, Storm for data analysis, and Kafka for messaging.

Reference: http://fortune.com/2015/09/15/salesforce-com-iot-cloud/

While today's IoT innovations continue to push the envelope identifying and establishing new relationships between objects, systems, and people, our imaginations continuously dream up new capabilities to solve problems at unprecedented scale. When we apply our imaginative prowess, the promises of the IoT becomes boundless. Today, we are barely scratching the surface.

In this chapter, we saw how the world is developing and advancing towards a better future with the help of the IoT. We also looked at various uses of the IoT in today's world and then had a brief look at its concepts.

In the next chapter, we will learn about the various threats and the measures that we can take to avoid/overcome them.