Lightweight Encryption Algorithm For IoT Sensor Nodes — Complete Documentation & Simulation

Overview & System Context

Lightweight Encryption Algorithm For Iot Sensor Nodes: Comprehensive Web-Sourced Technical Investigation Exhaustive Research Dossier · Pure Web-Scraped Content: ~6788 Words · Real Software Screenshots: 3 1. Executive Overview & Technical Background Wireless sensor networks (WSNs) refer to networks of spatially dispersed and dedicated sensors that monitor and record the physical conditions of the environment and forward the collected data to a central location. WSNs can measure environmental conditions such as temperature, sound, pollution levels, humidity and wind. These are similar to wireless ad hoc networks in the sense that they rely on wireless connectivity and spontaneous formation of networks so that sensor data can be transported wirelessly. WSNs monitor physical conditions, such as temperature, sound, and pressure. Modern networks are bi-directional, both collecting data and enabling control of sensor activity. The development of these networks was motivated by military applications such as battlefield surveillance. Such networks are used in industrial and consumer applications, such as industrial process monitoring and control and machine health monitoring and agriculture. A WSN is built of "nodes" – from a few to hundreds or thousands, where each node is connected to other sensors. Each such node typically has several parts: a radio transceiver with an internal antenna or connection to an external antenna, a microcontroller, an electronic circuit for interfacing with the sensors and an energy source, usually a battery or an embedded form of energy harvesting. A sensor node might vary in size from a shoebox to (theoretically) a grain of dust, although microscopic dimensions have yet to be realized. Sensor node cost is similarly variable, ranging from a few to hundreds of dollars, depending on node sophistication.

Size and cost constraints constrain resources such as energy, memory, computational speed and communications bandwidth. The topology of a WSN can vary from a simple star network to an advanced multi-hop wireless mesh network. Propagation can employ routing or flooding. In computer science and telecommunications, wireless sensor networks are an active research area supporting many workshops and conferences, including the International Workshop on Embedded Networked Sensors (EmNetS), International Conference on Information Processing in Sensor Networks (IPSN), SenSys, MobiCom and European Conference on Wireless Sensor Networks (EWSN). As of 2010, wireless sensor networks had deployed approximately 120 million remote units worldwide.

Wireless sensor networks also are used for the collection of data for monitoring of environmental information. This can be as simple as monitoring the temperature in a fridge or the level of water in overflow tanks in nuclear power plants. The statistical information can then be used to show how systems have been working. The advantage of WSNs over conventional loggers is the "live" data feed that is possible.

WSN can be used to monitor the condition of civil infrastructure and related geo-physical processes close to real time, and over long periods through data logging, using appropriately interfaced sensors. Power consumption constraints for nodes using batteries or energy harvesting. Examples of suppliers are ReVibe Energy and Perpetuum Ability to cope with node failures (resilience) Some mobility of nodes (for highly mobile nodes see MWSNs) Heterogeneity of nodes Homogeneity of nodes Scalability to large scale of deployment Ability to withstand harsh environmental conditions Ease of use Cross-layer optimization Cross-layer is becoming an important studying area for wireless communications. In addition, the traditional layered approach presents three main problems: Figure 1: Figure 1 from Comparative Performance Analysis of Lightweight ...

Traditional layered approach cannot share different information among different layers, which leads to each layer not having complete information. The traditional layered approach cannot guarantee the optimization of the entire network. The traditional layered approach does not have the ability to adapt to the environmental change. Because of the interference between the different users, access conflicts, fading, and the change of environment in the wireless sensor networks, traditional layered approach for wired networks is not applicable to wireless networks. So the cross-layer can be used to make the optimal modulation to improve the transmission performance, such as data rate, energy efficiency, quality of service (QoS), etc.

Sensor nodes can be imagined as small computers which are extremely basic in terms of their interfaces and their components. They usually consist of a processing unit with limited computational power and limited memory, sensors or MEMS (including specific conditioning circuitry), a communication device (usually radio transceivers or alternatively optical), and a power source usually in the form of a battery. Other possible inclusions are energy harvesting modules, secondary ASICs, and possibly secondary communication interface (e.g. RS-232 or USB). The base stations are one or more components of the WSN with much more computational, energy and communication resources. They act as a gateway between sensor nodes and the end user as they typically forward data from the WSN on to a server. Other special components in routing based networks are routers, designed to compute, calculate and distribute the routing tables.

One major challenge in a WSN is to produce low cost and tiny sensor nodes. There are an increasing number of small companies producing WSN hardware and the commercial situation can be compared to home computing in the 1970s. Many of the nodes are still in the research and development stage, particularly their software. Also inherent to sensor network adoption is the use of very low power methods for radio communication and data acquisition. In many applications, a WSN communicates with a local area network or wide area network through a gateway. The Gateway acts as a bridge between the WSN and the other network. This enables data to be stored and processed by devices with more resources, for example, in a remotely located server. A wireless wide area network used primarily for low-power devices is known as a Low-Power Wide-Area Network (LPWAN).

Increased lifespan Robustness and fault tolerance Self-configuration Lifetime maximization: Energy/Power Consumption of the sensing device should be minimized and sensor nodes should be energy efficient since their limited energy resource determines their lifetime. To conserve power, wireless sensor nodes normally power off both the radio transmitter and the radio receiver when not in use.

Sensor nodes are prone to failure, For better collection of data, To provide nodes with backup in case of failure of the central node. There is also no centralised body to allocate the resources and they have to be self organized. As for the distributed filtering over distributed sensor network. the general setup is to observe the underlying process through a group of sensors organized according to a given network topology, which renders the individual observer estimates the system state based not only on its own measurement but also on its neighbors'.

Figure 2: Performance Evaluation of Lightweight Cryptographic Algorithms for End ... The data gathered from wireless sensor networks is usually saved in the form of numerical data in a central base station. Additionally, the Open Geospatial Consortium (OGC) is specifying standards for interoperability interfaces and metadata encodings that enable real time integration of heterogeneous sensor webs into the Internet, allowing any individual to monitor or control wireless sensor networks through a web browser.

Bluetooth is a short-range Wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limited to 2.5 milliwatts, giving it a very short range of up to 10 metres (33 ft). It employs UHF radio waves in the ISM bands, from 2.402 GHz to 2.48 GHz. It serves as an alternative to wired connections, and is mainly used to exchange files between nearby portable devices, to connect cell phones and music players with wireless headphones, wireless speakers, HIFI systems, or car audio, and for wireless transmission between TVs and soundbars. Bluetooth is managed by the Bluetooth Special Interest Group (Bluetooth SIG), which has more than 35,000 member companies in the areas of telecommunication, computing, networking, and consumer electronics. The Institute of Electrical and Electronics Engineers (IEEE) standardized Bluetooth as IEEE 802.15.1 but no longer maintains the standard. The Bluetooth SIG oversees the development of the specification, manages the qualification program, and protects the trademarks. A manufacturer must meet Bluetooth SIG standards to market it as a Bluetooth device. A network of patents applies to the technology, which is licensed to individual qualifying devices. As of 2021, 4.7 billion Bluetooth integrated circuit chips are shipped annually. Bluetooth was first demonstrated in space in 2024, an early test envisioned to enhance IoT capabilities.

2. System Architecture & Core Working Principles Bluetooth was only intended as a placeholder until marketing could come up with something really cool. Later, when it came time to select a serious name, Bluetooth was to be replaced with either RadioWire or PAN (Personal Area Networking). PAN was the front runner, but an exhaustive search discovered it already had tens of thousands of hits throughout the internet.

A full trademark search on RadioWire couldn't be completed in time for launch, making Bluetooth the only choice. The name caught on fast and before it could be changed, it spread throughout the industry, becoming synonymous with short-range wireless technology. The development of the "short-link" radio technology, later named Bluetooth, was initiated in 1989 by Nils Rydbeck, CTO at Ericsson Mobile in Lund, Sweden. The purpose was to develop wireless headsets, according to two inventions by Johan Ullman, SE 8902098-6, issued 12 June 1989 and SE 9202239, issued 24 July 1992 . Nils Rydbeck tasked Tord Wingren with specifying and Dutchman Jaap Haartsen and Sven Mattisson with developing. Both were working for Ericsson in Lund.

Principal design and development began in 1994 and by 1997 the team had a workable solution. From 1997 Örjan Johansson became the project leader and propelled the technology and standardization. In 1997, Adalio Sanchez, then head of IBM ThinkPad product R&D, approached Nils Rydbeck about collaborating on integrating a mobile phone into a ThinkPad notebook, but concluded that mobile phone technology power consumption at the time was too high to allow viable integration into a notebook while still achieving adequate battery life. Instead, IBM and Ericsson Mobile agreed to integrate Ericsson's short-link technology into both a ThinkPad notebook and an Ericsson phone to accomplish the goal. Since neither IBM ThinkPad notebooks nor Ericsson phones were the market share leaders in their respective markets at that time, Adalio Sanchez and Nils Rydbeck agreed to make the short-link technology an open industry standard to permit each player maximum market access. Ericsson contributed the short-link radio technology, and IBM contributed patents around the logical layer. Adalio Sanchez of IBM then recruited Stephen Nachtsheim of Intel to join, and then Intel also recruited Toshiba and Nokia. In May 1998, the Bluetooth SIG was launched with IBM and Ericsson as the founding signatories and with a total of five member companies: Ericsson, Intel, Nokia, Toshiba, and IBM. The first Bluetooth device was revealed in 1999. It was a hands-free mobile headset that earned the "Best of show Technology Award" at COMDEX. The first Bluetooth mobile phone was the unreleased prototype Ericsson T36, though it was the revised Ericsson model T39 that actually made it to store shelves in June 2001. However, Ericsson released the R520m in Quarter 1 of 2001, making the R520m the first ever commercially available Bluetooth phone. In parallel, IBM introduced the IBM ThinkPad A30 notebook laptop in October 2001, as the first notebook with integrated Bluetooth. Bluetooth's early incorporation into consumer electronics continued at Vosi Technologies in Costa Mesa, California, initially overseen by founding members Bejan Amini and Tom Davidson. Vosi Technologies had been created by real estate developer Ivano Stegmenga, with United States Patent 5,797,088, for communication between a cellular phone and a vehicle's audio system. Due to ongoing negotiations (beginning in the late 1990s) for an intended licensing agreement with Motorola, Vosi could not publicly disclose the intention, integration, and initial development of other enabled devices which were to be the first "Smart Home" internet connected devices. Vosi needed a means for a system to communicate, without a wired connection, information between a vehicle's audio system and other devices in a network. Bluetooth was chosen because Wi-Fi was not yet readily available or supported in the public market.

Vosi had also begun to develop the Vosi Cello integrated vehicular system and some other internet connected devices, one of which was intended to be a table-top device named the Vosi Symphony, networked with Bluetooth. While in ongoing licensing negotiations with Motorola, Vosi introduced and disclosed its intent to integrate Bluetooth in its devices. In the early 2000s, a legal battle ensued between Vosi and Motorola, which indefinitely suspended release of Vosi's devices. Later, Motorola implemented Bluetooth in its own devices, which initiated significant propagation of Bluetooth in the public market, due to Motorola's larger market share vs Ericsson at the time. In 2012, Jaap Haartsen was nominated by the European Patent Office for the European Inventor Award.

Historically, the Bluetooth range was defined by the radio class, with a lower class (and higher output power) having larger range. The actual range of a given link depends on several qualities of both communicating devices and the air and obstacles in between. The primary attributes affecting range are the data rate, protocol (Bluetooth Classic or Bluetooth Low Energy), transmission power, and receiver sensitivity, and the relative orientations and gains of both antennas. The effective range varies depending on propagation conditions, material coverage, production sample variations, antenna configurations and battery conditions. Most Bluetooth applications are for indoor conditions, where attenuation of walls and signal fading due to signal reflections make the range far lower than specified line-of-sight ranges of the Bluetooth products. Most Bluetooth applications are battery-powered Class 2 devices, with little difference in range whether the other end of the link is a Class 1 or Class 2 device as the lower-powered device tends to set the range limit. In some cases the effective range of the data link can be extended when a Class 2 device is connecting to a Class 1 transceiver with both higher sensitivity and transmission power than a typical Class 2 device. In general, however, Class 1 devices have sensitivities similar to those of Class 2 devices. Connecting two Class 1 devices with both high sensitivity and high power can allow ranges far in excess of the typical 100 m, depending on the throughput required by the application. Some such devices allow open field ranges of up to 1 km and beyond between two similar devices without exceeding legal emission limits.

Figure 3: Unforgeable Digital Signature Integrated into Lightweight Encryption ... To use Bluetooth wireless technology, a device must be able to interpret certain Bluetooth profiles. For example, The Headset Profile (HSP) connects headphones and earbuds to a cell phone or laptop. The Health Device Profile (HDP) can connect a cell phone to a digital thermometer or heart rate detector. The Video Distribution Profile (VDP) sends a video stream from a video camera to a TV screen or a recording device. Profiles are definitions of possible applications and specify general behaviors that Bluetooth-enabled devices use to communicate with other Bluetooth devices. These profiles include settings to parameterize and to control the communication from the start. Adherence to profiles saves the time for transmitting the parameters anew before the bi-directional link becomes effective. There are a wide range of Bluetooth profiles that describe many different types of applications or use cases for devices.

Wireless control and communication between a mobile phone and a handsfree headset. This was one of the earliest applications to become popular. Wireless control of audio and communication functions between a mobile phone and a Bluetooth compatible car stereo system (and sometimes between the SIM card and the car phone). Wireless communication between a smartphone and a smart lock for unlocking doors. Wireless control of and communication with iOS and Android device phones, tablets and portable wireless speakers. Wireless Bluetooth headset and intercom. Idiomatically, a headset is sometimes called "a Bluetooth". Wireless streaming of audio to headphones with or without communication capabilities.

Wireless streaming of data collected by Bluetooth-enabled fitness devices to phone or PC. Wireless networking between PCs in a confined space and where little bandwidth is required. Wireless communication with PC input and output devices, the most common being the mouse, keyboard and printer. Transfer of files, contact details, calendar appointments, and reminders between devices with OBEX and sharing directories via FTP. Triggering the camera shutter of a smartphone using a Bluetooth controlled selfie stick. Replacement of previous wired RS-232 serial communications in test equipment, GPS receivers, medical equipment, bar code scanners, and traffic control devices. For controls where infrared was often used. For low bandwidth applications where higher USB bandwidth is not required and cable-free connection desired. Sending small advertisements from Bluetooth-enabled advertising hoardings to other, discoverable, Bluetooth devices. Wireless bridge between two Industrial Ethernet (e.g., PROFINET) networks. Game consoles have been using Bluetooth as a wireless communications protocol for peripherals since the seventh generation, including Nintendo's Wii and Sony's PlayStation 3 which use Bluetooth for their respective controllers. Dial-up internet access on personal computers or PDAs using a data-capable mobile phone as a wireless modem. Short-range transmission of health sensor data from medical devices to mobile phone, set-top box or dedicated telehealth devices. Allowing a DECT phone to ring and answer calls on behalf of a nearby mobile phone. Real-time location systems (RTLS) are used to track and identify the location of objects in real time using "Nodes" or "tags" attached to, or embedded in, the objects tracked, and "Readers" that receive and process the wireless signals from these tags to determine their locations. Personal security application on mobile phones for prevention of theft or loss of items. The protected item has a Bluetooth marker (e.g., a tag) that is in constant communication with the phone. If the connection is broken (the marker is out of range of the phone) then an alarm is raised. This can also be used as a man overboard alarm. Calgary, Alberta, Canada's Roads Traffic division uses data collected from travelers' Bluetooth devices to predict travel times and road congestion for motorists. Wireless transmission of audio (a more reliable alternative to personal FM transmitters) Live video streaming to the visual cortical implant device by Nabeel Fattah in Newcastle university 2017.

Connection of motion controllers to a PC when using VR headsets Wireless connection between TVs and soundbars. Bluetooth exists in numerous products such as telephones, speakers, tablets, media players, robotics systems, laptops, and game console equipment as well as some high definition headsets, modems, hearing aids and even watches. Bluetooth is useful when transferring information between two or more devices that are near each other in low-bandwidth situations.

Bluetooth is commonly used to transfer sound data with telephones (i.e., with a Bluetooth headset) or byte data with hand-held computers (transferring files). Bluetooth protocols simplify the discovery and setup of services between devices. Bluetooth devices can advertise all of the services they provide. This makes using services easier, because more of the security, network address and permission configuration can be automated than with many other network types.

A personal computer that does not have embedded Bluetooth can use a Bluetooth adapter that enables the PC to communicate with Bluetooth devices. While some desktop computers and most recent laptops come with a built-in Bluetooth radio, others require an external adapter, typically in the form of a small USB "dongle". Unlike its predecessor, IrDA, which requires a separate adapter for each device, Bluetooth lets multiple devices communicate with a computer over a single adapter.

For Microsoft platforms, Windows XP Service Pack 2 and SP3 releases work natively with Bluetooth v1.1, v2.0 and v2.0+EDR. Previous versions required users to install their Bluetooth adapter's own drivers, which were not directly supported by Microsoft. Microsoft's own Bluetooth dongles (packaged with their Bluetooth computer devices) have no external drivers and thus require at least Windows XP Service Pack 2. Windows Vista RTM/SP1 with the Feature Pack for Wireless or Windows Vista SP2 work with Bluetooth v2.1+EDR. Windows 7 works with Bluetooth v2.1+EDR and Extended Inquiry Response (EIR). The Windows XP and Windows Vista/Windows 7 Bluetooth stacks support the following Bluetooth profiles natively: PAN, SPP, DUN, HID, HCRP. The Windows XP stack can be replaced by a third party stack that supports more profiles or newer Bluetooth versions. The Windows Vista/Windows 7 Bluetooth stack supports vendor-supplied additional profiles without requiring that the Microsoft stack be replaced. Windows 8 and later support Bluetooth Low Energy (BLE). It is generally recommended to install the latest vendor driver and its associated stack to be able to use the Bluetooth device at its fullest extent. Apple products have worked with Bluetooth since Mac OS X v10.2, which was released in 2002. Linux has two popular Bluetooth stacks, BlueZ and Fluoride. The BlueZ stack is included with most Linux kernels and was originally developed by Qualcomm. Fluoride, earlier known as Bluedroid, is included in Android OS and was originally developed by Broadcom. There is also Affix stack, developed by Nokia. It was once popular, but has not been updated since 2005.

FreeBSD has included Bluetooth since its v5.0 release, implemented through netgraph. NetBSD has included Bluetooth since its v4.0 release. Its Bluetooth stack was ported to OpenBSD as well, however OpenBSD later removed it as unmaintained. DragonFly BSD has had NetBSD's Bluetooth implementation since 1.11 (2008). A netgraph-based implementation from FreeBSD has also been available in the tree, possibly disabled until 2014-11-15, and may require more work.

3. Software Implementation, Frameworks & Protocols The specifications were formalized by the Bluetooth Special Interest Group (SIG) and formally announced on 20 May 1998. In 2014 it had a membership of over 30,000 companies worldwide. It was established by Ericsson, IBM, Intel, Nokia and Toshiba, and later joined by many other companies. All versions of the Bluetooth standards are backward compatible with all earlier versions. The Bluetooth Core Specification Working Group (CSWG) produces mainly four kinds of specifications: The Bluetooth Core Specification – typically released every few years Core Specification Addendum (CSA) Core Specification Supplements (CSS) – can be released more frequently than Addenda Errata – published privately to Bluetooth SIG members Faster connection and discovery Adaptive frequency-hopping spread spectrum (AFH), which improves resistance to radio frequency interference by avoiding the use of crowded frequencies in the hopping sequence Higher transmission speeds in practice than in v1.1, up to 721 kbit/s Extended Synchronous Connections (eSCO), which improve voice quality of audio links by allowing retransmissions of corrupted packets, and may optionally increase audio latency to provide better concurrent data transfer Host Controller Interface (HCI) operation with three-wire UART Ratified as IEEE Standard 802.15.1–2005 Introduced flow control and retransmission modes for L2CAP L2CAP Enhanced modes Enhanced Retransmission Mode (ERTM) implements reliable L2CAP channel, while Streaming Mode (SM) implements unreliable channel with no retransmission or flow control. Introduced in Core Specification Addendum 1. Alternative MAC/PHY Enables the use of alternative MAC and PHYs for transporting Bluetooth profile data. The Bluetooth radio is still used for device discovery, initial connection and profile configuration. However, when large quantities of data must be sent, the high-speed alternative MAC PHY 802.11 (typically associated with Wi-Fi) transports the data. This means that Bluetooth uses proven low power connection models when the system is idle, and the faster radio when it must send large quantities of data. AMP links require enhanced L2CAP modes. Unicast Connectionless Data Permits sending service data without establishing an explicit L2CAP channel. It is intended for use by applications that require low latency between user action and reconnection/transmission of data. This is only appropriate for small amounts of data. Enhanced Power Control Updates the power control feature to remove the open loop power control, and also to clarify ambiguities in power control introduced by the new modulation schemes added for EDR. Enhanced power control removes the ambiguities by specifying the behavior that is expected. The feature also adds closed loop power control, meaning RSSI filtering can start as the response is received. Additionally, a "go straight to maximum power" request has been introduced. This is expected to deal with the headset link loss issue typically observed when a user puts their phone into a pocket on the opposite side to the headset.

The Bluetooth SIG completed the Bluetooth Core Specification version 4.0 (called Bluetooth Smart) and has been adopted as of 30 June 2010. It includes Classic Bluetooth, Bluetooth high speed and Bluetooth Low Energy (BLE) protocols. Bluetooth high speed is based on Wi-Fi, and Classic Bluetooth consists of legacy Bluetooth protocols. Bluetooth Low Energy, previously known as Wibree, is a subset of Bluetooth v4.0 with an entirely new protocol stack for rapid build-up of simple links. As an alternative to the Bluetooth standard protocols that were introduced in Bluetooth v1.0 to v3.0, it is aimed at very low power applications powered by a coin cell. Chip designs allow for two types of implementation, dual-mode, single-mode and enhanced past versions. The provisional names Wibree and Bluetooth ULP (Ultra Low Power) were abandoned and the BLE name was used for a while. In late 2011, new logos "Bluetooth Smart Ready" for hosts and "Bluetooth Smart" for sensors were introduced as the general-public face of BLE. Compared to Classic Bluetooth, Bluetooth Low Energy is intended to provide considerably reduced power consumption and cost while maintaining a similar communication range. In terms of lengthening the battery life of Bluetooth devices, BLE represents a significant progression.

In a single-mode implementation, only the low energy protocol stack is implemented. Dialog Semiconductor, STMicroelectronics, AMICCOM, CSR, Nordic Semiconductor and Texas Instruments have released single mode Bluetooth Low Energy solutions. In a dual-mode implementation, Bluetooth Smart functionality is integrated into an existing Classic Bluetooth controller. As of March 2011, the following semiconductor companies have announced the availability of chips meeting the standard: Qualcomm Atheros, CSR, Broadcom and Texas Instruments. The compliant architecture shares all of Classic Bluetooth's existing radio and functionality resulting in a negligible cost increase compared to Classic Bluetooth.

Cost-reduced single-mode chips, which enable highly integrated and compact devices, feature a lightweight Link Layer providing ultra-low power idle mode operation, simple device discovery, and reliable point-to-multipoint data transfer with advanced power-save and secure encrypted connections at the lowest possible cost. General improvements in version 4.0 include the changes necessary to facilitate BLE modes, as well the Generic Attribute Profile (GATT) and Security Manager (SM) services with AES Encryption. Core Specification Addendum 2 was unveiled in December 2011; it contains improvements to the audio Host Controller Interface and to the High Speed (802.11) Protocol Adaptation Layer. Core Specification Addendum 3 revision 2 has an adoption date of 24 July 2012. Core Specification Addendum 4 has an adoption date of 12 February 2013.

Mobile wireless service coexistence signaling Train nudging and generalized interlaced scanning Low Duty Cycle Directed Advertising L2CAP connection-oriented and dedicated channels with credit-based flow control Dual Mode and Topology LE Link Layer Topology 802.11n PAL Audio architecture updates for Wide Band Speech Fast data advertising interval Limited discovery time Some features were already available in a Core Specification Addendum (CSA) before the release of v4.1.

Bluetooth Low Energy Secure Connection with Data Packet Length Extension to improve the cryptographic protocol Link Layer Privacy with Extended Scanner Filter Policies to improve data security Internet Protocol Support Profile (IPSP) version 6 ready for Bluetooth smart devices to support the Internet of things and home automation Older Bluetooth hardware may receive 4.2 features such as Data Packet Length Extension and improved privacy via firmware updates.

Slot Availability Mask (SAM) 2 Mbit/s PHY for LE LE Long Range High Duty Cycle Non-Connectable Advertising LE Advertising Extensions LE Channel Selection Algorithm #2 Features added in CSA5 – integrated in v5.0: Higher Output Power The following features were removed in this version of the specification: 4. Practical Deployment, Analysis & Case Studies Angle of arrival (AoA) and Angle of Departure (AoD) which are used for locating and tracking of devices Advertising Channel Index GATT caching Minor Enhancements batch 1: HCI support for debug keys in LE Secure Connections Sleep clock accuracy update mechanism ADI field in scan response data Interaction between QoS and Flow Specification Block Host channel classification for secondary advertising Allow the SID to appear in scan response reports Specify the behavior when rules are violated Periodic Advertising Sync Transfer Features added in Core Specification Addendum (CSA) 6 – integrated in v5.1: Models Mesh-based model hierarchy The following features were removed in this version of the specification: Enhanced Attribute Protocol (EATT), an improved version of the Attribute Protocol (ATT) LE Power Control LE Isochronous Channels LE Audio that is built on top of the new 5.2 features. BT LE Audio was announced in January 2020 at CES by the Bluetooth SIG. Compared to regular Bluetooth Audio, Bluetooth Low Energy Audio makes lower battery consumption possible and creates a standardized way of transmitting audio over BT LE. Bluetooth LE Audio also allows one-to-many and many-to-one transmission, allowing multiple receivers from one source or one receiver for multiple sources, known as Auracast. It uses a new LC3 codec. BLE Audio will also add support for hearing aids. On 12 July 2022, the Bluetooth SIG announced the completion of Bluetooth LE Audio. The standard has a lower minimum latency claim of 20–30 ms vs Bluetooth Classic audio of 100–200 ms. At IFA in August 2023 Samsung announced support for Auracast through a software update for their Galaxy Buds2 Pro and two of their TVs. In October users started getting updates for the earbuds.

Connection Subrating Periodic Advertisement Interval Channel Classification Enhancement Encryption key size control enhancements The following features were removed in this version of the specification: Periodic Advertising with Responses (PAwR) Encrypted Advertising Data LE GATT Security Levels Characteristic Advertising Coding Selection Bluetooth Channel Sounding Decision-based advertising filtering Monitoring advertisers ISOAL enhancement LL extended feature set Frame space update HCI USB LE Isochronous support LE Direct Test Mode enhancements Shorter connection intervals Channel Sounding amplitude-based attack resilience Channel Sounding Inline Phase Correction Term Transfer Channel Sounding PHY-specific RTT Accuracy Running Out of Bits Removed: Bluetooth is defined as a layer protocol architecture consisting of core protocols, cable replacement protocols, telephony control protocols, and adopted protocols. Mandatory protocols for all Bluetooth stacks are LMP, L2CAP and SDP. In addition, devices that communicate with Bluetooth almost universally can use these protocols: HCI and RFCOMM.

Transmission and reception of data. Name request Request of the link addresses. Establishment of the connection. Authentication. Negotiation of link mode and connection establishment. 5. Performance Evaluation & Extended Technical Observations Enhanced Retransmission Mode (ERTM) This mode is an improved version of the original retransmission mode. This mode provides a reliable L2CAP channel. Streaming Mode (SM) This is a very simple mode, with no retransmission or flow control.

This mode provides an unreliable L2CAP channel. Reliability in any of these modes is optionally and/or additionally guaranteed by the lower layer Bluetooth BDR/EDR air interface by configuring the number of retransmissions and flush timeout (time after which the radio flushes packets). In-order sequencing is guaranteed by the lower layer. Only L2CAP channels configured in ERTM or SM may be operated over AMP logical links.

Point-to-Point Protocol (PPP) Internet standard protocol for transporting IP datagrams over a point-to-point link. TCP/IP/UDP Foundation Protocols for TCP/IP protocol suite Object Exchange Protocol (OBEX) Session-layer protocol for the exchange of objects, providing a model for object and operation representation Wireless Application Environment/Wireless Application Protocol (WAE/WAP) WAE specifies an application framework for wireless devices and WAP is an open standard to provide mobile users access to telephony and information services.

Device name Device class List of services Technical information (for example: device features, manufacturer, Bluetooth specification used, clock offset) Any device may perform an inquiry to find other devices to connect to, and any device can be configured to respond to such inquiries. However, if the device trying to connect knows the address of the device, it always responds to direct connection requests and transmits the information shown in the list above if requested. Use of a device's services may require pairing or acceptance by its owner, but the connection itself can be initiated by any device and held until it goes out of range. Some devices can be connected to only one device at a time, and connecting to them prevents them from connecting to other devices and appearing in inquiries until they disconnect from the other device. Every device has a unique 48-bit address. However, these addresses are generally not shown in inquiries. Instead, friendly Bluetooth names are used, which can be set by the user. This name appears when another user scans for devices and in lists of paired devices. Most cellular phones have the Bluetooth name set to the manufacturer and model of the phone by default. Most cellular phones and laptops show only the Bluetooth names and special programs are required to get additional information about remote devices.

This can be confusing as, for example, there could be several cellular phones in range named T610 (see Bluejacking). Legacy pairing: This is the only method available in Bluetooth v2.0 and before. Each device must enter a PIN code; pairing is only successful if both devices enter the same PIN code. Any 16-byte UTF-8 string may be used as a PIN code; however, not all devices may be capable of entering all possible PIN codes. Limited input devices: The obvious example of this class of device is a Bluetooth Hands-free headset, which generally have few inputs. These devices usually have a fixed PIN, for example "0000" or "1234", that are hard-coded into the device. Numeric input devices: Mobile phones are classic examples of these devices. They allow a user to enter a numeric value up to 16 digits in length. Alpha-numeric input devices: PCs and smartphones are examples of these devices. They allow a user to enter full UTF-8 text as a PIN code. If pairing with a less capable device the user must be aware of the input limitations on the other device; there is no mechanism available for a capable device to determine how it should limit the available input a user may use. Secure Simple Pairing (SSP): This is required by Bluetooth v2.1, although a Bluetooth v2.1 device may only use legacy pairing to interoperate with a v2.0 or earlier device. Secure Simple Pairing uses a form of public-key cryptography, and some types can help protect against man in the middle, or MITM attacks. SSP has the following authentication mechanisms: Just works: As the name implies, this method just works, with no user interaction. However, a device may prompt the user to confirm the pairing process. This method is typically used by headsets with minimal IO capabilities, and is more secure than the fixed PIN mechanism this limited set of devices uses for legacy pairing. This method provides no man-in-the-middle (MITM) protection. Numeric comparison: If both devices have a display, and at least one can accept a binary yes/no user input, they may use Numeric Comparison. This method displays a 6-digit numeric code on each device. The user should compare the numbers to ensure they are identical. If the comparison succeeds, the user(s) should confirm pairing on the device(s) that can accept an input. This method provides MITM protection, assuming the user confirms on both devices and actually performs the comparison properly. Passkey Entry: This method may be used between a device with a display and a device with numeric keypad entry (such as a keyboard), or two devices with numeric keypad entry. In the first case, the display presents a 6-digit numeric code to the user, who then enters the code on the keypad. In the second case, the user of each device enters the same 6-digit number. Both of these cases provide MITM protection. Out of band (OOB): This method uses an external means of communication, such as near-field communication (NFC) to exchange some information used in the pairing process. Pairing is completed using the Bluetooth radio, but requires information from the OOB mechanism. This provides only the level of MITM protection that is present in the OOB mechanism. SSP is considered simple for the following reasons: In most cases, it does not require a user to generate a passkey. For use cases not requiring MITM protection, user interaction can be eliminated. For numeric comparison, MITM protection can be achieved with a simple equality comparison by the user.

Using OOB with NFC enables pairing when devices simply get close, rather than requiring a lengthy discovery process. Turning off encryption is required for several normal operations, so it is problematic to detect if encryption is disabled for a valid reason or a security attack. Bluetooth v2.1 addresses this in the following ways: Encryption is required for all non-SDP (Service Discovery Protocol) connections A new Encryption Pause and Resume feature is used for all normal operations that require that encryption be disabled. This enables easy identification of normal operation from security attacks. The encryption key must be refreshed before it expires. Link keys may be stored on the device file system, not on the Bluetooth chip itself. Many Bluetooth chip manufacturers let link keys be stored on the device—however, if the device is removable, this means that the link key moves with the device.

Bluetooth implements confidentiality, authentication and key derivation with custom algorithms based on the SAFER+ block cipher. Bluetooth key generation is generally based on a Bluetooth PIN, which must be entered into both devices. This procedure might be modified if one of the devices has a fixed PIN (e.g., for headsets or similar devices with a restricted user interface). During pairing, an initialization key or master key is generated, using the E22 algorithm. The E0 stream cipher is used for encrypting packets, granting confidentiality, and is based on a shared cryptographic secret, namely a previously generated link key or master key. Those keys, used for subsequent encryption of data sent via the air interface, rely on the Bluetooth PIN, which has been entered into one or both devices. An overview of Bluetooth vulnerabilities exploits was published in 2007 by Andreas Becker. In September 2008, the National Institute of Standards and Technology (NIST) published a Guide to Bluetooth Security as a reference for organizations. It describes Bluetooth security capabilities and how to secure Bluetooth technologies effectively. While Bluetooth has its benefits, it is susceptible to denial-of-service attacks, eavesdropping, man-in-the-middle attacks, message modification, and resource misappropriation. Users and organizations must evaluate their acceptable level of risk and incorporate security into the lifecycle of Bluetooth devices. To help mitigate risks, included in the NIST document are security checklists with guidelines and recommendations for creating and maintaining secure Bluetooth piconets, headsets, and smart card readers. Bluetooth v2.1 – finalized in 2007 with consumer devices first appearing in 2009 – makes significant changes to Bluetooth's security, including pairing. See the pairing mechanisms section for more about these changes.

Bluejacking is the sending of either a picture or a message from one user to an unsuspecting user through Bluetooth wireless technology. Common applications include short messages, e.g., "You've just been bluejacked!" Bluejacking does not involve the removal or alteration of any data from the device. Some form of DoS is also possible, even in modern devices, by sending unsolicited pairing requests in rapid succession; this becomes disruptive because most systems display a full screen notification for every connection request, interrupting every other activity, especially on less powerful devices.

In 2004 the first purported virus using Bluetooth to spread itself among mobile phones appeared on the Symbian OS. The virus was first described by Kaspersky Lab and requires users to confirm the installation of unknown software before it can propagate. The virus was written as a proof-of-concept by a group of virus writers known as "29A" and sent to anti-virus groups. Thus, it should be regarded as a potential (but not real) security threat to Bluetooth technology or Symbian OS since the virus has never spread outside of this system. In August 2004, a world-record-setting experiment showed that the range of Class 2 Bluetooth radios could be extended to 1.78 km (1.11 mi) with directional antennas and signal amplifiers. This poses a potential security threat because it enables attackers to access vulnerable Bluetooth devices from a distance beyond expectation. The attacker must also be able to receive information from the victim to set up a connection. No attack can be made against a Bluetooth device unless the attacker knows its Bluetooth address and which channels to transmit on, although these can be deduced within a few minutes if the device is in use.

Harvested Online Documentation & Reference Sources • https://en.wikipedia.org/wiki/Wireless%20sensor%20network • https://en.wikipedia.org/wiki/Bluetooth