728x90

The Bluetooth Special Interest Group (SIG) Board of Directors has approved the release of two versions of the Bluetooth® Core Specification annually, starting in 2025. The first release under this new cadence is targeted for Spring 2025.

 

Over the past decade, the SIG has typically released a new core specification every 18 months, timed with the completion of a major new Bluetooth feature. While this approach has been effective in enabling the delivery of transformative updates, it has also meant that other Bluetooth features, enhancements, and fixes had to wait until the completion of a major feature before being released. To address this, the SIG will now follow a more frequent release cycle, publishing two updates to the Bluetooth® Core Specification each year. This will allow the introduction of completed features on a more consistent and frequent basis, ensuring faster innovation and continuous improvement.

 

"Moving to a bi-annual release cycle for the Bluetooth Core Specification represents a pivotal step forward for the entire Bluetooth technology ecosystem," said Alain Michaud, Chair of the Board of Directors for the Bluetooth SIG. "This new cadence will ensure that incremental improvements and features can reach developers and manufacturers faster, fueling innovation and helping them meet the evolving needs of the market with greater agility. By adopting this approach, we’re not just accelerating the development cycle—we’re also reinforcing the Bluetooth SIG’s commitment to continually strengthen the foundation for the future of wireless connectivity."

 

As a reminder, Bluetooth SIG members are strongly encouraged to avoid communicating the version of the Bluetooth® Core Specification against which a product was qualified (e.g., Bluetooth Core 6.0) to describe the Bluetooth functionality supported in that product. Doing so can create misunderstandings about the product’s capabilities. For example, a device qualified to Bluetooth Core 6.0 is not required to contain any of the new features added in Bluetooth Core 6.0 or even in Bluetooth Core 5.0.

 

Instead, members should focus on clearly and accurately describing the specific Bluetooth features their product supports, emphasizing those most important to their target customers, in product packaging, documentation, and promotional materials. Guidance for effectively communicating support for specific Bluetooth features and applications in member products can be found here: Communicating Supported Bluetooth® Functionality.

 

Details about the upcoming Spring 2025 release will be shared as soon as they are available.

 

Sincerely, 

 

The Bluetooth SIG 

========================================================================================

 

 Bluetooth SIG에서 1년에 2차례 version을 release하기로 결정했다.

기존에는 큰 변화가 있을 때마다 core version을 올렸는데 이제는 Android처럼 주기적으로 version을 올리고 알아서 new feature를 선택하도록 권장하고 있다.

때문에 제품을 홍보할 때도 Core version에 의미를 두지 말라고 한다.

사실 이 문제는 Bluetooth를 담당하던 사람들도 많이 헷갈리던 부분인데 기능들이 optional로 되어 있어 core version이 높다고 해서 그 모든 기능을 지원하는 것이 아닌데 오해가 많이 생기기 때문이다.

 

이제는 core version별로 어떤 기능이 추가되었나보다는 어떠한 기능들이 있느냐에 초점을 맞추고 세부적으로 어느 버전부터 추가 되었나 정도만 알면 될 것 같다.

728x90
728x90

 

TK : Temporary Key
STK를 만들기 위해 생성(128bit Numeric)

STK : Short Term Key
s1 함수의 경우 입력 매개변수에는 다음이 포함
* TK (Temporary Key)
* Srand (응답장치가 생성한 난수)
* Mrand (시작장치가 생성한 난수)

페어링된 장치는 STK와 암호화된 연결 사용

LTK : Long Term Key
링크키 개념, 다음 연결에 사용, MITM 공격 방지

IRK : Identify Resolving Key
private random address를 public address로 분석하는데 사용되는 키
pairing할 때 LTK, IRK를 저장

 

728x90
728x90

Security algorithms

secure only connection : secure connection만 연결 받아줌

secure connection : LMP feature ext host/controller supported 가 있음(SSP, encryption 지원 여부도 있음)

 

Level 4 : secure connection

Level 3 : secure connection을 지원하지 않을 경우 :SSP는 지원

Level 2 : SSP 지원하지 않음, encryption은 지원

Level 1 : SSP를 지원하지 않고 core 2.0 이하일 경우

Level 0 : security 사용하지 않음(profile에서 none으로 설정하는 경우에만 사용할 수 있음)

 

 

 

Chip level

  • SHA - Secure Hash Algorithms
  • HMAC - Hash-based message authentication code
  • RSA - Rivest–Shamir–Adleman ( A public-key cryptosystem )
  • ECC - Elliptic-curve cryptography
  • ECDH - Elliptic Curve Diffie-Hellman Exchange
  • ECDSA - Elliptic Curve Digital Signature Authentication
  • SE - Secure enclave
728x90
728x90

Nomenclature

 

Active Peripheral Broadcast(APB) The logical transport that is used to transport L2CAP user traffic and some kinds of LMP traffic to all active devices in the piconet over the BR/EDR Controller. See Section 3.5.4.4
Ad Hoc Network A network typically created in a spontaneous manner. An ad hoc network requires no formal infrastructure and is limited in temporal and spatial extent.
Advertiser A Bluetooth Low Energy device that broadcasts advertising packets during advertising events on advertising channels
Advertising event A series of between one and three advertising packets on different advertising physical channels sent by an advertiser.
Advertising Packet A packet containing an advertising PDU. See [Vol 6] Part B, Section 2.3.1
Angle of Arrival (AoA) Angle of Arrival is the relative direction at which a propagating RF wave that was transmitted by a single antenna is incident on an antenna array.
Angle of Departure (AoD) Angle of Departure is the relative direction from which a propagating RF wave that was transmitted using an antenna array is incident on another antenna.
BD_ADDR The Bluetooth Device Address, BD_ADDR, is used to identify a Bluetooth device.
Bluetooth Bluetooth is a wireless communication link, operating in the unlicensed ISM band at 2.4 GHz using a frequency hopping transceiver. It allows real-time AV and data communications between Bluetooth Hosts. The link protocol is based on time slots.
Bluetooth Baseband The part of the Bluetooth system that specifies or implements the medium access and physical layer procedures to support the exchange of real-time voice, data information streams, and ad hoc networking between Bluetooth Devices.
Bluetooth Clock A 28 bit clock internal to a BR/EDR Controller sub-system that ticks every 312.5 µs. The value of this clock defines the slot numbering and timing in the various physical channels.
Bluetooth Controller A generic term referring to a Controller.
Bluetooth Device A device that is capable of short-range wireless communications using the Bluetooth system.
Bluetooth Device Address A 48 bit address used to identify each Bluetooth device.
BR/EDR Bluetooth basic rate (BR) and enhanced data rate (EDR).
BR/EDR Controller A term referring to the Bluetooth Radio, Baseband, Link Manager, and HCI layers.
BR/EDR Piconet Physical Channel A Channel that is divided into time slots in which each slot is related to an RF hop frequency. Consecutive hops normally correspond to different RF hop frequencies and occur at a standard hop rate of 1600 hops per second. These consecutive hops follow a pseudo-random hopping sequence, hopping through a 79 RF channel set, or optionally fewer channels when Adaptive Frequency Hopping (AFH) is in use.
BR/EDR/LE Bluetooth basic rate (BR), enhanced data rate (EDR) and low energy (LE).
C-plane Control plane
Channel Either a physical channel or an L2CAP channel, depending on the context.
Channel Sounding A Bluetooth Low Energy feature that measures and distributes information that can be used to approximate distances between devices.
Channel Sounding event A group of Channel Sounding subevents that are anchored from a common LE connection event.
Channel Sounding procedure A group of Channel Sounding events that are sequenced serially for the purpose of gathering information useful for estimating the distance between two devices.
Channel Sounding step In Channel Sounding, an individual exchange between two devices.
Channel Sounding subevent A group of Channel Sounding steps that are associated with a specific coherent timing.
Connect (to service) The establishment of a connection to a service. If not already done, this also includes establishment of a physical link, logical transport, logical link and L2CAP channel.
Connectable device A BR/EDR device in range that periodically listens on its page scan physical channel and will respond to a page on that channel. An LE device that is advertising using a connectable advertising event.
Connected devices Two BR/EDR devices and with a physical link between them.
Connecting A phase in the communication between devices when a connection between the devices is being established. (Connecting phase follows after the link establishment phase is completed.)
Connection A connection between two peer applications or higher layer protocols mapped onto an L2CAP channel.
Connection establishment A procedure for creating a connection mapped onto a channel.
Connection event A series of one or more pairs of interleaving data packets sent between a Central and a Peripheral on the same physical channel.
Connectionless Peripheral Broadcast (CPB) A feature that enables a Central to broadcast information to an unlimited number of Peripherals.
Connectionless Peripheral Broadcast Receiver A Bluetooth device that receives broadcast information from a Connectionless Peripheral Broadcast Transmitter. The device is a Peripheral of the piconet.
Connectionless Peripheral Broadcast Transmitter A Bluetooth device that sends Connectionless Peripheral Broadcast messages for reception by one or more Connectionless Peripheral Broadcast receivers. The device is the Central of the piconet.
Controller A collective term referring to all of the layers below HCI.
Coverage area The area where two Bluetooth devices can exchange messages with acceptable quality and performance.
Creation of a secure connection A procedure of establishing a connection, including authentication and encryption.
Creation of a trusted relationship A procedure where the remote device is marked as a trusted device. This includes storing a common link key for future authentication, or pairing, when a link key is not available.
Device discovery A procedure for retrieving the Bluetooth Device Address, clock, and Class of Device from discoverable devices.
Discoverable device A BR/EDR device in range that periodically listens on an inquiry scan physical channel and will respond to an inquiry on that channel. An LE device in range that is advertising with a connectable or scannable advertising event with a discoverable flag set in the advertising data. This device is in the discoverable mode.
Discoverable Mode A Bluetooth device that is performing inquiry scans in BR/EDR or advertising with a discoverable or connectable advertising event with a discoverable flag set in LE.
Discovery procedure A Bluetooth device that is carrying out the inquiry procedure in BR/EDR or scanning for advertisers using a discoverable or connectable advertising event with a discoverable flag set in LE.
HCI The Host Controller interface (HCI) provides a command interface to the baseband Controller and link manager and access to hardware status and control registers. This interface provides a uniform method of accessing the Bluetooth baseband capabilities.
Host A logical entity defined as all of the layers below the non-core profiles and above the Host Controller interface (HCI); i.e., the layers specified in Volume 3. A Bluetooth Host attached to a Bluetooth Controller may communicate with other Bluetooth Hosts attached to their Controllers as well.
Initiator From the perspective of an advertising bearer, a Bluetooth Low Energy device that listens on advertising physical channels for connectable advertising events to form connections. From the perspective of Channel Sounding, the device that transmits first within a Channel Sounding step. 
Inquiring device A BR/EDR device that is carrying out the inquiry procedure. This device is performing the discovery procedure.
Inquiry A procedure where a Bluetooth device transmits inquiry messages and listens for responses in order to discover the other Bluetooth devices that are within the coverage area.
Inquiry scan A procedure where a Bluetooth device listens for inquiry messages received on its inquiry scan physical channel.
Interoperability The ability of two or more devices to exchange information and to use the information that has been exchanged.
Isochronous data Information in a stream where each information entity in the stream is bound by a time relationship to previous and successive entities.
Known device A Bluetooth device for which at least the BD_ADDR is stored.
L2CAP Logical Link Control and Adaptation Protocol
L2CAP Channel A logical connection on L2CAP level between two devices serving a single application or higher layer protocol.
L2CAP Channel establishment A procedure for establishing a logical connection on L2CAP level.
LE Bluetooth Low Energy
Link Shorthand for a logical link.
Link establishment A procedure for establishing the default ACL link and hierarchy of links and channels between devices.
Link key A secret key that is known by two devices and is used to authenticate the link.
LMP authentication An LMP level procedure for verifying the identity of a remote device.
LMP pairing A procedure that authenticates two devices and creates a common link key that can be used as a basis for a trusted relationship or a (single) secure connection.
Logical link The lowest architectural level used to offer independent data transport services to clients of the Bluetooth system.
Logical transport Shared acknowledgment protocol and link identifiers between different logical links.
Name discovery A procedure for retrieving the user-friendly name (the Bluetooth Device Name) of a connectable device.
Packet Format of aggregated bits that are transmitted on a physical channel.
Page The initial phase of the connection procedure where a device transmits a train of page messages until a response is received from the target device or a time-out occurs.
Page scan A procedure where a device listens for page messages received on its page scan physical channel.
Paging device A Bluetooth device that is carrying out the page procedure.
Paired device A Bluetooth device for which a link key has been created (either before connection establishment was requested or during connecting phase).
Passkey A 6-digit number used to authenticate connections when Secure Simple Pairing is used.
Periodic advertising synchronization information The control information describing a periodic advertisement that a Bluetooth Low Energy device uses to synchronize to the advertisement it describes.
Physical Channel Characterized by synchronized occupancy of a sequence of RF carriers by one or more devices. A number of physical channel types exist with characteristics defined for their different purposes.
Physical link A Baseband or Link Layer level connection between two devices.
Physical Transport PHY packet transmission and/or reception on an RF channel using one or more modulation schemes.
Piconet A collection of devices (up to eight devices in BR/EDR, exactly two devices in LE) occupying a shared physical channel where one of the devices is the Piconet Central and the remaining devices are connected to it.
Piconet Central The BR/EDR device in a piconet whose Bluetooth Clock and Bluetooth Device Address are used to define the piconet physical channel characteristics. The LE device in a piconet which initiates the creation of the piconet, chooses the Access Address that identifies the piconet, and transmits first in each connection event. 
Piconet Peripheral Any BR/EDR device in a piconet that is not the Piconet Central, but is connected to the Piconet Central. The LE device in a piconet which is not the Central but communicates with it.
PIN A user-friendly number that can be used to authenticate connections to a device before pairing has taken place.
Profile Broadcast Data (PBD) A logical link that carries data from a Connectionless Peripheral Broadcast Transmitter to one or more Connectionless Peripheral Broadcast Receivers.
Pseudo-Noise Bit Sequence A series of bits that are generated randomly.
Reflector In Channel Sounding, the device that transmits second within a Channel Sounding step in response to a transmission from an initiator.
Resolving List A list of records used to generate and resolve Resolvable Private Addresses. Each record contains a local Identity Resolving Key, a peer Identity Resolving Key, and a peer Identity Address.
Round-Trip Time The time it takes for a packet to travel from an originating device to a responding device and back again to the originating device.
Scanner A Bluetooth Low Energy device that listens for advertising events on the advertising physical channels.
Scatternet Two or more piconets that have one or more devices in common.
Service discovery Procedures for querying and browsing for services offered by or through another Bluetooth device.
Service Layer Protocol A protocol that uses an L2CAP channel for transporting PDUs.
Silent device A Bluetooth enabled device appears as silent to a remote device if it does not respond to inquiries made by the remote device.
Synchronization Scan Physical Channel A physical channel that enables a Peripheral to receive synchronization train packets from a Central.
Synchronization Train A series of packets transmitted on a set of fixed frequencies that deliver sufficient information for a receiving device to start receiving corresponding Connectionless Peripheral Broadcast packets or to recover the current piconet clock after missing a Coarse Clock Adjust.
Tick (BR/EDR) the time between changes of the value of the Bluetooth Clock: 312.5 µs.
U-plane User plane
Unknown device A Bluetooth device for which no information (Bluetooth Device Address, link key or other) is stored.
728x90

+ Recent posts