The Controller relies on the contents of the resolving list to interact with other private devices. How is it supposed to work? The key is that peripheral's identity. Private Address When a device wants to remain private, it uses private addresses. The reconnect address is exchanged between the two devices at each connection. The addresses it uses are generated with an Identity Resolving Key. This changes periodically based on a timer or other method. It will over-complicate and potentially cause issues where multiple devices are paired e.
There are four types of pairing models. Build the Stack Library and Application projects and flash the device. It does not allow you to connect to a public address without first having scanned for it. It is suggested to review these terms before continuing. Two Random Address Types are provided Static Address A 48-bit randomly generated address. As mentioned earlier, the Resolvable Private Address has a 24-bit prand and 24-bit Hash. The address alone does not do it! Prior to Bluetooth Core Specification v4.
I may mis-understand this, but the name is available in the advertising data, which I believe is available to any device scanning regardless of whitelisting, so I think it should be left as it is. Update: I did some more testing to figure this out. Obviously the peripheral will use the non-resolvable address in the direct advert. In summary, Bluetooth Low Energy devices are difficult to track when using a Resolvable Private Address. The privacy feature inhibits tracking from untrusted peer devices. In essence, 49 bits are necessary to identify an address, not 48. Adding these capabilities enables smaller form factors, better power optimization, and the ability to operate on a small power cell for months or even years.
The following is an example of initiating Passcode Entry pairing where the passcode is displayed. Does the central scan for that particular address and does the peripheral use a directed advertising using that address? But then I don't know how to resolve these manually. Build the Stack Library and Application projects and flash the device. Definition of Privacy Feature Terms Term Definition Resolvable address A resolvable address is one that can potentially be resolved. Once configured, the Link Layer uses it to filter peer devices. A BluetoothDevice will always be returned for a valid hardware address, even if this adapter has never seen that device. This 48-bit 6-byte number uniquely identifies a device among peers.
Each parining mode is described in detail in. It is used during connection mode and connection procedures. On the other hand, a non resolvable private address, has only a probability of 1. Since reconnect addresses only change between connections, device filtering can be used to minimize processing of excessive requests. Address resolution at the Link Layer enables faster connections and reduces power consumption.
With the release of Bluetooth v4. These are addresses that can be periodically changed so that the device can not be tracked. I will add: From core spec Vol 6 Part B section 1. These addresses are then able to be passed to the controller white list for further action, as shown in Figure 63. These examples only consider the pairing aspect. The Random Device Address is classified in two types, Static Random Address and Private Random Address.
The White List, which stores the address type along with the address, is configured by the Host and maintained at the Link Layer. See for more information on how to change predefined project symbols. For more technical information, download the white paper. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Is there something I may be overlooking? Any help or guidance would be appreciated - thanks! Once a device receives the Resolvable Private Address, it extracts the Hash and prand from it. In this pairing method, one device displays a 6-digit passcode, and the other device enters the passcode. Bonding can be added to each type of pairing in the same manner and is shown in the next section.
The address is resolved if they match. White List filtering in the Link Layer can lower power consumption by limiting requests and data passed to the higher layers for processing and interaction. Bluetooth Device Address Bluetooth devices use a 48-bit device address. This provides a way of filtering devices if you only want to communicate with certain devices at a time. This changes with each connection. Frequent changes in Bluetooth 4.