SWRA846 July   2025 CC2642R-Q1

 

  1.   1
  2.   Abstract
  3. 1Analysis of Bluetooth Pairing Technology Principles
    1. 1.1 LE Legacy Pairing and LE Secure Connections Pairing
    2. 1.2 Analysis of Association Mode Security Characteristics
    3. 1.3 Privacy Protection and Address Management
  4. 2Common Issues in Pairing Encryption
    1. 2.1 Integrity Check Fault—MIC Verification Failure (MIC failure)
    2. 2.2 Abnormal Key Negotiation—DHKey Verification Failure (DHKey check fail)
    3. 2.3 Key Management Defect—PIN/Key Loss (PIN or Key missing)
      1. 2.3.1 Key Missing During Pairing Phase
      2. 2.3.2 LTK Missing During Encryption Phase
  5. 3A Solution for Encryption Resource Conflicts
    1. 3.1 Environment Selection and Configuration
    2. 3.2 Implementing AES-256 Encryption and Decryption Using TinyAES Library
    3. 3.3 System-Level Optimization Exploration
      1. 3.3.1 Memory Allocation Inspection
      2. 3.3.2 Padding Processing and Thread Safety
  6. 4Conclusion
  7. 5References

1.3 Privacy Protection and Address Management

Bluetooth devices are identified by their Bluetooth Device Address (BDA). However, to prevent tracking, BLE devices can enable a privacy feature that substitutes the fixed identity address by periodically generating new addresses, thereby effectively hiding the identity address of the device. Specifically, the address types of Bluetooth devices mainly include the following:

  • Public Address: Uses the permanent identity address of the device, which remains fixed and unchanged.
  • Random Static Address: The device generates a random address at each power-up, and this address does not change during the operation of the device.
  • Resolvable Private Address (RPA): The device periodically generates a random address, which needs to be resolved into its true identity address through the device's Identity Resolving Key (IRK), enhancing privacy.
  • Non-resolvable Private Address: The device periodically generates a completely random address that cannot be resolved to the device's true identity address, used in certain scenarios that do not require identity authentication.

For the detailed process of private address generation and resolution, please refer to the Bluetooth Core Specification and thehttps://dev.ti.com/tirex/explore/content/simplelink_cc13xx_cc26xx_sdk_8_30_01_01/docs/ble5stack/ble_user_guide/html/ble-stack-5.x/gapbondmngr-cc13xx_cc26xx.html#gap-bond-manager-and-le-secure-connections TI BLE5-Stack User's Guide (GAP Bond Manager and LE Secure Connections sections) to obtain deeper information.