139BTTracer Protocol Analyzer User’s ManualCATC Version 1.011.4 BT NeighborhoodThe BT Neighborhood status box displays information about knownBluetooth™ devices. This command is accessible through the View menuin the menu bar. Three types of data are displayed: Device Address, Classof Device (COD), and the Bluetooth™ Clock Frequency for eachdiscovered device. The expected Bluetooth™ clock frequency is 3200 Hz+/- 250 PPM.11.5 EncryptionBluetooth encryption is a multi-staged process that provides devices withsecure, encrypted communications. The process begins with a deviceprompting the user for a Personal Identification Number (PIN). When theright PIN is entered, the Slave begins an encryption setup dialogue with theMaster. At the beginning of this dialogue, the Slave and the Master agreeon a Link Key. A Link Key is a 128-bit value that the two devices use forauthentication. When the Slave and Master agree on a Link Key, the Slavethen negotiates for the transfer of the Encryption Key from the Masterdevice. The Encryption Key is used to encrypt and decrypt messages. Oncethe Encryption Key is transferred, both devices use it to encrypt allsubsequent communications.In order for BTTracer to decode encrypted traffic, it needs the Link Key foreach Master-Slave connection for which encryption will be used. If youknow the Link Key, you can enter the Key into the Encryption Optionsdialog box. If you do not know it, you give BTTracer the PIN for a device
