User manual

A.1.7.1 Setting up the BPA 600
Figure 7 - ComProbe BPA 600 low energy only datasource
settings
1. Run the ComProbe Protocol Analysis Software
and select Bluetooth Classic/low energy
(BPA 600). This will bring up the BPA 600
datasource window. This is where the
parameters are set for sniffing, including the
devices to be sniffed and how the link is to be
decrypted.
2. Select Devices Under Test tab on the
Datasource window.
3. Click/select LE Only.
4. To decrypt encrypted data transmissions
between the Bluetooth low energy devices the
ComProbe analyzer needs to know the LTK
because this is the shared secret used to
encrypt the session. There are two ways to
provide this information and which to select
will depend on the pairing method: Just Works
or Passkey Entry.
Figure 8 - BPA 600 datasource
Encryption Key Entry
a. Passkey Entry is easiest if you have the code that was
displayed or entered during device pairing. The code is what
is used to generate the LTK. Under LE Encryption enter
the code in the Enter New PIN/OOB data text box.
b. Just Works is more of a challenge because you must know
the LTK that is created at the time of pairing and
identification of an encrypted link.
l If your device was previously used in an encrypted
capture session, the device information including LTK
can be found in the Device Database tab.
l In a design and development environment the LTK is
often known beforehand.
l Capture of Host Controller Interface (HCI) events using ComProbe HSU can reveal the LTK,
which is contained in the HCI_Link_Key_Request_Reply command. HCI capture is through
direct connection to the device host controller. The information obtained in a direct connection
can later be used in a wireless encrypted capture session that requires prior knowledge of
encryption keys.
5.
To start capture click on the Start Sniffing button on the BPA 600 datasource toolbar.
Appendicies TELEDYNE LECROY
Frontline BPA low energy Hardware & Software User Manual 216