Motorola VC5090 ユーザーズマニュアル

ページ / 258
5 - 2
VC5090 Vehicle Computer Product Reference Guide
Security
The current Bluetooth specification defines security at the link level. Application-level security is not specified. This 
allows application developers to define security mechanisms tailored to their specific need. Link-level security is 
really between devices not users, while application-level security can be implemented on a per-user basis. The 
Bluetooth specification defines security algorithms and procedures needed to authenticate devices, and if needed, 
encrypt the data flowing on the link between the devices. Device authentication is a mandatory feature of Bluetooth 
while link encryption is optional.
Pairing of Bluetooth devices is accomplished by creating an initialization key that is used to authenticate the 
devices and create a link key for them. Entering a common PIN number in the devices being paired generates the 
initialization key. The PIN number is never sent over the air. By default, the Bluetooth stack responds with no key 
when a key is requested (it is up to user to respond to the key request event). Authentication of Bluetooth devices 
is based-upon a challenge-response transaction. Bluetooth allows for a PIN number or passkey that is used to 
create other 128-bit keys used for security and encryption. The encryption key is derived from the link key used to 
authenticate the pairing devices. Also worthy of note is the limited range and fast frequency hopping of the 
Bluetooth radios that makes long-distance eavesdropping difficult.
It is recommended:
Perform pairing in a secure environment
Keep PIN codes private and don't store the PIN codes in the vehicle computer
Implement application-level security.
Turning the Bluetooth Radio Mode On and Off
Turn off the Bluetooth radio to save power or if entering an area with radio restrictions (e.g., an airplane). When the 
radio is off, the vehicle computer can not be seen or connected to by other Bluetooth devices. Turn on the 
Bluetooth radio to exchange information with other Bluetooth devices (within range). Communicate only with 
Bluetooth radios in close proximity.
Disabling Bluetooth
To disable Bluetooth, tap 
 > 
Disable Bluetooth
. The Bluetooth icon changes to indicate that Bluetooth is 
disabled. An exclamation point appears with the icon 
.
Figure 5-1    Disable Bluetooth
Enabling Bluetooth
To enable Bluetooth, tap 
 > 
Enable Bluetooth
. The 
Bluetooth
 icon changes to indicate that Bluetooth is enabled.
NOTE
To achieve the best battery life in vehicle computers with multiple radios, turn off the radios that are not 
being used.