Motorola MC75A, Руководство пользователя

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6 - 2 MC75A Enterprise Digital Assistant User Guide
The Bluetooth radio in this MC75A operates as a Class 2 device power class. The maximum output power is
2.5mW and the expected range is 32.8 feet (10 meters). A definition of ranges based on power class is difficult to
obtain due to power and device differences, and whether one measures open space or closed office space.
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
occurs 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.
Recommendations are:
•
Perform pairing in a secure environment
•
Keep PIN codes private and don't store the PIN codes in the mobile computer
•
Implement application-level security.
The Microsoft stack supports Smart-pairing. For detailed information, refer to the Microsoft MSDN.
The StoneStreet One Bluetooth stack supports Secure Simple Pairing. Secure Simple Pairing improves the pairing
experience for Bluetooth devices and increasing the use and strength of security. Both the host and the remote
device must support Secure Simple Pairing. If one device does not, standard pairing will be used, as described
above.
NOTE
It is not recommended to perform Bluetooth wireless technology inquiry when high rate 802.11b operation is
required.