BlueGate 1000
Appendix—A, Intro to BT
May 8, 2001
WIDCOMM, Inc, Proprietary and Confidential
A-4
Encryption
The Bluetooth specification allows for encrypted transactions using a key size of up to
128 bits.
Some Bluetooth devices do not support encryption. If a device or service is configured to
use encryption and attempts a connection with a device that does not support encryption
the connection may fail unexpectedly.
Advantages of encryption
: Protects against radio frequency snooping.
Disadvantages of encryption
: The receiving unit must also support encryption.
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Service Level
Each Bluetooth service can be selectively disabled. If all Bluetooth services are disabled
the local computer is unable to accept connections from a remote computer.
The local machine can still initiate outgoing connections to other Bluetooth units, but
incoming connections will not be allowed.
Advantages of service level security
: Strong security.
Disadvantages of service level security
: It is non-selective; it shuts out all incoming
Bluetooth connections for a particular service.
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Link Keys
To avoid entering a passkey over-and-over for a known and trusted remote device, a link
key can be created.
A link key is a number created from:
•
The passkey.
•
The Bluetooth device address of the remote device.
•
An internally random-generated number.
There is no limit to the number link keys that may be created.
Devices that share a link key are “bonded.” Bonded devices are authenticated
automatically, without operator intervention.
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