Information Technology Reference
In-Depth Information
These methods are implemented in link layer and in this level, to improve
security, we use different keys. They also implement four safety parameters:
•
Bluetooth Device Address (BD-ADDR) is a unique public address to 48
bit possessed by each device Bluetooth.
•
RAND is a 128-bit random number, generated for each transaction, from
the same device, which builds the channel and the encryption key. It is
extremely unlikely that a value is repeated over time while an
authentication key is valid, making impossible to predict its value.
•
Key Link is a private key 128-bit used for authentication between two or
more units. It can be either a temporary key (a key to initialize or a master
key) or semi-temporary (unit or combination key).
•
Encryption key is a secret key to 8-bit or 128-bit encryption used each
time a session is started.
4.2
Security manager
The security manager is the key component in the Bluetooth architecture
(Figure 3). It fact, it manages all the security procedures at the services level,
and maintains a database of different security requirements of services and
levels of safety device. The security manager handles the following tasks [8-10]:
•
Information storage, related to security, on devices
: the security manager
uses the device database to store addresses, the key link and the level of
confidence of slave devices that have communicated with the master unit
in the past.
Figure 3: The Bluetooth architecture
