Encryption type for Bluetooth security

[Eleazar]

hey friends,

just for the information I wanted to know the technology applied behind the Bluetooth application enabling high level security in an open network....
What type of encryption is used in Bluetooth security ?

thanks

[Big Fish]

Bluetooth security is a concern that many people have. It is a common misconception that all Bluetooth devices can connect to any other device and browse the information on it. This cannot be done without the user setting the device to do so. Bluetooth security has various levels of authentication including pin code entry and up to 128-bit encryption.

Bluetooth Pass Key -

• This is a unique, case-sensitive password that is required in order to access and communicate with another Bluetooth device.
• The Pass Key is continually incorporated into the 128-bit Encryption; also it reinforces pairing by only allowing devices to pair if the password matches.

[Big Fish]

Some more features -

Bluetooth Pairing - This convenient Bluetooth security feature remembers the Pass Key used to allow communication with another Bluetooth device. For two devices to be paired, the same Pass Key must be entered on both devices. Pairing lets Bluetooth devices remain permanently linked to each other, until you un-pair them. Even if a “paired” Bluetooth device is turned off, or just out of range, it will be visible to the Bluetooth devices it has been paired with when it is powered on again or comes within wireless-signal range.

Bluetooth Encryption - Bluetooth features 128-bit security encryption to make sure that no other devices can receive transmissions that you send.

Stealth Mode - Some Bluetooth devices have the ability to turn off the ‘Discoverable’ setting. When a Bluetooth device is Discoverable, it broadcasts its existence to other Bluetooth devices and announces that it is available for Bluetooth communications. When you turn off discoverability, your device will not appear to other Bluetooth devices searching the airwaves for partners. This can come in handy if you're in a public area with curious Bluetooth-bearing strangers.

[Steve123]

The Bluetooth specification 1.0 describes the link encryption algorithm as a stream cipher using 4 LFSR.
LFSR - Linear Feedback Shift Registers.

The sum of the width of the LFSRs is 128, and the spec says "the effective key length is selectable between 8 and 128 bits". This arrangement allows Bluetooth to be used in countries with regulations limiting encryption strength, and "facilitate a future upgrade path for the security without the need for a costly redesign of the algorithms and encryption hardware" according to the Bluetooth specification.

Key generation and authentication seems to be using the 8-round SAFER+ encryption algorithm.

The information available suggests that Bluetooth security will be adequate for most purposes; but users with higher security requirements will need to employ stronger algorithms to ensure the security of their data.