Guide to Bluetooth Security: Recommendations of the National Institute of Standards and Technology (Special Publication 800-121)

Guide to Bluetooth Security: Recommendations of the National Institute of Standards and Technology (Special Publication 800-121) Review

Bluetooth is an open standard for short-range radio frequency (RF) communication. Bluetooth technology is used primarily to establish wireless personal area networks (WPAN), commonly referred to as ad hoc or peer-to-peer (P2P) networks. Bluetooth technology has been integrated into many types of business and consumer devices, including cellular phones, personal digital assistants (PDA), laptops, automobiles, printers, and headsets. This allows users to form ad hoc networks between a wide variety of devices to transfer voice and data. This document provides an overview of Bluetooth technology and discusses related security concerns. There have been several versions of Bluetooth, with the most recent being 2.0 + Enhanced Data Rate (EDR) (November 2004) and 2.1 + EDR (July 2007). While 2.0 + EDR provided faster transmission speeds than previous versions (up to 3 Mbits/second), 2.1 + EDR provides a significant security improvement for link key generation and management in the form of Secure Simple Pairing (SSP). This publication addresses the security of these versions of Bluetooth, as well as the earlier versions 1.1 and 1.2. Bluetooth technology and associated devices are susceptible to general wireless networking threats, such as denial of service attacks, eavesdropping, man-in-the-middle attacks, message modification, and resource misappropriation. They are also threatened by more specific Bluetooth-related attacks that target known vulnerabilities in Bluetooth implementations and specifications. Attacks against improperly secured Bluetooth implementations can provide attackers with unauthorized access to sensitive information and unauthorized usage of Bluetooth devices and other systems or networks to which the devices are connected. To improve the security of Bluetooth implementations, organizations should implement the following recommendations: Organizations should use the strongest Bluetooth security mode available for their Bluetooth devices. The Bluetooth specifications define four security modes, and each version of Bluetooth supports some, but not all, of these modes. The modes vary primarily by how well they protect Bluetooth communications from potential attack. Security Mode 3 is considered the strongest mode because it requires authentication and encryption to be established before the Bluetooth physical link is completely established. Security Modes 2 and 4 also use authentication and encryption, but only after the Bluetooth physical link has already been fully established and logical channels partially established. Security Mode 1 provides no security functionality. The available modes vary based on the Bluetooth specification versions of both devices, so organizations should choose the most secure mode available for each case.