The National Institute of Standards and Technology Special Publication 800-121 Revision 1, Guide to Bluetooth Security is the first revision to NIST SP 800-121, Guide to Bluetooth Security. Bluetooth is an open standard for short-range radio frequency communication. Bluetooth technology is used primarily to establish wireless personal area networks. It has been integrated into many types of business and consumer devices, including cellular phones, personal digital assistants, laptops, automobiles, printers, and headsets. This publication provides information on the security capabilities of Bluetooth and gives recommendations to organizations employing Bluetooth technologies on securing them effectively. Updates in this revision include the latest vulnerability mitigation information for Secure Simple Pairing, introduced in Bluetooth v2.1 + Enhanced Data Rate (EDR), as well as an introduction to and discussion of Bluetooth v3.0 + High Speed and Bluetooth v4.0 security mechanisms and recommendations.