The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 27, 2005
Filed:
May. 08, 2001
Bjorn Markus Jakobsson, Hoboken, NJ (US);
Susanne Gudrun Wetzel, New Providence, NJ (US);
Bjorn Markus Jakobsson, Hoboken, NJ (US);
Susanne Gudrun Wetzel, New Providence, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
Master and slave Bluetooth-enabled devices communicate with other by sending messages using a carrier frequency that is constantly hopping from one frequency to another. In the prior art, each frequency in the sequence of frequencies, known as a hopping sequence, is determined as a known function of the master's Bluetooth address (BD_ADDR) and a universal time parameter. A computer-strong eavesdropper who is listening to one or more frequency bands over a period of time and within range of a user's piconet could determine the BD_ADDR of the user's device by comparing a detected hopping sequence with the hopping sequence associated with each possible BD_ADDR. Once the BD_ADDR of a user's device is determined, the user's location can thereafter be tracked as he moves from location to location using that device. To prevent this, the hopping sequence is determined as a known function of the master's BD_ADDR, a universal time parameter and a seed, which is a random or pseudo-random number communicated between the master to the slave and which is changed each time a new session begins on one of the user's devices operating on the piconet. The eavesdropper is then impeded from associating a detected pattern of channel usage with a particular master's BD_ADDR and its user.