Patent Publication Number: US-7907900-B2

Title: Method and apparatus that mitigates the effects of bluetooth-based denial of service attacks against mobile devices

Description:
BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     This disclosure relates to the mitigation of risk of Bluetooth-based Denial of Service (DoS) attacks against mobile devices equipped with Bluetooth technology. 
     2. Introduction 
     A mobile communications device equipped with Bluetooth technology may be vulnerable to a Denial of Service (DoS) attack. In a Bluetooth-based DoS attack, an attacking device sends a rapid stream of Bluetooth messages to a victim device. This rapid stream of Bluetooth messages may impair the function of the victim device by depleting its battery power, flooding its display with Bluetooth messages, blocking legitimate Bluetooth messages, etc. As such, the limited resources of the victim device render this attack especially effective. 
     In order to mitigate the effects of a DoS attack, conventional techniques dictate that the victim device block the Bluetooth address of the attacking device. However, this countermeasure is ineffective since the attacking device may change Bluetooth addresses throughout the attack. 
     SUMMARY OF THE DISCLOSURE 
     A method and apparatus that mitigates the effects of a Bluetooth-based Denial of Service (DoS) attack on a Bluetooth-enabled mobile communications device is disclosed. The method may include determining if the mobile communications device is under a DoS attack, wherein if it is determined that the mobile communications device is under a DoS attack, the method may include temporarily disabling Bluetooth services that were enabled using a first Bluetooth address, storing the first Bluetooth address in a memory in the mobile communications device, changing the first Bluetooth address to a second Bluetooth address, and enabling Bluetooth services using the second Bluetooth address. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description of the disclosure briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the disclosure will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG. 1  illustrates an exemplary diagram of a mobile communication system in accordance with a possible embodiment of the disclosure; 
         FIG. 2  illustrates an exemplary diagram of a mobile communication device in accordance with a possible embodiment of the disclosure; and 
         FIG. 3  is an exemplary flowchart illustrating one possible Bluetooth address recasting process in accordance with one possible embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. The features and advantages of the disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present disclosure will become more fully apparent from the following description and appended claims, or may be learned by the practice of the disclosure as set forth herein. 
     Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. 
     The disclosure comprises a variety of embodiments, such as a method and apparatus and other embodiments that relate to the basic concepts of the disclosure. 
     This disclosure concerns the recasting of a mobile communication device&#39;s Bluetooth address in response to a Bluetooth-based Denial of Service (DoS) attack. In a Bluetooth-based DoS attack, the attacking device attacks the victim device by sending a high volume of messages, such as a rapid stream of messages, to the particular Bluetooth address of the victim device. In an embodiment of this disclosure, the mobile communication device may change its Bluetooth address, thereby altering the physical characteristics of the communication channel, so that the victim device will not receive Bluetooth messages from the attacking device. 
       FIG. 1  illustrates an exemplary diagram of a mobile communication system  100  in accordance with a possible embodiment of the disclosure. The mobile communication system  100  may include mobile communication devices  120 ,  140  and attacking device  130  connected through communications network  110 . 
     Communications network  110  may represent any network that may transmit and receive Bluetooth wireless signals. 
     The mobile communication device  120 ,  140  may be any device capable of sending and receiving communication signals and capable of using Bluetooth technology. For example, the mobile communication device  120 ,  140  may be a wireless telephone, cellular telephone, mobile telephone, portable MP3 player, satellite radio receiver, AM/FM radio receiver, satellite television, portable laptop, portable computer, wireless radio, portable digital video recorder, or personal digital assistant PDA), for example. 
     The attacking device  130  may be any device capable of sending and receiving communication signals, including sending Bluetooth messages. For example, the attacking device  130  may be a computer, personal computer, server, wireless telephone, cellular telephone, mobile telephone, satellite radio transmitter, portable laptop, portable computer, wireless radio, or PDA, for example. 
     In accordance with this disclosure, the attacking device  130  may invoke tactics to prevent the mobile communication device  120  from adequately using its own resources including its ability to communicate with other mobile communication devices  140 . Such tactics may include the attacking device  130  sending large quantities of Bluetooth messages to the mobile communication device  120  so that all or a substantial portion of the mobile communication device&#39;s resources are consumed. The mobile communication device  120  invokes the processes of the exemplary embodiments described herein to combat such an attack. 
       FIG. 2  illustrates a block diagram of a mobile communication device  120 . The mobile communications device  120  may include a bus  210 , a processor  220 , a memory  230 , an antenna  240 , a transceiver  250 , a communication interface  260 , user interface  270 , and Bluetooth address recasting module  280 . Bus  210  may permit communication among the components of the mobile communication device  120 . 
     Processor  220  may include at least one conventional processor or microprocessor that interprets and executes instructions. Memory  230  may be a random access memory (RAM) or another type of dynamic storage device that stores information and instructions for execution by processor  220 . Memory  230  may also include a read-only memory (ROM) which may include a conventional ROM device or another type of static storage device that stores static information and instructions for processor  220 . 
     Transceiver  250  may include one or more transmitters and receivers. The transceiver  250  may include sufficient functionality to interface with any network or communications station and may be defined by hardware or software in any manner known to one of skill in the art. The processor  220  is cooperatively operable with the transceiver  250  to support operations within the communications network  110 . The transceiver  250  transmits and receives transmissions via the antenna  240  in a manner known to those of skill in the art. 
     Communication interface  260  may include any mechanism that facilitates communication via the network  110 . For example, communication interface  260  may include a modem. Alternatively, communication interface  260  may include other mechanisms for assisting the transceiver  250  in communicating with other devices and/or systems via wireless connections. 
     User interface  270  may include one or more conventional input/output mechanisms that permit a user to input information and communicate with the mobile communication device  120 , such as a microphone, touchpad, keypad, display, keyboard, mouse, pen, stylus, voice recognition device, buttons, one or more speakers, etc. 
     The mobile communication device  120  may perform such functions in response to processor  220  by executing sequences of instructions contained in a computer-readable medium, such as, for example, memory  230 . Such instructions may be read into memory  230  from another computer-readable medium, such as a storage device or from a separate device via communication interface  260 . 
     The details of the operation of the Bluetooth address recasting module  280  will be found below in the discussion of the exemplary flowchart in  FIG. 3 . 
       FIG. 3  is an exemplary flowchart illustrating one possible Bluetooth address recasting process in accordance with one possible embodiment of the disclosure. The process begins at step  3100  and continues to step  3200  where the Bluetooth address recasting module  280  may determine if the mobile communications device is under a DoS attack. In a Bluetooth-based DoS attack, the attacking device  130  may send a rapid stream of messages to the particular Bluetooth address of the mobile communication device  120 . The recasting of the Bluetooth address of the mobile communication device  120  may be initiated by the user or automatically by the mobile communication device  120  once the number or rate of Bluetooth events, such as connections, has passed a predetermined threshold, for example. 
     If it is determined that the mobile communications device  120  is under a DoS attack, then at step  3300 , the Bluetooth address recasting module  280  may temporarily disable Bluetooth services that were enabled using a first Bluetooth address. At step  3400 , the Bluetooth address recasting module  280  may store the first Bluetooth address in a memory  230  in the mobile communications device  110 . This will enable the first Bluetooth address to be used after the DoS threat is removed, such as when the mobile communication device  120  is operated in a different location or after a particular time period expires, for example. 
     At step  3500 , the Bluetooth address recasting module  280  may change the first Bluetooth address to a second Bluetooth address. In changing its Bluetooth address, the physical characteristics of the Bluetooth communication channel are altered and the mobile communication device  120  will not receive Bluetooth messages from the attacking device  130 . The Bluetooth address may be selected at random or be pre-designated as part of an address stack, for example. At step  3600 , the Bluetooth address recasting module  280  may enable Bluetooth services using the second Bluetooth address. The process then goes to step  3700  and ends. 
     Although the above description may contain specific details, they should not be construed as limiting the claims in any way. Other configurations of the described embodiments of the disclosure are part of the scope of this disclosure. The appended claims and their legal equivalents should only define the disclosure, rather than any specific examples given.