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BACKGROUND OF THE INVENTION  
       [0001]     1. Technical Field  
         [0002]     The present invention is related generally to anti-theft devices for computer equipment. Specifically, the present invention is directed to a cable lock system that may be unlocked by a computer.  
         [0003]     2. Description of the Related Art  
         [0004]     As computer equipment has become smaller and increasingly portable, the problem of equipment theft has become a greater concern. A number of security devices exist in the art for preventing the theft of computer equipment. One particular type of device that is frequently used is a cable lock apparatus. U.S. Patent Grant MURRAY et al. (U.S. Pat. No. 5,502,989) 1996-4-2 provides examples of typical cable lock devices as exist in the art.  
         [0005]     One common configuration for a cable lock device, as known in the art, is presented in  FIG. 1 . A device  100  to be protected from theft (in this case, a video display monitor) is outfitted with an aperture  102  that is adapted to allow a flexible cable  104  to be threaded through it. One end of cable  104  is terminated in a padlock  106 ; the other end is terminated in a mushroom-shaped terminal  108 , which is adapted to be inserted into padlock  106 . When terminal  108  is inserted into padlock  106 , a pin, ring, or other retaining mechanism (not shown) engages with terminal  108  to prevent terminal  108  from being removed from padlock  106  unless a key  110  is inserted into padlock  106  and turned, in which case, the retaining mechanism is released. To use the device depicted in  FIG. 1  for theft prevention, cable  104  is threaded through aperture  102  as well as some other aperture (not shown) that is attached to a fixed location (such as a wall or the surface of a counter or desk) before locking terminal  108  into padlock  106 .  
         [0006]     Another cable lock device that is commonly employed in conjunction with notebook computers and other highly portable devices is shown in  FIG. 2 . A device  200  to be protected (in this case, a computer keyboard) is outfitted with a built-in aperture (not visible in  FIG. 2 ). Cable  202  is terminated on one end by a locking plug  204  (shown in greater detail in  FIG. 3 ) that is adapted to be attached to device  200  through device  200 &#39;s built-in aperture and locked/unlocked to/from device  200  through the use of a key inserted and turned within circular keyhole  206 .  
         [0007]      FIGS. 3, 4 , and  5  illustrate the locking mechanism employed by plug  204 . A rotatable elongate member  300  extends outward from plug  204 . To attach plug  204  to device  200 , one inserts member  300  through an elongate aperture  402  in an outer wall  400  of device  200 , as shown in  FIG. 4 . Plug  204  is locked in place by inserting a key  500  into circular keyhole  206  and turning key  500  a quarter turn. This causes member  300  to also rotate a quarter turn to become generally perpendicular to the longitudinal axis of aperture  402 , as shown in  FIG. 5 . When member  300  is perpendicular to the longitudinal axis of aperture  402 , plug  204  may not be removed from wall  400  and is thus locked in place.  
         [0008]     Returning now to  FIG. 2 , the other end of cable  202  is terminated in a loop  208 . As suggested by  FIG. 2 , the preferred method of use of the device is for the plug-end of cable  202  to be threaded through loop  208  to make a larger loop. If cable  202  is also threaded to a aperture permanently affixed to a tabletop, wall, or other stationary surface (not shown), one will be physically prevented from removing device  200  from the immediate vicinity of that stationary surface.  
         [0009]     While the devices shown in  FIGS. 1-5  are, from a purely physical standpoint, highly effective in preventing equipment theft, their effectiveness as a theft-preventative can be limited in practice as the result of a number of factors. In particular, when a cable lock apparatus is used in conjunction with equipment that is intended to be portable (such as a notebook computer), the cable lock apparatus will, in general, be used to provide only temporary protection from theft at a particular location. For example, an employee-user who takes his or her notebook computer home from work may only utilize the cable lock while at work. This means that the user must make regular use of a key to unlock the cable lock before taking the equipment home.  
         [0010]     In practice, this regular reliance on a physical key tends to lead to security compromises. Specifically, the need to use a key on a frequent basis requires that the user not lose or misplace the key, or else the cable lock cannot be unlocked and the equipment may not be removed when necessary. Rather than keeping up with a separate key, then, some users may, for the sake of convenience, leave the key in the keyhole of the cable lock or otherwise attach the key to the cable lock itself. In particular, a corporate user with a company-issued notebook computer may be required to utilize a cable lock at work, as company policy, but may be more motivated by convenience than by preventing theft of company-owned equipment. This practice of leaving the key in the lock, however, essentially defeats the purpose of the cable lock in the first place, and is an unacceptable security risk.  
         [0011]     Thus, what is needed is a cable lock apparatus which prevents security compromises by user practices such as leaving the key in the lock. The present invention provides a solution to this and other problems, and offers other advantages over previous solutions.  
       SUMMARY  
       [0012]     Accordingly, a preferred embodiment of the present invention is directed to a cable lock apparatus that is operated by the computer equipment that the apparatus is intended to protect, rather than by a key. According to this preferred embodiment, the cable lock is equipped with a hot-swappable computer interface, such as a Universal Serial Bus (USB) interface, for connecting to the computer. The user of the computer unlocks the cable lock by providing a password or other form of authentication to the computer. The computer transmits this authentication information, via the USB interface, to circuitry within the cable lock device, which validates the authentication information. If the authentication information validates properly, the cable lock device circuitry activates a motor or solenoid to mechanically release the cable lock.  
         [0013]     The foregoing is a summary and thus contains, by necessity, simplifications, generalizations, and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the present invention, as defined solely by the claims, will become apparent in the non-limiting detailed description set forth below.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The present invention may be better understood, and its numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings, wherein  
         [0015]      FIG. 1  is a diagram of a padlock-equipped cable lock device as known in the art;  
         [0016]      FIG. 2  is a diagram of a plug-equipped cable lock device as known in the art;  
         [0017]      FIG. 3  is a diagram illustrating the plug utilized in the cable lock device of  FIG. 2  in greater detail;  
         [0018]      FIGS. 4 and 5  illustrate steps in the insertion and locking of the cable lock device in  FIG. 2  to a built-in aperture of a device to be protected;  
         [0019]      FIG. 6  is a pictorial diagram providing an external view of a cable lock device in accordance with a preferred embodiment of the present invention;  
         [0020]      FIG. 7  is a deployment diagram illustrating relationships between hardware and software components in a computer-operated cable lock apparatus in accordance with a preferred embodiment of the present invention;  
         [0021]      FIG. 8  is a diagram of a dialog box used to obtain authentication information from a user of the host computer that is being used to unlock a cable lock apparatus in accordance with a preferred embodiment of the present invention;  
         [0022]      FIG. 9  is a flowchart representation of a process of unlocking a cable lock apparatus in accordance with a preferred embodiment of the present invention;  
         [0023]      FIG. 10  is a block diagram illustrating the electronic hardware contained within a cable lock apparatus in accordance with a preferred embodiment of the present invention; and  
         [0024]      FIG. 11  is a block diagram of an exemplary host computer system that may be used in conjunction with a cable lock apparatus constructed in accordance with a preferred embodiment of the present invention to unlock the cable lock apparatus.  
     
    
     DETAILED DESCRIPTION  
       [0025]     The following is intended to provide a detailed description of an example of the invention and should not be taken to be limiting of the invention itself. Rather, any number of variations may fall within the scope of the invention, which is defined in the claims following the description.  
         [0026]      FIG. 6  is a pictorial diagram providing an external view of a cable lock device  600  in accordance with a preferred embodiment of the present invention. Cable lock device  600 , like the cable lock device depicted in  FIG. 2 , utilizes a cable  602  that is attached to a plug  604 . Plug  604  uses a similar mechanism to that depicted in  FIGS. 3-5  to attach plug  604  to a hardware device, such as a mobile computer. Cable  602  is preferably affixed at one end to a stationary surface in a manner similar to the device in  FIG. 2 .  
         [0027]     Cable lock device  600  has an attached USB (Universal Serial Bus) cable  606 , which may be used to connect cable lock device  600  to an available USB port on a host computer system. The USB interface standard is particularly suited for use in an embodiment of the present invention, because USB devices are “hot swappable.” This means that a USB device may be connected to or disconnected from a host computer system without disrupting the operation of the host. In general, computer systems that utilize hot swappable interfaces such as USB are capable of detecting when a device has been connected. In a preferred embodiment of the present invention, the act of connecting USB cable  606  to a USB port on a running computer system is detected by the operating system of the host computer system. The operating system then causes software (such as a device driver) to execute to prompt the user to enter a password to either lock or unlock device  600  (by manipulating plug  604 ). Once cable lock device  600  is either locked or unlocked, as desired, USB cable  606  may be unplugged from the host computer&#39;s USB port.  
         [0028]     In an alternative mode of operation, USB cable  606  may be left plugged into the host computer. In this alternative mode, the software that prompts the user to enter a password is executed in response to either the user&#39;s issuing a command to the host computer to execute the software or the user&#39;s actuating lock/unlock request switch  608 , which is mounted on cable lock device  600 . Cable lock device  600  also includes its own USB port  610 . This allows cable lock device  600  to be continuously plugged into the host computer, but without sacrificing an additional USB port. USB port  610  takes the place of the USB port that is occupied by USB cable  606 .  
         [0029]     One of ordinary skill in the art will also recognize that an embodiment of the present invention may take other forms. For example, the computer-controlled, password-protected unlocking employed by cable lock device  600  may be integrated into a padlock-style cable lock device, such as that depicted in  FIG. 1  (the primary difference being that in a typical padlock, one generally may lock the device simply by physically closing the padlock itself-thus, only the unlocking of the padlock need be computer-controlled). Other appropriate physical forms of the invention will be apparent to those of ordinary skill in the art and may be applied to the teachings of the present invention without departing from the scope and spirit thereof.  
         [0030]      FIG. 7  is a deployment diagram illustrating relationships between hardware and software components in a computer-operated cable lock apparatus in accordance with a preferred embodiment of the present invention. The two main hardware components are a host computer  700  and a USB (Universal Serial Bus) peripheral  702 . In a preferred embodiment of the present invention, USB peripheral  702  comprises electronics that are physically integrated into a cable lock device and that may be connected to a host computer system through a USB interface (e.g., USB connection  704 ).  
         [0031]     One of ordinary skill in the art will recognize that embodiments of the present invention are not limited to the use of a USB interface, but may employ any of a number of computer-to-device interfaces without departing from the scope and spirit of the present invention. For example, the IEEE-1374 standard (commonly referred to in the industry as “FireWire”) is another hot-swappable interface standard that may be used instead of USB. In addition, one of ordinary skill in the art will recognize that it is also possible to construct an embodiment of the present invention using a non-hot-swappable interface. Moreover, other non-electrical interfaces, such as optical or wireless interfaces may be used in an embodiment of the present invention, without departing from the scope and spirit of the present invention. For example, some computer systems employ short-range wireless interfaces, such as the BLUETOOTH industry standard or one of the various IEEE (Institute of Electrical and Electronics Engineers) 802.11 standards for ad hoc wireless networking, for connecting a host computer to peripheral devices.  
         [0032]     A software component  706  resides on host computer  700  and is used to obtain authenticating information from a user. In a preferred embodiment, this authenticating information is a password, although other sources of authenticating information, such as a code stored on a smart card, may be employed as well.  
         [0033]     In this preferred embodiment, software component  706  is invoked in response to a determination that USB peripheral  702  has been connected to host computer  700  (e.g., via USB connection  704 ). For example, software component  706  may be contained within device driver code that is invoked by an operating system residing on host computer  700  in response to USB peripheral  702 &#39;s first being physically connected to host computer  700 . Component  706 , once invoked, may display a message or prompt such as dialog box  800  in  FIG. 8 , which prompts the user to enter a password in text field  802  and click OK button  804  to unlock the cable lock. A similar dialog box may be used to enter a password to lock the cable lock.  
         [0034]     Whatever authenticating information is received by component  706  is transmitted over USB connection  704  to USB peripheral  702 , where a validation circuitry  708  validates the authenticating information received based upon additional information stored in non-volatile memory of USB peripheral  702 . In this preferred embodiment, a received password is compared to a stored password  710 , however, other forms of authentication/validation are well known and available to those skilled in the art and may be employed within an embodiment of the present invention without limitation and without departing from the scope and spirit thereof. The reader is directed to Chapter 10 (pp. 385-424) of MENEZES et al. Handbook of Applied Cryptography. Boca Raton, Fla.: CRC Press, 1997, ISBN 0-8493-8523-7 for a discussion of various authentication schemes known and available to those skilled in the art.  
         [0035]     Should the authenticating information provided to USB peripheral  702  pass the validation performed by validation component  708 , a lock activation software component  712  is then executed. Lock activation component  712  contains program code for activating the mechanical mechanism for unlocking the cable lock.  
         [0036]     In a preferred embodiment, a software component  716  may be used to program USB peripheral  702  with a new password. Software component  716  may comprise a part of the operating system of host computer  700  or it may exist as a separate executable application. A user directs host computer  700  to execute software component  716 , which, after authenticating the user (using existing password  710 ), allows the user to enter a new password to be transmitted to USB peripheral  702  over USB connection  704 .  
         [0037]      FIG. 9  is a diagram wherein a process of unlocking a cable lock in accordance with a preferred embodiment of the present invention is presented in flowchart form. The embedded electronics contained within the cable lock apparatus first receives authentication information from a host computer (block  900 ). A determination is then made as to whether the received information authenticates the user as someone authorized to unlock the cable lock device, as per the authenticating information stored within the cable lock apparatus (block  902 ). If so (block  902 :Yes), additional instructions are executed that cause the lock to become unlocked (block  904 ), with the process terminating immediately thereafter. If the received information does not authenticate the user (block  902 :No), however, the process simply terminates.  
         [0038]      FIG. 10  is a block diagram illustrating the electronic hardware contained within a cable lock apparatus in accordance with a preferred embodiment of the present invention. A USB client device interface  1000  receives authenticating information and/or other commands or data from the host computer system. Other commands or data received from the host computer may include instructions to set or modify the password or other authentication information stored within the cable lock apparatus&#39; electronics. USB client interface  1000  also serves as a source of power to the cable lock apparatus electronics, since the USB standard allows for a host system to supply power to external USB peripherals through the physical USB interface.  
         [0039]     USB client interface feeds into a USB adapter/hub component  1002 , which is preferably implemented either as a portion of a monolithic integrated circuit or as a separate integrated circuit (IC) itself. A number of USB adapter ICs are available from various vendors. USB adapter/hub  1002  translates the USB interface signals from client interface  1000  into signals that are compatible with embedded processor/microcontroller  1006 . USB adapter/hub  1002  may also provide an additional USB host interface  1004  to allow additional USB peripherals (such as a mouse, for example) to be connected to USB adapter/hub  1002 . In the manner, the cable lock device described in  FIG. 9  may be connected to an available USB port on a host computer, but without reducing the number of available USB ports for use by other peripherals.  
         [0040]     Embedded processor/microcontroller  1006  is an embedded computer system that executes software for validating authentication information and initiating the mechanical unlock procedure. The process described in  FIG. 9  is carried out by software executed by embedded processor/microcontroller  1006 . Embedded processor/microcontroller  1006  will, in a preferred embodiment, contain (or at least be associated with) non-volatile memory for storing both the program code executed by embedded processor/microcontroller  1006  and any authentication information (such as a password) that may be required to validate authentication information received from the host computer. One of ordinary skill in the art will recognize that although a programmable microcontroller or processor is used in this preferred embodiment of the present invention, one may utilize dedicated (“hard wired”) circuitry to perform the same functions as embedded processor/microcontroller  1006  without departing from the scope and spirit of the present invention.  
         [0041]     Embedded processor/microcontroller  1006  is configured to activate and/or control motor/solenoid control/interface circuitry  1008 . Motor/solenoid control/interface circuitry  1008  is the electrical/electronic circuitry used to activate a solenoid  1010 , motor  1012 , or other electromechanical device. (depending on the particular embodiment) used to mechanically unlock the cable lock itself. A solenoid, such as solenoid  1010  consists of a coiled wire within which a rod or pin constructed of a ferromagnetic material positioned. When electrical current is applied to solenoid  1010 , the rod or pin is caused to retract, thus releasing the lock (this mechanism may be used in a padlock-type cable lock device, such as is depicted in  FIG. 1 , for example). Alternatively, an electric motor  1012  may be used to obtain rotational motion necessary to release the lock (in the case of a plug-type cable lock device as described in  FIG. 2 , for example).  
         [0042]      FIG. 11  is a block diagram of an exemplary host computer system that may be used in conjunction with a cable lock apparatus constructed in accordance with a preferred embodiment of the present invention to unlock the cable lock apparatus.  
         [0043]      FIG. 11  illustrates information handling system  1101  which is a simplified example of a computer system capable of performing the computing operations of the host computer described herein with respect to a preferred embodiment of the present invention. Computer system  1101  includes processor  1100  which is coupled to host bus  1102 . A level two (L 2 ) cache memory  1104  is also coupled to host bus  1102 . Host-to-PCI bridge  1106  is coupled to main memory  1108 , includes cache memory and main memory control functions, and provides bus control to handle transfers among PCI bus  1110 , processor  1100 , L 2  cache  1104 , main memory  1108 , and host bus  1102 . Main memory  1108  is coupled to Host-to-PCI bridge  1106  as well as host bus  1102 . Devices used solely by host processor(s)  1100 , such as LAN card  1130 , are coupled to PCI bus  1110 . Service Processor Interface and ISA Access Pass-through  1112  provides an interface between PCI bus  1110  and PCI bus  1114 . In this manner, PCI bus  1114  is insulated from PCI bus  1110 . Devices, such as flash memory  1118 , are coupled to PCI bus  1114 . In one implementation, flash memory  1118  includes BIOS code that incorporates the necessary processor executable code for a variety of low-level system functions and system boot functions.  
         [0044]     PCI bus  1114  provides an interface for a variety of devices that are shared by host processor(s)  1100  and Service Processor  1116  including, for example, flash memory  1118 . PCI-to-ISA bridge  1135  provides bus control to handle transfers between PCI bus  1114  and ISA bus  1140 , universal serial bus (USB) functionality  1145 , power management functionality  1155 , and can include other functional elements not shown, such as a real-time clock (RTC), DMA control, interrupt support, and system management bus support. Nonvolatile RAM  1120  is attached to ISA Bus  1140 . Service Processor  1116  includes JTAG and I2C buses  1122  for communication with processor(s)  1100  during initialization steps. JTAG/I2C buses  1122  are also coupled to L 2  cache  1104 , Host-to-PCI bridge  1106 , and main memory  1108  providing a communications path between the processor, the Service Processor, the L 2  cache, the Host-to-PCI bridge, and the main memory. Service Processor  1116  also has access to system power resources for powering down information handling device  1101 .  
         [0045]     Peripheral devices and input/output (I/O) devices can be attached to various interfaces (e.g., parallel interface  1162 , serial interface  1164 , keyboard interface  1168 , and mouse interface  1170  coupled to ISA bus  1140 . Alternatively, many I/O devices can be accommodated by a super I/O controller (not shown) attached to ISA bus  1140 .  
         [0046]     In order to attach computer system  1101  to another computer system to copy files over a network, LAN card  1130  is coupled to PCI bus  1110 . Similarly, to connect computer system  1101  to an ISP to connect to the Internet using a telephone line connection, modem  1175  is connected to serial port  1164  and PCI-to-ISA Bridge  1135 .  
         [0047]     While the computer system described in  FIG. 10  is capable of executing the processes described herein, this computer system is simply one example of a computer system. Those skilled in the art will appreciate that many other computer system designs are capable of performing the processes described herein.  
         [0048]     One of the preferred implementations of the invention is a client application, namely, a set of instructions (program code) or other functional descriptive material in a code module that may, for example, be resident in the random access memory of the computer. Until required by the computer, the set of instructions may be stored in another computer memory, for example, in a hard disk drive, or in a removable memory such as an optical disk (for eventual use in a CD ROM) or floppy disk (for eventual use in a floppy disk drive), or downloaded via the Internet or other computer network. Thus, the present invention may be implemented as a computer program product for use in a computer. In addition, although the various methods described are conveniently implemented in a general purpose computer selectively activated or reconfigured by software, one of ordinary skill in the art would also recognize that such methods may be carried out in hardware, in firmware, or in more specialized apparatus constructed to perform the required method steps. Functional descriptive material is information that imparts functionality to a machine. Functional descriptive material includes, but is not limited to, computer programs, instructions, rules, facts, definitions of computable functions, objects, and data structures.  
         [0049]     While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects. Therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. Furthermore, it is to be understood that the invention is solely defined by the appended claims. It will be understood by those with skill in the art that if a specific number of an introduced claim element is intended, such intent will be explicitly recited in the claim, and in the absence of such recitation no such limitation is present. For non-limiting example, as an aid to understanding, the following appended claims contain usage of the introductory phrases “at least one” and “one or more” to introduce claim elements. However, the use of such phrases should not be construed to imply that the introduction of a claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an;” the same holds true for the use in the claims of definite articles.

Summary:
A cable lock apparatus that is operated by the computer equipment that the apparatus is intended to protect, rather than by a key, is disclosed. According to a preferred embodiment of the invention, the cable lock is equipped with a hot-swappable computer interface, such as a Universal Serial Bus (USB) interface, for connecting to the computer. The user of the computer unlocks the cable lock by providing a password or other form of authentication to the computer. The computer transmits this authentication information, via the USB interface, to circuitry within the cable lock device, which validates the authentication information. If the authentication information validates properly, the cable lock device circuitry activates a motor or solenoid to mechanically release the cable lock.