Abstract:
A Flash-interfaced Fingerprint Sensor is disclosed. The sensor device interfaces directly with a flash memory interface chip. The flash memory interface chip incorporates the system for interfacing with flash memory devices, a fingerprint sensor/detector system, and an encryption subsystem for encrypting data being passed to and from the flash memory devices and the host computing device. The device further employs an advanced encryption approach that entails fingerprint decryption and verification on the host computer rather than on the portable memory apparatus. Once verification at the host computer is complete, memory and host functionality is enabled.

Description:
[0001]     This application is filed within one year of, and claims priority to Provisional Application Ser. No. 60/613,842, filed Sep. 27, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     This invention relates generally to fingerprint sensors and related devices and, more specifically, to a Flash-interfaced Fingerprint Sensor.  
         [0004]     2. Description of Related Art  
         [0005]     Miniature portable electronic storage devices have advanced substantially in recent years. An extremely popular version is the USB flash drive.  FIG. 1  is an exploded perspective view of a conventional USB flash drive  10 . The Conventional USB Flash Drive  10 , which many times is configured to be attached to a person&#39;s keychain, is roughly the size of a package of gum and is defined by a Housing  12  from which a USB Plug  14  extends, with a Cap  16  typically included to protect the Plug  14 . This Conventional Drive  10  is used generally to permit the easy storing and transfer of electronic files. The user simply inserts the USB Plug  14  into the appropriate receptacle on a host computer and the computer&#39;s operating system generally will discover the new addition and will then allow the user to access the memory on the Flash Drive  10  just as the user would access any other storage device associated with the computer. If we now turn to  FIG. 2 , we can examine the main components of the Conventional Flash Drive  10 .  
         [0006]      FIG. 2  is a block diagram of the conventional USB flash drive of  FIG. 1 . Within the Housing  12  is a Circuit Substrate  20 , which is typically a conventional PC board. On the Circuit Substrate  20  a plurality of Flash Memory Devices  24  are attached and electrically connected. A Flash Interface Device  22  controls access to the Memory Devices  24  by the External Computing Device  18  such as a host personal computer.  
         [0007]     The Flash Memory Devices  24  are available in different sizes, and furthermore the number of Devices  24  included in the Flash Drive  10  can be varied in order to provide the amount of memory that is desired by the manufacturer. Turning to  FIG. 3 , we can examine how the Flash Drive  10  operates.  
         [0008]      FIG. 3  depicts the functional orientation of the drive of  FIGS. 1 and 2  relative to a host computing device. As shown here, there are four Flash Memory Devices  24 A,  24 B,  24 C and  24 D. Each of these Devices  24  communicates directly with the USB Flash Interface Device  22 . The Interface Device  22  is designed to control access to the Memory Devices  24  from any outside system. The Device  22  may include the ability to encrypt and/or password protect access to the Memory Devices  24 . The USB Flash Interface Device  22  then communicates with the USB Host Interface Device  26  that is contained within the External Computing Device  18 . Within the Computing Device  18  there will also be Driver Software Applications  28  that enable the functionality of the USB Flash Drive  10 , including some encryption and/or password protection capabilities associated with the USB Flash Interface Device  22 .  
         [0009]     In an effort to further secure the data contained within the Conventional USB Flash Drive, one manufacturer incorporated a Fingerprint Sensor Device  32 .  FIG. 4  depicts a system incorporating this device.  FIG. 4  is a block diagram of a conventional fingerprint-sensing USB flash drive  30 . The Conventional Fingerprint Sensing USB Flash Drive  30  comprises a Housing and USB Flash Interface, but in this case the Flash Interface Device  23  has specialized capabilities in order to enable it to interface with the Microcontroller Fingerprint Sensor Device  32  that is used in this Drive  30 . Furthermore, because the Fingerprint Sensor Device  32  and Specialized Flash Interface Device  23  would otherwise be an incompatible with the conventional circuit substrate, a Specialized Circuit Substrate  21  must be used for this Fingerprint Sensing USB Flash Drive  30 .  
         [0010]     The Microcontroller Fingerprint Sensor Device  32  has two main parts; the Fingerprint Sensor System  34  and the Microcontroller Interface  36 . If we now turn to  FIG. 5 , we can discuss the operation of this Drive  30 .  
         [0011]      FIG. 5  depicts the functional orientation of the drive of  FIG. 4  relative to a host computing device. As shown here, each of the Flash Memory Devices  24 , rather than communicating directly with the USB Flash Interface Device  23 , instead communicate directly with the Microcontroller Fingerprint Sensor Device  32 . Specifically, the Microcontroller Interface portion  36  of the Device  32  operates to accept fingerprints that are sensed by the Sensor System  34  and then determine whether or not access will be granted to the Devices  24  via the USB Flash Interface  23 . If access is granted, then the USB Host Interface  26  will be allowed access and the Driver Applications  28  will also be allowed to access to the Flash Memory Devices  24 .  
         [0012]     The problem with this prior system is that it is so customized in its design, that beyond the conventional flash memory devices, virtually every component within the drive is custom. As a result, this device can never be cost competitive with a non-fingerprint sensing USB drive and furthermore is unlikely to be economically feasible. What is needed is a low-cost way of converting conventional USB flash drive architecture to add fingerprint sensing capability.  
       SUMMARY OF THE INVENTION  
       [0013]     In light of the aforementioned problems associated with the prior devices and methods, it is an object of the present invention to provide a Flash-interfaced Fingerprint Sensor. The sensor should interface directly with a flash memory interface chip. The flash memory interface chip should incorporate the system for interfacing with flash memory devices, a fingerprint sensor/detector system, and an encryption subsystem for encrypting data being passed to and from the flash memory devices and the host computing device. The device should further employ an advanced encryption approach that entails fingerprint decryption and verification on the host computer rather than on the portable memory apparatus. Once verification at the host computer is complete, memory and host functionality should be enabled.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which:  
         [0015]      FIG. 1  is an exploded perspective view of a conventional USB flash drive;  
         [0016]      FIG. 2  is a block diagram of the conventional USB flash drive of  FIG. 1 ;  
         [0017]      FIG. 3  depicts the functional orientation of the drive of  FIGS. 1 and 2  relative to a host computing device;  
         [0018]      FIG. 4  is a block diagram of a conventional fingerprint-sensing USB flash drive;  
         [0019]      FIG. 5  depicts the functional orientation of the drive of  FIG. 4  relative to a host computing device;  
         [0020]      FIG. 6  is an exploded perspective view of a USB flash drive incorporating a preferred embodiment of the flash-interfaced fingerprint sensor of the present invention;  
         [0021]      FIG. 7  is a block diagram of the USB drive of  FIG. 6 ;  
         [0022]      FIG. 8  depicts the functional orientation of the drive of  FIGS. 6 and 7 ; and  
         [0023]      FIG. 9  is a flowchart depicting the fingerprint recognition method utilized by the flash-interfaced fingerprint sensor of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a Flash-interfaced Fingerprint Sensor.  
         [0025]     The present invention can best be understood by initial consideration of  FIG. 6 .  FIG. 6  is an exploded perspective view of a USB flash drive incorporating a preferred embodiment of the flash-interfaced fingerprint sensor of the present invention. The USB Flash Drive Having a Flash Interfaced Fingerprint Sensor  40  comprises a Housing  42 , a USB Plug  44  and a Cap  46  therefor, and a Flash Fingerprint Sensor  48  which is exposed so that the user can swipe his or her finger or thumb across its window. As you can see, the dimensions and shape of this USB Flash Drive  40  are identical to a conventional drive, the only difference being that there is a Fingerprint Sensor  48  disposed on the outer surface. If we now turn to  FIG. 7 , we can examine how this system operates.  
         [0026]      FIG. 7  is a block diagram of the USB drive of  FIG. 6 . In the Device  40 , the Housing  42  contains a circuit substrate to which a plurality of flash memory devices are electrically connected. Furthermore, a Conventional Flash Interface Device  22  is also electrically connected. The difference between the conventional device of  FIG. 1  and this device is that one of the Flash Memory Devices  24  has been removed and/or replaced with a Flash Fingerprint Sensor Device  50  of the present invention. The Flash Fingerprint Device  50  comprises three functional components: the Fingerprint Sensor System  48  which is configured to obtain a user&#39;s fingerprint; an Encryption Subsystem  54  which, as will be discussed further below, manipulates the received fingerprint data; and the final element being a Flash Interface Subsystem  52  which converts data transmitted or being received by the Flash Fingerprint Sensor Device  50  into a format that matches a Conventional Flash Memory Device  24 . As a result, no modification is necessary for the Circuit Substrate  20  or the Flash Interface Device  22 . In fact, if the fingerprint sensor features of this invention were disabled, the Drive  40  would operate just like a conventional USB flash drive. A further result of this novel approach of converting conventional architecture to provide new functionality is that extremely good cost benefits have been experienced while still providing substantial added functionality. Turning to  FIG. 8 , we can examine how the system operates.  
         [0027]      FIG. 8  depicts the functional orientation of the drive of  FIGS. 6 and 7 . As shown here, and as discussed previously, the Flash Fingerprint Sensor Device  50  has been installed in place of an available location for a Flash Memory Device  24 . The Fingerprint Sensor System  48  communicates with an Encryption System  54 , which in turn communicates through a Flash Interface Subsystem  52  with a conventional USB Flash Interface  22 . As shown, each of the Flash Memory Devices  24 A,  24 B and  24 C all communicate directly with the USB Flash Interface  22 . As will be discussed further in connection with  FIG. 9 , the control of access to the Flash Memory Devices  24  is handled by a combination of functions executed by the USB Flash Interface  22  and a Driver Application  29  located on the External Computing Device  18 . If we now turn to  FIG. 9 , we can discuss how such operation occurs.  
         [0028]      FIG. 9  is a flowchart depicting the fingerprint recognition method utilized by the flash-interfaced fingerprint sensor of the present invention. The Flash Fingerprint Recognition Method  60  of the present invention commences when the Fingerprint Sensor System  48  receives Fingerprint Data  100 . The data is received by the user scanning his or her finger or thumb into the Fingerprint Sensor  48 . The received fingerprint Data is then Buffered  102  in order to provide sufficient time for the Data to be Encrypted  104  and/or scrambled. Any time Fingerprint Data is Received  100  (i.e. when data is transmitted by the Fingerprint Sensor System  48 ) a Key is Generated and Transmitted  106  by the Encryption Subsystem  54 . Once the Key is Generated and Transmitted  106 , the encrypted Fingerprint Data is then Transmitted  108 . This encrypted data is transmitted via the Flash Interface Subsystem  52 , the USB Flash Interface  22  and the USB Host Interface  26  until it reaches the Host Computer Driver Application  29 , which is specially configured to operate cooperatively with the Encryption Subsystem  54 .  
         [0029]     The Driver Application  29  decrypts or at least attempts to Decrypt the Encrypted Fingerprint Data  110 . Of course, if the application fails to decrypt the data, such as because the data has been tampered with or encrypted improperly, then the Method  60  will stop here. If the Data is decrypted, however, the application will compare the decrypted fingerprint data against the resident data for the authorized user or users. If the Fingerprint Data is Recognized  112 , then the Driver Application  29  will enable permissive USB and/or Host Functionality  114 . If the data is not recognized, then this permissive functionality will Not be Enabled  1   16 .  
         [0030]     An example of permissive USB functionality being enabled is that condition where normal USB flash drive access is possible; the user can save and retrieve data to and from the flash memory devices. What is unique here is that this system enables the addition of new host computer functionality as well. In fact, the system of the present invention could be configured to actually operate as a fingerprint-activated access key to the host computer. This means that the host computer would be locked until such time as the fingerprint data is recognized by the Driver Application  29 . Since this device uses a standard USB interface, it is a simple Software Application  29  that provides this host computer lock functionality. Of course, both the USB permissive functionality and the host computer permissive functionality could be enabled or disabled together or after requiring separate levels of permission.  
         [0031]     In summary, there are two significant distinctions between the Method  60  depicted here and that used by the Microprocessor-based Fingerprint Sensor Drive. Here there is unidirectional authentication. This means that the user&#39;s finger or thumbprint is authenticated without a challenge and reply process. Either the received data matches and is recognized by the database of authorized user data that is resident on the host computer, or functionality is not enabled. Since this is unidirectional, it will operate quickly and with very little user interface. A further distinction is that the host decrypts the encrypted fingerprint data. On the prior microprocessor-controlled system, all fingerprint data encryption and decryption and authorization occurred within the USB flash device itself As discussed above, this adds substantial cost to the fingerprint sensor-enabled device to the point where it becomes completely economically unfeasible.  
         [0032]     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.