Abstract:
A multi-layer USB drive for storing data in a memory has at least two printed circuit board assemblies, each one including a memory for storing data and a control microprocessor controlling the flow of data to and from the memory. The circuit board assemblies are operatively connected to one another in a serial manner for exchange of data between adjacent assemblies upon access by a user and wherein at least one of the control microprocessors is security enabled requiring a user defined security input for accessing the memory of the printed circuit board assembly of that security enabled control microprocessor. A USB connector is for connecting to a USB slot of a device and the USB connector is operatively connected to only one of the printed circuit board assemblies. A USB hub is provided on at least one of the assemblies for recognizing the circuit board assemblies of the USB drive. An opaque housing completely encloses the circuit board assemblies preventing at least the printed circuit board assembly or assemblies other than the one connected to the USB connector from being viewed.

Description:
CLAIM OF PRIORITY 
     The priority of related Canadian Patent Application Serial No. 2,812,607, entitled “A Multi-Layer USB Storage Drive with Physically Separated Secure Storage Layer and Non Secure Storage Layer, and with Multiple Layers”, filed Apr. 2, 2013, is hereby claimed. 
     FIELD OF THE INVENTION 
     This invention relates to improvements to data security contained in the memory of USB storage devices and other mobile storage devices, including USB Flash Drives (or USB Pen Drives), USB Hard Drives, USB Media Cards (or Memory Cards), USB Media Cards (or Memory Cards Readers) through media card reader controller. Hard Drive can be of various forms, including traditional IDE Hard Drive, SATA Hard Drive, SCSI Hard Drive, or advanced SSD—Solid State Flash Drive. Media Cards can include SD—Secure Digital Cards, MMC—Multimedia Cards, CF—CompactFlash Cards, MS—Memory Sticks, xD—Extreme Digital Picture Cards, and the like. 
     The invention is directed to a Multi-Layer USB Drive (sometimes referred to herein as a MLUD) device connectable to a computer system through a USB port to operate as a portable storage device. The MLUD is configured to make it difficult to locate and to access secure data stored on the device and to permit a variety of security features (or sometimes no security) at different levels (or layers) of printed circuit board assemblies within a single MLUD. The complete Multi-Layer USB Drive (MLUD) is comprised of two or more printed circuit board assemblies (sometimes referred to herein as PCBAs) connected and housed together. 
     BACKGROUND 
     The security of data contained in portable storage devices is a significant concern among users of those devices and security personnel charged with maintaining the security of sensitive information. The problem is exacerbated by the development of small storage devices which are portable and are therefore more susceptible to loss and theft. In recent years there have been many examples of security breaches when sensitive data contained on portable data storage devices are stolen or mislaid and then publicly released. With the ubiquitous nature of the Internet sensitive data lost or stolen can easily and quickly be disseminated throughout the world before steps can be taken to contain that dissemination. Once that information is leaked to the Internet it is often impossible to contain it. The release of this sensitive data can cause considerable hardship and liability to those entrusted with the care and security of that data. 
     To mitigate against the unauthorised disclosure of sensitive data protective measure have been employed, including password protection, finger print recognition, locking mechanisms and so on. However there is a need for further security enhancements to USB memory devices to reduce the risk of security breaches and unauthorized use or dissemination of sensitive data. 
     SUMMARY OF THE INVENTION 
     Applicant has developed a system for securing sensitive information on USB memory devices by employing a Multi-Layer USB Drive having two or more printed circuit board assemblies connected in series. Access is initially granted to a user to the first PCBA. Access to additional PCBAs occurs only after a user is aware of and follows certain access protocols to access successive PCBAs connected in series to the first or initial PCBA. Additional PCBAs can also be connected and accessed successively based on knowledge of their existence by a user and implementing the correct access protocol. Even if that knowledge exists and the access protocol implemented, additional security features can be employed in order to provide additional security as to unauthorised access, such as password protection, fingerprint recognition, data encryption, DRM (Digital Rights Management), security tokens, data masking, anti-virus software and/or other protective features. The Multi-Layer USB Drive (MLUD), with its the two or more PCBAs, is contained within one housing to reduce the opportunity for unauthorised users to gain the knowledge that further PCBAs, in addition to the initial or first PCBA, are contained with the housing. 
     Applicant&#39;s Multi-Layer USB Drive can be configures so that the more sensitive the data the further that data is stored from the initial PCBA. In a MLUD with three PCBAs, for example, the initial or first PCBA could have no security features, and would contain data not considered of a sensitive or confidential nature. The next PCBA connected in series could include a more simpler protocol for access such as an icon visible on the screen to be mouse-clicked to access that second level PCBA. That second level PCBA could contain data of a sensitive or confidential nature and access could be further protected by a password. And the third PCBA, connected in series to the second PCBA could contain the most sensitive data and have the highest level of protection. This could be by touch screen access protocol requiring the touching of certain pre-determined points on the screen in a predetermined order. And then requiring a user to pass through a security token system to access the data. 
     In the event of loss or theft leading to an attempt to access the data, many unauthorised users may not even be aware that anything other than the initial or first PCBA exists within the housing of the USB memory device. Sensitive data in other PCBAs connected in series is never accessed as there is no knowledge of their existence. And even in the event that the second level PCBA is accessed, the additional protection of a password, or other security feature can prevent access to the data on the second level PCBA. 
     As a further optional feature of applicant&#39;s invention sensitive data contained in any level of the Multi-Layer USB Drive could be deleted remotely under the instruction of a Central Database Server (CDS) which has been configured with management functions in respect of the Multi-Layer USB Drive. 
     Applicant&#39;s invention is directed to a Multi-Layer USB Drive comprised of three major portions, an outer housing or case, at least two USB Drive PCBAs and a typical USB connector. The PCBAs (printed circuit board assemblies) are comprised of one or more access and/or control features, including a USB control chip; a USB hub chip; a code generating chip; and various other security chips (such as a fingerprint recognition chip), flash memory, and other parts common to typical USB memory devices and well known in the art. The combination provides added security to the storage regions of second and higher levels of PCBAs in the housing as will be discussed herein. 
     As a further feature one or more PCBAs include a USB Hub chip to enable the linking of multiple levels within the drive, each level acting as a separate USB drive. A general connector of a type familiar to those skilled in the art is used to physically connect the drives. 
     Applicant&#39;s Multi-Layer USB Drive (MLUD) could also be used for other types of USB storage devices and memory cards such as USB Hard Drives, SD cards, micro SD cards, mini SD cards, MMC cards, MMC micro cards, MS cards, MS Duo cards, CF cards, PCMCIA cards, xD cards, etc. 
     Advantages 
     Several advantages have been identified for applicant&#39;s Multi-Layer USB Drive (MLUD):
         1. Confidential digital data content can be protected physically by storing the data at a higher level of PCBAs requiring that unauthorized users pass through several layers of security to access that sensitive content.   2. The existence of confidential digital data content stored at a level higher than the first level of PCBA can be hidden from users by masking the existence of the higher level PCBAs.   3. The existence of confidential digital data content stored at a level higher than the first level of PCBA can be made difficult to users by including an innocuous icon for accessing higher level PCBAs, so that unauthorized users have difficulty recognizing the icon as an entryway to the higher level PCBAs.   4. With proper configuration of a Code Generating Control (CGC) chip at a level of the PCBA, access to the next higher level can only be accessed upon entry of the code assigned by the CGC.   5. The secured memory and the non-secured memory of the Multi-Layer USB Drive (MLUD) are physically separated, as compared to systems where secured portions are separated from non-secured portions by means of software in the same memory. Thus the secured portion can be physically secured with a greater level of security as compared to software based separation within the same memory.   6. Each PCBA can be configured with different features, including different storage capacities, as desired by the manufacturer. One layer doesn&#39;t have to be the same as another in storage capacity. Each layer can be configured as protected or unprotected, thus providing flexibility for configuring the PCBAs of the MLUD.   7. The Multi-Layer USB Drive (MLUD) with a CGC chip can be registered to a central database server (CDS) which could link the MLUD through the Internet or other network. The CDS can be configured to send instructions to securely and remotely delete or update the content of a MLUD. This management function could be designed to control the MLUD on a level by level basis.   8. As the Multi-Layer USB Drive (MLUD) has multiple PCBAs, each PCBA could have different security features such as password protection, fingerprint security, encryption, etc. This can often make it more difficult to access data stored in higher PCBA levels of the MLUD.       

     In conclusion, as the Multi-Layer USB Drive (MLUD) includes multiple PCBAs, it can be configured with different number of PCBAs, and each PCBA can be configured with different or the same storage size and security features, including the option of having no security feature at a desired PCBA. A CDS can control each PCBA, or any number of them, remotely for flexibility of remote control. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of internal components of a USB storage device of the prior art with non-secured storage; 
         FIG. 2  is a schematic view of internal components of a USB storage device of the prior art with secured storage; 
         FIG. 3  is a schematic view of internal components of a USB storage device of the prior art with non-secured storage and a code generating chip; 
         FIG. 4  is a schematic view of internal components of a USB storage device of the prior art with secured storage and a code generating chip; 
         FIG. 5  is a schematic view of internal components of a USB storage device of the prior art with non-secured storage and a USB hub chip; 
         FIG. 6  is a schematic view of internal components of a USB storage device of the prior art with secured storage and a USB hub chip; 
         FIG. 7  is a schematic view of internal components of a USB storage device of the prior art with non-secured storage, a USB hub chip and a code generating chip; 
         FIG. 8  is a schematic view of internal components of a USB storage device of the prior art with secured storage, a USB hub chip and a code generating chip (CGC); 
         FIG. 9  is a schematic view of internal components of a USB storage device of the prior art with secured storage, a code generating chip, a fingerprint chip, and a fingerprint scanner connector; 
         FIG. 10  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD) of the present invention with a non-secured storage printed circuit board assembly of  FIG. 5  as the initial PCBA and a secured storage printed circuit board assembly of  FIG. 4  as a higher level PCBA, connected in series in side by side orientation. 
         FIG. 11  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD) of the present invention with a non-secured storage printed circuit board assembly of  FIG. 5  as the initial PCBA and a secured storage printed circuit board assembly of  FIG. 4  as a higher level PCBA, connected in series with the assembly of  FIG. 4  oriented above the assembly of  FIG. 5 . 
         FIG. 12  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD) of the present invention with a non-secured storage printed circuit board assembly of  FIG. 5  as the initial PCBA, a secured storage printed circuit board assembly of  FIG. 4  as a higher level PCBA, and a secured storage printed circuit board assembly of  FIG. 9  as yet a higher level PCBA, connected in series with the assembly of  FIG. 9  oriented above the assembly of  FIG. 4  and the assembly of  FIG. 4  oriented above the assembly of  FIG. 5 . 
         FIG. 13  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD) of the present invention with a secured storage printed circuit board assembly of  FIG. 6  as the initial PCBA, a non-secured storage printed circuit board assembly of  FIG. 1  as a higher level PCBA, and a secured storage printed circuit board assembly of  FIG. 9  as yet a higher level PCBA, connected in series with the assembly of  FIG. 9  oriented above the assembly of  FIG. 1  and the assembly of  FIG. 1  oriented above the assembly of  FIG. 6 . 
         FIG. 14  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD) of the present invention with a secured storage printed circuit board assembly of  FIG. 8  as the initial PCBA, a secured storage printed circuit board assembly of  FIG. 4  as a higher level PCBA, and a secured storage printed circuit board assembly of  FIG. 9  as yet a higher level PCBA, connected in series with the assembly of  FIG. 9  oriented above the assembly of  FIG. 4  and the assembly of  FIG. 4  oriented above the assembly of  FIG. 8 . 
         FIG. 15  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD) of  FIG. 12  with a housing with a fingerprint scanner depicted. 
         FIG. 16  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD) of the present invention with a non-secured storage printed circuit board assembly of  FIG. 5  as the initial PCBA and a secured storage printed circuit board assembly of  FIG. 4  as a higher level PCBA, connected in series with the assembly of  FIG. 4  oriented above the assembly of  FIG. 5 . Shown schematically is the serial flow of data through the MLUD on access. 
         FIG. 17  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD) of  FIG. 12  with a housing with a fingerprint scanner depicted. Shown schematically is the serial flow of data through the MLUD on access. 
         FIG. 17-1  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD) of the present invention with a non-secured storage printed circuit board assembly of  FIG. 5  as the initial PCBA, a first secured storage printed circuit board assembly of  FIG. 4  as a higher level PCBA, a second secured storage printed circuit board assembly of  FIG. 4  as a higher level PCBA, and a secured storage printed circuit board assembly of  FIG. 9  as yet a higher level PCBA, connected in series with the assembly of  FIG. 9  oriented above the two assemblies of  FIG. 4  and the two assemblies of  FIG. 4  oriented above the assembly of  FIG. 5 . 
         FIG. 18  is a Flow Chart of the Serialized Data Access flow of Multi-Layer USB Drive (MLUD) of  FIG. 17 . 
         FIG. 19  is schematic view of internal components of the Multi-Layer USB Drive (MLUD), with a non-secured storage printed circuit board assembly of  FIG. 5 , a secured storage printed circuit board assembly of  FIG. 4 , and a secured storage printed circuit board assembly of  FIG. 9 , connected in parallel with the USB connector. 
         FIG. 20  is a Flow Chart of the Parallelized Data Access flow of Multi-Layer USB Drive (MLUD) of  FIG. 19 . 
         FIG. 21  is schematic view of internal components of the Multi-Layer USB Drive (MLUD) of  FIG. 17  for operative connection with a central database server to control the Multi-Layer USB Drive (MLUD) of  FIG. 17  and its function, through wired or remote connection. 
         FIG. 22  is a schematic view of a screen display showing the control parameters of the printed circuit board assemblies of  FIGS. 5 and 9 . 
         FIG. 23  are two schematic views of alternate exemplary storage systems to which the invention can be applied, an SD card with two flash storage drives and a portable hard drive with two hard disk storage drives. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention provides improved functionality and security to USB memory devices, including USB drives (or USB mobile drives), Memory Stick, Memory Card and other portable data storage drives. Applicant&#39;s Multi-Layer USB Drive (MLUD), provides physical security of digital data content with multiple independent and variable security levels among several printed circuit board assemblies. 
     This Multi-Layer USB Drive (MLUD) will store and secure the sensitive data on the physical hardware Multi-Layer Drives which could have their own independent security functions inside of a USB portable Drive. 
       FIGS. 1 through 9  are schematic views of internal components of typical prior art USB drives of various configurations, as described herein. The internal components are described herein generally as a printed circuit board assembly (sometimes referred to herein as a PCBA). The PCBA of  FIGS. 1 through 9  include the following components common in each printed Circuit board assembly. 
     Referring to  FIG. 1  as an example, USB storage device with PCBA  100  is shown. USB connector  50  is of typical dimension for insertion into the USB port of a computer or other electronic device to permit the flow of data between the USB storage device and the computer or other electronic device. USB connector is connected to the circuit board  52  of PCBA  100  to permit data flow between them. Several additional components  54  required for operability of PCBA  100  are shown generally and schematically, it being understood that those skilled in the art would select appropriate additional components as a matter of routine. It will also be understood that the underside of circuit board  52  (not shown) contains electrical connections to permit electrical communication between components of PCBA  100 . PCBA  100  further includes flash memory  15  where data may be received, stored and sent. 
     Distinctions between the printed circuit board assemblies of  FIGS. 1 through 9  will be discussed. 
       FIG. 1  is a schematic view of internal components of PCBA  100  of the prior art with non-secured storage with non-security USB control chip  11 . Data may be stored in and retrieved from flash memory  15  without the user having to pass through security measures on PCBA  100 . 
       FIG. 2  is a schematic view of internal components of PCBA  200  of the prior art with secured storage by means of security USB control chip  12 . Data may only be stored in and retrieved from flash memory  15  by a user who has successfully passed through a security requirement such as a user name and password. 
       FIG. 3  is a schematic view of internal components of PCBA  300  of the prior art with non-secured storage having non security USB control chip  11  and code generating chip  13 . Data may only be stored in and retrieved from flash memory  15  by a user who has successfully passed through security requirement of reproduction of a code generated by the code generating chip  13 . 
       FIG. 4  is a schematic view of internal components of PCBA  400  of the prior art with secured storage and a code generating chip by means of code generating chip  13  and security USB control chip  12 , which control the USB function with security such as, for example encryption or a user name and password. Data may only be stored in and retrieved from flash memory  15  by a user who has successfully passed through both a security requirement of reproduction of a code generated by the code generating chip  13  and a security requirement such as a user name and password. 
       FIG. 5  is a schematic view of internal components of PCBA  500  of the prior art with non-secured storage and a USB hub chip by means of non-security USB control chip  11 , which control the USB function without security. USB hub chip  14  is provided for use in the invention as will be described. Data may be stored in and retrieved from flash memory  15  without the user having to pass through security measures on PCBA  500 . 
       FIG. 6  is a schematic view of internal components of PCBA  600  of the prior art with secured storage and a USB hub chip by means of USB hub chip  14  and security USB control chip  12 . USB hub chip  14  is provided for use in the invention as will be described. Data may only be stored in and retrieved from flash memory  15  by a user who has successfully passed through a security requirement such as a user name and password. 
       FIG. 7  is a schematic view of internal components of PCBA  700  of the prior art with non-secured storage, by means of non-security USB control chip  11 , a USB hub chip  14  and a code generating chip  13 . USB hub chip  14  is provided for use in the invention as will be described. Data may only be stored in and retrieved from flash memory  15  by a user who has successfully passed through a security requirement of reproduction of a code generated by the code generating chip  13 . 
       FIG. 8  is a schematic view of internal components of PCBA  800  of the prior art with secured storage by means of security USB control chip  12 , a USB hub chip  14  and a code generating chip  13 . USB hub chip  14  is provided for use in the invention as will be described. Data may only be stored in and retrieved from flash memory  15  by a user who has successfully passed through a security requirement of reproduction of a code generated by the code generating chip  13  and who has successfully passed through a security requirement such as a user name and password. 
       FIG. 9  is a schematic view of internal components of PCBA  900  of the prior art with secured storage by means of security USB control chip  12 , a code generating chip  13 , a fingerprint chip  18 , and a fingerprint scanner connector  19 . Data may only be stored in and retrieved from flash memory  15  by a user who has successfully passed through a security requirement of reproduction of a code generated by the code generating chip  13 , who has successfully passed through a security requirement controlled by the USB control chip  12  such as a user name and password, and by matching a fingerprint using fingerprint chip  18  and a fingerprint scanner connector  19 . 
     A preferred embodiments of applicants invention will now be discussed with reference to  FIGS. 10 through 23  based on the USB storage devices of  FIGS. 1 through 9 . 
       FIG. 10  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD)  70  of the present invention with a non-secured storage printed circuit board assembly  500  of  FIG. 5  as the initial printed circuit board assembly and a secured storage printed circuit board assembly  400  of  FIG. 4  as a higher level printed circuit board assembly, connected in series in linear adjacent or end to end orientation. PCBA  500  is connected to USB connector  50  for operative connection to a USB connection of a computer or other electronic device. PCBA  500  has non-secured storage by means of non-security USB control chip or microprocessor  11 . 
     USB hub chip  14  of PCBA  500  expands the single USB connection of USB connector with computer  40  ( FIG. 21 ), or other USB reading electronic device, into multiple USB connections which connect PCBA  500  and  400  of drive  70  together. USB hub chip  14  may also be used in other embodiments to connect further printed circuit board assemblies with one connection between USB connector  50  and computer  40 . In addition USB hub chip  14  could provide connection information to control microprocessor  11  of PCBA  500  and to control microprocessor  12  of PCBA  400  to make the microprocessors aware of the existence of PCBA  500  and  400  of drive  70 , and optionally prioritize the display of data between them. 
     A user may obtain data from flash memory  15  without the entry of a password or other security means. PCBA  400  is connected to the end of PCBA  500  opposite to the end connected to connector  50 , for exchange of data serially through control chip  11  of PCBA  500 . Access to flash memory  15  of PCBA  400  is controlled through USB control chip  12  and code generating chip  13 . Data may only be stored in and retrieved from flash memory  15  of PCBA  400  by a user who has successfully passed through a security requirement of reproduction of a code generated by the code generating chip  13  and who has successfully passed through a security requirement controlled by the USB control chip  12 , such as a user name and password. 
       FIG. 11  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD)  80  of the present invention with a non-secured storage printed circuit board assembly  500  of  FIG. 5  as the initial printed circuit board assembly and a secured storage printed circuit board assembly  400  of  FIG. 4  as a higher level PCBA, connected in series with the assembly of  FIG. 4  oriented above and connected to the assembly of  FIG. 5 . PCBA  500  is connected to USB connector  50  for operative connection to a USB connection of a computer or other electronic device. PCBA  500  has non-secured storage by means of non-security USB control chip or microprocessor  11 . 
     USB hub chip  14  of PCBA  500  expands the single USB connection of USB connector with computer  40  ( FIG. 21 ), or other USB reading electronic device, into multiple USB connections which connect PCBA  500  and  400  of drive  80  together. USB hub chip  14  may also be used in other embodiments to connect further printed circuit board assemblies with one connection between USB connector  50  and computer  40 . In addition USB hub chip  14  could provide connection information to control microprocessor  11  of PCBA  500  and to control microprocessor  12  of PCBA  400  to make the microprocessors aware of the existence of PCBA  500  and  400  of drive  80 , and optionally prioritize the display of data between them. 
     A user may obtain data from flash memory  15  without the entry of a password or other security means. PCBA  400  is connected to PCBA  500  in general alignment above PCBA  500  with operative electrical connection for exchange of data serially through control chip  11  of PCBA  500 . PCBA  400  has a female pin  17 - 1  and PCBA  500  has a male pin  17  for operative connection to female pin  17 - 1  of PCBA  400 . Male pin  17  of PCBA  500  is connected to female pin  17 - 1  of PCBA  400  to both secure PCBA  500  to PCBA  400  and also provide an electrical connection for exchange of data between controller  11  of PCBA  500  and controller  12  of PCBA  400 . Access to flash memory  15  of PCBA  400  is controlled through USB control chip  12  and code generating chip  13 . Data may only be stored in and retrieved from flash memory  15  of PCBA  400  by a user who has successfully passed through a security requirement of reproduction of a code generated by the code generating chip  13  and who has successfully passed through a security requirement controlled by the USB control chip  12 , such as a user name and password. 
       FIG. 12  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD)  90  of the present invention with a non-secured storage printed circuit board assembly  500  depicted in  FIG. 5  as the initial printed circuit board assembly, a secured storage printed circuit board assembly of PCBA  400  depicted in  FIG. 4  as a higher level PCBA, and a secured storage printed circuit board assembly of PCBA  900  depicted in  FIG. 9  as yet a higher level PCBA, connected in series with the assembly of  FIG. 9  oriented above and connected to the assembly of  FIG. 4  and the assembly of  FIG. 4  oriented above and connected to the assembly of  FIG. 5 . The connection and operations of devices  500  and  400  are the same as discussed above with respect to  FIG. 11 . 
     However USB hub chip  14  of PCBA  500  expands the single USB connection of USB connector with computer  40  ( FIG. 21 ), or other USB reading electronic device, into multiple USB connections which connect PCBA  500 ,  400  and  900  of drive  90  together. USB hub chip  14  may also be used in other embodiments to connect further printed circuit board assemblies with one connection between USB connector  50  and computer  40 . In addition USB hub chip  14  could provide connection information to control microprocessor  11  of PCBA  500 , to control microprocessor  12  of PCBA  400  and to control microprocessor  12  of PCBA  900  to make the microprocessors aware of the existence of PCBA  500 ,  400  and  900  of drive  90 , and optionally prioritize the display of data between them. 
     PCBA  900  is connected to PCBA  400  in general alignment above PCBA  400  with operative electrical connection for exchange of data serially through microprocessor  12  of PCBA  400 . PCBA  400  has two pins, male pin  17  and female pin  17 - 1  and PCBA  900  has a female pin  17 - 1 . Male pin  17  of PCBA  400  is connected to female pin  17 - 1  of PCBA  900  to both secure PCBA  900  to PCBA  400  and also provide an electrical connection for exchange of data between microprocessor  12  of PCBA  400  and microprocessor  12  of PCBA  900 . Data may only be stored in and retrieved from flash memory  15  of PCBA  900  by a user who has successfully passed through a security requirement of reproduction of a code generated by the code generating chip  13  of PCBA  900 , and who has successfully passed through a security requirement controlled by the USB control chip  12  of PCBA  900  such as a user name and password, and by matching a fingerprint using fingerprint chip  18  and a fingerprint scanner connector  19 , both of PCBA  900 . 
     As an option with a code generating chip  13 , user authentication could be verified without memory access. Further the generated code could be stored at the USB control chip  12  at the same time as in memory. The USB Control Chip  12  and Code Generating Chip  13  of PCBA  900  could do a cross check between the two chips, thereby providing additional security. 
       FIG. 13  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD)  91  of the present invention with a secured storage printed circuit board assembly of PCBA  600  depicted in  FIG. 6  as the initial printed circuit board assembly, a non-secured storage printed circuit board assembly of PCBA  100  depicted in  FIG. 1  as a higher level PCBA, and a secured storage printed circuit board assembly of PCBA  900  depicted in  FIG. 9  as yet a higher level PCBA, connected in series with the assembly of  FIG. 9  oriented above and connected to the assembly of  FIG. 1  and the assembly of  FIG. 1  oriented above and connected to the assembly of  FIG. 6 . PCBA  600  is connected to USB connector  50  for operative connection to a USB connection of a computer or other electronic device. 
     PCBA  100  is connected to PCBA  600  in general alignment above PCBA  600  with operative electrical connection for exchange of data serially through control chip  12  of PCBA  600 . PCBA  100  has a female pin  17 - 1  and PCBA  600  has a male pin  17  for operative connection to female pin  17 - 1  of PCBA  100 . Male pin  17  of PCBA  600  is connected to female pin  17 - 1  of PCBA  100  to both secure PCBA  600  to PCBA  100  and also provide an electrical connection for exchange of data between controller  12  of PCBA  600  and controller  11  of PCBA  100 . Access to flash memory  15  of PCBA  100  is controlled through USB control chip  11 . Data may only be stored in and retrieved from flash memory  15  of PCBA  100  by a user who has successfully passed through a security requirement controlled by the USB control chip  12  of PCBA  600 , such as a user name and password. No additional control for access to flash memory  15  of PCBA  100  is required as PCBA  100  is controlled by non-secure controller  11 . 
     PCBA  900  is connected to PCBA  100  in general alignment above PCBA  100  with operative electrical connection for exchange of data serially through control chip  11  of PCBA  100 . PCBA  100  has two pins, male pin  17  and female pin  17 - 1  and PCBA  900  has a female pin  17 - 1 . Male pin  17  of PCBA  100  is connected to female pin  17 - 1  of PCBA  900  to both secure PCBA  900  to PCBA  100  and also provide an electrical connection for exchange of data between controller  11  of PCBA  100  and controller  12  of PCBA  900 . Data may only be stored in and retrieved from flash memory  15  of PCBA  900  by a user who has successfully passed through a security requirement controlled by the USB control chip  12  of PCBA  600 , and a user who has successfully passed through a security requirement controlled by the USB control chip  12  of PCBA  900  such as a user name and password, and by matching a fingerprint using fingerprint chip  18  and a fingerprint scanner connector  19 , both of PCBA  900 . 
     USB hub chip  14  of PCBA  600  expands the single USB connection of USB connector with computer  40  ( FIG. 21 ), or other USB reading electronic device, into multiple USB connections which connect PCBA  600 ,  100  and  900  of drive  91  together. USB hub chip  14  may also be used in other embodiments to connect further printed circuit board assemblies with one connection between USB connector  50  and computer  40 . In addition USB hub chip  14  could provide connection information to control microprocessor  12  of PCBA  600 , to control microprocessor  11  of PCBA  100  and to control microprocessor  12  of PCBA  900  to make the microprocessors aware of the existence of PCBA  600 ,  100  and  900  of drive  91 , and optionally prioritize the display of data between them. 
       FIG. 14  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD)  92  of the present invention with a secured storage printed circuit board assembly of PCBA  800  depicted in  FIG. 8  as the initial PCBA, a secured storage printed circuit board assembly of PCBA  400  depicted in  FIG. 4  as a higher level PCBA, and a secured storage printed circuit board assembly of PCBA  900  depicted in  FIG. 9  as yet a higher level PCBA, connected in series with the assembly of  FIG. 9  oriented above and connected to the assembly of  FIG. 4  and the assembly of  FIG. 4  oriented above and connected to the assembly of  FIG. 8 . PCBA  800  is connected to USB connector  50  for operative connection to a USB connection of a computer or other electronic device. 
     PCBA  400  is connected to PCBA  800  in general alignment above PCBA  800  with operative electrical connection for exchange of data serially through control chip  12  of PCBA  800 . PCBA  400  has a female pin  17 - 1  and PCBA  800  has a male pin  17  for operative connection to female pin  17 - 1  of PCBA  400 . Male pin  17  of PCBA  800  is connected to female pin  17 - 1  of PCBA  400  to both secure PCBA  800  to PCBA  400  and also provide an electrical connection for exchange of data between controller  12  of PCBA  800  and controller  12  of PCBA  400 . Access to flash memory  15  of PCBA  400  is controlled through USB control chip  12  and code generating chip  13  of PCBA  800 . Data may only be stored in and retrieved from flash memory  15  of PCBA  400  by a user who has successfully passed through the security requirements of PCBA  800 , that being reproduction of a code generated by the code generating chip  13  and the security requirement controlled by the USB control chip  12 , such as a user name and password. 
     PCBA  900  is connected to PCBA  400  in general alignment above PCBA  400  with operative electrical connection for exchange of data serially through control chip  12  of PCBA  400 . PCBA  400  has two pins, male pin  17  and female pin  17 - 1  and PCBA  900  has a female pin  17 - 1 . Male pin  17  of PCBA  400  is connected to female pin  17 - 1  of PCBA  900  to both secure PCBA  900  to PCBA  400  and also provide an electrical connection for exchange of data between controller  12  of PCBA  400  and controller  12  of PCBA  900 . Data may only be stored in and retrieved from flash memory  15  of PCBA  900  by a user who has successfully passed through the security requirements controlled by PCBA  800 , then the security requirements controlled by PCBA  400 , and then a user who has successfully passed through the security requirement controlled by the USB control chip  12  of PCBA  900 . The security requirements of PCBA  800  are reproduction of a code generated by the code generating chip  13  and the security requirement controlled by USB control chip  12 , such as a user name and password. The security requirements of PCBA  400  are reproduction of a code generated by the code generating chip  13  and the security requirement controlled by the USB control chip  12 , such as a user name and password. The security requirements of PCBA  900  are reproduction of a code generated by the code generating chip  13 , the security requirement controlled by the USB control chip  12 , such as a user name and password, and by matching a fingerprint using fingerprint chip  18  and a fingerprint scanner connector  19 . 
     USB hub chip  14  of PCBA  800  expands the single USB connection of USB connector with computer  40  ( FIG. 21 ), or other USB reading electronic device, into multiple USB connections which connect PCBA  800 ,  400  and  900  of drive  92  together. USB hub chip  14  may also be used in other embodiments to connect further printed circuit board assemblies with one connection between USB connector  50  and computer  40 . In addition USB hub chip  14  could provide connection information to control microprocessor  12  of PCBA  800 , to control microprocessor  12  of PCBA  400  and to control microprocessor  12  of PCBA  900  to make the microprocessors aware of the existence of PCBA  800 ,  400  and  900  of drive  92 , and optionally prioritize the display of data between them. 
       FIG. 15  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD)  90  with an outer housing  21 . It includes non-secured storage printed circuit board assembly depicted in  FIG. 12  together with an outer housing  21  and a fingerprint scanner  60 . All components of  FIG. 12 , namely the printed circuit board assemblies  500 ,  400  and  900  fit within housing  21  and are not visible from the outside of housing  21  when in normal use. Devices  500 ,  400  and  900  are configured, connected and operate as discussed above with respect to  FIG. 12 . Fingerprint scanner  60  is operatively connected to fingerprint scanner connector  19  which is connected in turn to fingerprint chip or microprocessor  18 . 
     As printed circuit board assemblies of devices  400  and  900  both have a code generating chip  13  they can each have a unique code. If they have their own unique code, they could have their own cross checking security function between USB Control Chip  12  and Code Generating Chip  13  of each PCBA  400  and  900 . And also when connected to central database server  30  as in  FIG. 21 , the central database server  30  can consider each PCBA  400  and  900  as independent USB Drives. Central database server  30  could manage devices  400  and  900  with different levels of security. 
       FIG. 16  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD)  80  of the present invention as discussed above with reference to  FIG. 11 , with a non-secured storage printed circuit board assembly  500  of  FIG. 5  as the initial printed circuit board assembly and a secured storage printed circuit board assembly  400  of  FIG. 4  as a higher level PCBA, connected in series with the assembly of  FIG. 4  oriented above the assembly of  FIG. 5 . Shown schematically is the serial flow of data through the MLUD on access by a user. Data enters the Multi-Layer USB Drive (MLUD) through USB connector  50  and is directed to non-secure control chip  11  to access data from, or store data to, flash memory  15  of PCBA  500 . A user can also access secure control microprocessor  12  of PCBA  400  on the input of an access step with access to flash memory  15  of PCBA  400  controlled by security. The security requirements of PCBA  400  are reproduction of a code generated by the code generating chip  13  and the security requirement controlled by the USB control chip  12 , such as a user name and password. 
       FIG. 17  is a schematic view of internal components of the Multi-Layer USB Drive (MLUD)  90  of the present invention as discussed above with reference to  FIG. 12 , with a non-secured storage printed circuit board assembly of PCBA  500  of  FIG. 5  as the initial PCBA, a secured storage printed circuit board assembly of PCBA  400  of  FIG. 4  as a higher level PCBA, and a secured storage printed circuit board assembly of PCBA  900  depicted in  FIG. 9  as yet a higher level PCBA, connected in series with the assembly of  FIG. 9  oriented above and connected to the assembly of  FIG. 4  and the assembly of  FIG. 4  oriented above and connected to the assembly of  FIG. 5 . Shown schematically is the serial flow of data through the MLUD on access by a user, together with an outer housing  21  and a fingerprint scanner  60 . The flow of data through USB connector  50 , PCBA  500  and PCBA  400  are as discussed above with reference to  FIG. 16 . Data may only be stored in and retrieved from flash memory  15  of PCBA  900  by a user who has successfully passed through a security requirement of reproduction of a code generated by the code generating chip  13  of PCBA  900 , and who has successfully passed through a security requirement controlled by the USB control chip  12  of PCBA  900  such as a user name and password, and by matching a fingerprint using fingerprint chip  18  and a fingerprint scanner connector  19 , both of PCBA  900 . Data to flash memory  15  of PCBA  900  flows from USB connector  50 , non-secure controller  11  of PCBA  500 , secure controller  12  of PCBA  400  and secure controller  12  of PCBA  900  to flash memory  15  of PCBA  900 . 
     Referring to  FIG. 16 , when the Multi-Layer USB Drive (MLUD) is connected to a Computer  40 , the Computer  40  recognizes and sees only the printed circuit board assembly of PCBA  500 . And after the user accesses the printed circuit board assembly of PCBA  500 , the user can see an icon of the printed circuit board assembly of PCBA  400 . To access the data on memory  15  of PCBA  500 , it would be not require any security because PCBA  500  is not secured. When the user tries to access the data on memory  15  of PCBA  400 , as it has Security USB Chip  12 , the user will have to pass through security, such as a password. If the password is not correct, then the user cannot access the data on memory  15  of PCBA  400 . 
     Referring to  FIG. 17 , a further level of printed circuit board assembly of PCBA  900  is provided, which has security USB chip  12 , code generating chip  13  and fingerprint chip  18 . To access the data in memory  15  of PCBA  900 , the user must first go through PCBA  500 . PCBA  500  does not require the security for access. While accessing PCBA  500 , a user may be aware of a visible icon or other means of accessing the next level of printed circuit board assembly This could be by clicking an icon on the screen for access to PCBA  400 . When a user accesses the data in memory  15  of PCBA  400 , the user must pass through security controlled by secure USB control chip  12 , such as a user name and password. Upon access to PCBA  400 , the user may be aware of an visible icon or other means of accessing the next level of printed circuit board assembly. This could be by clicking an icon on the screen for access to PCBA  900 . PCBA  900  includes the fingerprint scanning security and will require a user to scan his/her fingerprint for access to printed circuit board assembly of PCBA  900 . If the fingerprint scanner recognises the user&#39;s fingerprint as authorised for access, then the user can the data in memory  15  of PCBA  900 . This process is an implementation of serialised data access. Users must access all lower levels before access can be granted for the next higher level. 
     And as a further example with reference to  FIG. 17-1 , the Multi-Layer USB Drives (MLUD)  90  of printed circuit board assemblies  500 ,  400 ,  400 , and  900  are connected using Pin  17  and Pin  17 - 1 . And PCBA  500  is a non-secured storage Drive with USB hub chip  14 , and the printed circuit board assemblies  400  and  900  have a secured storage each with a code generating chip  13 . As an example, the user could configure the printed circuit board assemblies as follows. The data at the Multi-Layer USB Drive (MLUD) of PCBA  500  could be accessed by anybody when they plug the USB Drive into the Computer  40 .
         The data at the next level Multi-Layer USB Drive (MLUD) of PCBA  400  (first instance) could be accessed by clicking of an icon on the computer screen showing PCBA  500  information, and requiring a password. In addition this Data in the memory  15  of PCBA  500  could be configured, for example, as: “print permitted”, “edit permitted”, “copy prohibited”, “email prohibited”.   The data at the next level of PCBA  400  (second instance) could be accessed by clicking of an icon on the computer screen for prior PCBA  400 , requiring a password. And also the data of that next level drive of PCBA  400  (second occurrence) could be configured, for example as: “print permitted”, “edit permitted”, “copy permitted”, “email prohibited”.   The data at the next level of PCBA  900  could be accessed by clicking of an icon on the computer screen for prior PCBA  400  (second instance), and require another password. And in addition it could require fingerprint verification by fingerprint chip  18 . And also the in memory  15  of PCBA  900  could be configured such that all such data is “Ready Only” and “Copy Prohibited”.   In conclusion to access to the data of PCBA  900  in this configuration, the user is required to go through password protection three times ( 400 → 400 → 900 ) and one fingerprint scan verification for PCBA  900 . And even with access the data in memory  15  of PCBA  900  is “Ready Only” and “Copy Prohibited”.   And further if the generated codes from PCBA  400  (first instance), PCBA  400  (second occurrence) and PCBA  900  are registered to central database server  30 , central database server  30  can report as to who/when/what data was accessed. And central database server  30  could upload requested Data to a designated Multi-Layer USB Drive (MLUD), and also delete data at the Multi-Layer USB Drive (MLUD).       

     With other printed circuit board assembly combinations, the user could configure the complete Multi-Layer USB Drives (MLUD) in other ways. 
       FIG. 18  is a flow chart of the serialized data access flow of Multi-Layer USB Drive (MLUD) of  FIG. 17 . 
       FIG. 19  is schematic view of internal components of the Multi-Layer USB Drive (MLUD), with a non-secured storage printed circuit board assembly of  FIG. 5 , a secured storage printed circuit board assembly of  FIG. 4 , and a secured storage printed circuit board assembly of  FIG. 9 , connected in parallel with USB connector  50 . 
       FIG. 20  is a flow chart of the parallelized data access flow of Multi-Layer USB Drive (MLUD) of  FIG. 19 . 
       FIG. 21  is schematic view of internal components of the Multi-Layer USB Drive (MLUD) of  FIG. 17  for operative connection with a central database server to control the Multi-Layer USB Drive (MLUD) of  FIG. 17  and its function, through wired or remote connection. 
       FIG. 22  is a schematic view of a screen display showing the control parameters of the printed circuit board assemblies of  FIGS. 5 and 9  combined as in a Multi-Layer USB Drive (MLUD) of the present invention. 
       FIG. 23  are two schematic views of alternate exemplary storage systems to which the invention can be applied, an SD card with two flash storage drives and a portable hard drive with two flash storage drives. In each embodiment the drives (in one labelled  1000  and in the other labelled  1100 ) are connected serially with one drive being the initial drive and the other a drive at the next level. Operation is the generally similar as discussed with respect to  FIGS. 11 and 16  herein. 
     Several different types of security options are available for each printed circuit board assembly such as Password, Encryption, Fingerprint Recognition, DRM (Digital Rights Management), Security Tokens, Data Masking, Anti-Virus, etc. 
     Additional printed circuit board assemblies could be added as long as there is sufficient room within housing  21 . 
     As an option one code generating chip  13  could be included in one Multi-Layer USB Drive (MLUD) configured to receive instructions from computer  40  to effect all PCBA′ in the MLUD, by having the code the same for all PCBAs of the MLUD. This one command, for example to “delete all data”, sent from computer  14  would affect all PCBA of the MLUD, for example to delete all data from all PCBAs in the MLUD. Alternatively, if so configured commands from computer  40  could act on a specific PCBA of the MLUD, or some but not all PCBAs, or each one separately. In that case, computer  40  (which may be a central database server) manages the PCBAs in the manner indicated. 
       FIG. 21  depicts of the process diagram of Central Database Server  30  and its function which could be connected remotely with Multi-Layer USB Drive (MLUD)  90  through a computer  40 . The remote connection method could be through Internet (TCP/IP; Transmission Control Protocol/Internet Protocol) or other communication method. On printed circuit board assembly  500  or other printed circuit board assembly  400  and  900  which have Code Generating Chip  13 , it will generate a unique code which could be identified by central database server  30 . This unique code could be normal Serial number or MAC (Media Access Control)/IP address type of code when the Code Generating Chip  13  has the function of Networking. Also this Code Generating Chip  13  will contain the IP address of Central Database Server  30 , and could initialize the connection with Central Database Server  30  through TCP/IP communication when it is available. 
     The Code from the Code Generating Chip  13  could have several functions depend on the design. This Code is to identify the Multi-Layer USB Drive (MLUD). This Code stores at the exact Multi-Layer USB Drive (MLUD) USB Control Chip  12  and the Code Generating Chip  13 . When the user is trying to access the Data in the Flash Memory  15 , the Data Access on the Multi-Layer USB Drive (MLUD) should be asked for the Code to identify the authentication first by USB Control Chip  12 . And it is option to double check on the Code Generating Chip  13 . If the Code entered is different to the Code in USB Control Chip, then the Access should be denied. If the Code entered is correct, then USB Control Chip could ask one more time to check with Code Generating Chip  13 . If there is right feedback from the Code Generating Chip  13 , then user could access the Data. This double checking concept could improve the security of Multi-Layer USB Drive (MLUD). And this Code concept could be used for different functions such as Remote Data Access by Network, Wireless explained on  FIG. 20 , Rule management for the Drive including Copy permit, Print permit, Email permit, Lock, Deletion and so on. This management options could be configured to each Multi-Layer USB Drive (MLUD) independently if they have different Codes. 
     It should be understood that the code generated by code generating chip  13  performs an important function in identifying authorized access and permitted data communication as described with respect to  FIG. 21 . It is also important to store the code on USB Control Chip  12 , not on in the data of flash memory  15  to prevent unauthorized user from accessing the code by bypassing controller  12  to the database level or flash memory. It will also prevent an unauthorized user from physically removing the flash memory  15 , installing it on another USB control chip and accessing the data, as the flash memory could be operated only with a control chip which has the same code. The user can then be verified by USB control chip  12  before the user is permitted to accesses the data. 
     Each of devices  400  and  900  could have their own unique code by means of code generating chip  13  on each of devices  400  and  900 . As such each PCBA  400  and  900  could be set up with its one unique set of access rules. For example PCBA  400  could be configured for print permission, no copying permitted and no e-mailing permitted. And as an example PCBA  900  could be configured for print permission, copying permitted and emailing permitted. Also this could be managed by the central database server  30  as displayed in  FIG. 22  as an example. On the other hand, as alternative option, devices  400  and  900  could have the same code, and then could be managed with the same rules. 
     After the confirmation of the identification between the Multi-Layer USB Drive (MLUD) and central database server  30 , central database server  30  could manage the Multi-Layer USB Drive (MLUD) remotely. The functions of central database server  30  could have functions controlling Upload/Download the data between Multi-Layer USB Drive (MLUD) and Server  30 , remote locking up, deletion and recovery, etc. This could also include secure message communication, to the authorized user of the Multi-Layer USB Drive (MLUD).  FIG. 21  shows the flow of data. 
       FIG. 23  depicts exemplary types of other USB Drives which could implement the subject invention, such as Memory Cards, SD card, micro SD card, mini SD card, MMC card, MMC micro card, MS card, MS Duo card, CF card, PCMCIA card, xD card, etc. A Multi-Layer SD Card could have several SD Card module PCBAs  1000  which could have different security functions. A Multi-HDD (Hard Disk Drive) Mobile USB Drive could have several HDD  1100  which could have different security functions through a Control module  1200  which has Security USB control Chip  12 , Non Security USB control Chip  11 , Code Generating Chip  13 , USB Hub chip  14 , and if desired additional security function chips such as a fingerprint chip. 
     From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the disclosure. The various printed circuit board assemblies as depicted in  FIGS. 1 through 9  can be combined in a multiple ways to form a variety of Multi-Layer USB Drives (MLUD). Aspects of the invention described in the context of particular embodiments may be combined or eliminated in other embodiments. Further, while advantages associated with certain embodiments of the invention have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and no embodiment need necessarily exhibit such advantages to fall within the scope of the invention. Accordingly, the invention is not limited, except as by the appended claims.