Abstract:
The present invention teaches a powerless lockable UFD system and a method for securely protecting information stored and retrieved on UFDs (USB flash drives) that does not require electric power in order to enter a password to the UFD. The system also features an alarm and reset mechanism for clearing entered passwords. Passwords are concealed from the sight of a viewer for further protection. The system can be similarly incorporated into peripheral devices such as hard-disk drives (HDDs), printers, scanners, cameras, and portable memory devices.

Description:
[0001]    This patent application claims the benefit of U.S. Provisional Patent Application No. 60/755,992 filed Jan. 5, 2006. 
     
    
     FIELD AND BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a powerless lockable UFD system and a method for securely protecting information stored and retrieved on UFDs (USB flash drives) that does not require electric power in order to enter a password to the UFD. 
         [0003]    UFDs are well-known in the art of digital computing as devices for portable storage of digital data. As UFDs become more popular, they are increasingly being used for storage of private and confidential information. The likelihood of small UFDs being lost, stolen, or accidentally exchanged is significant. The two factors cited above create a major information security problem, where confidential information can be accessed by unauthorized users. Solutions that improve the security of information on UFDs are well-known in the art, and include encryption, password protection, and biometric identification methods. 
         [0004]    Additional solutions to this security problem have been offered, such as physical locking of the UFD (U.S. patent application Ser. No. 11/318,473). A representative family of solutions to this problem is using a combination lock that is part of the UFD. The UFD is rendered operational only if the right combination is set on the combination lock. This family of solutions has an inherent advantage compared to other types of solutions. They relieve the user from having to deal with security issues after the UFD has been inserted into its host system. Other methods, such as entering a password through the host system or decryption of files on the UFD, require the user to interact with the UFD, through the host system, after it has been inserted into the host system. This is both a burden to the user, and a security hazard as the host system may be programmed to trace and capture the information retrieved from the UFD. 
         [0005]    State-of-the-art systems, that allow a user to independently unlock a UFD apart from a host system, are all electromechanical and require a power source, typically a battery. While this is not a major problem, as the power consumption is small relative to the battery capacity, it is a risk, as the user may not tolerate a depleted battery depriving him from his information. Furthermore, including a battery would also increase product cost and complexity. 
         [0006]    It would be desirable to have a system for locking and unlocking UFDs in which the lock can be unlocked while the UFD is separated from the host system, and without the need for an electric power source. 
       SUMMARY OF THE INVENTION 
       [0007]    For the purpose of clarity, the term “UFD” is specifically defined for use within the context of this application. The term “UFD” is used in this application to refer to a USB Flash Drive or any other portable storage device. While the “U” in “UFD” stands for USB, it does not imply that the connector must be only a USB connector. Similarly, while the “F” in “UFD” stands for “Flash”, it does not limit the storage technology to be flash technology. Finally, the “D” in “UFD” stands for “Drive”, but does not limit the storage device to function like a disk drive. The term UFD is used for convenience, since the storage device will indeed be a UFD in most implementations of this invention. 
         [0008]    The term “powerless” is used in this application to refer to a device lacking a persistent power source. Thus, the present invention includes embodiments where power is extracted from the user&#39;s interaction. The term “verification” is used in this application to refer to the process of determining that a current mechanical state of the password-entry mechanism is identical to a predetermined mechanical state of the password-entry mechanism by the state-identifying mechanism. The term “relatively long” is used in this application to refer to a span of time longer than the longest time it would be expected to be necessary for a user to physically make the insertion operation of a UFD into a host system. 
         [0009]    It is the purpose of the present invention to teach a system for protecting a UFD with a password, where the password is interpreted when the UFD is powered by the host system, but is entered by the user prior to the insertion of the UFD to the host system. While the standard definition of a password would include any unique alphanumeric sequence, used as a verified identifier for device access and use, using mechanical buttons in this case, the term “password” is used in this application to primarily include the correct setting of dials, sliders, switches, and/or other mechanical devices. 
         [0010]    Moreover, in a preferred embodiment of the present invention, the password is interpreted inside the UFD and is not communicated to the host system, so that it is difficult or impossible to capture the password using the host system. 
         [0011]    In a preferred embodiment of the present invention, the password can be altered by the user using a trusted host system. 
         [0012]    In another preferred embodiment of the present invention, the password can be introduced through the host system in case the user is not able to enter the password via the mechanism on the UFD due to a mechanical problem. 
         [0013]    In another preferred embodiment of the present invention, the password is embedded in a token that can be attached to the UFD, and does not require entering a password. 
         [0014]    In another preferred embodiment of the present invention, the UFD is unlocked in response to a successful challenge-response dialogue with the token. 
         [0015]    Combinations of the above-mentioned embodiments are also considered embodiments of the present invention. 
         [0016]    Therefore, according to the present invention, there is provided for the first time a powerless lockable UFD system, the system including: (a) a password-entry mechanism having a plurality of distinguishable mechanical states configured to be operationally connected to a UFD; (b) a state-identifying mechanism for identifying the plurality of distinguishable mechanical states; and (c) an electrical mechanism for effecting operational connectivity between the UFD and a host system only upon: (i) external powering of the state-identifying mechanism; and (ii) verification that a current mechanical state of the password-entry mechanism is identical to a predetermined mechanical state of the password-entry mechanism by the state-identifying mechanism. 
         [0017]    Preferably, the password-entry mechanism includes at least one mechanical knob. 
         [0018]    Preferably, the password-entry mechanism includes at least one mechanical button. 
         [0019]    Preferably, the state-identifying mechanism is located on the host system. 
         [0020]    Preferably, the predetermined mechanical state is configured to automatically change, after a single session of use of the UFD, according to a predetermined sequence. 
         [0021]    Preferably, the predetermined mechanical state is concealed from the view of an observer upon being entered into the password-entry mechanism. 
         [0022]    Preferably, the system further includes: (d) a state-changing mechanism for changing the predetermined mechanical state. 
         [0023]    Preferably, the predetermined mechanical state is a predetermined angular position of at least one wheel. 
         [0024]    Most preferably, a rotation of at least one wheel is configured to change an electrical resistance between two wires. 
         [0025]    Preferably, at least one wheel is configured such that rotation of at least one wheel changes an encoding of a shaft encoder. 
         [0026]    Preferably, the state-identifying mechanism is located on the UFD. 
         [0027]    More preferably, the UFD is configured to be powered by the host system. 
         [0028]    Most preferably, the state-identifying mechanism is configured to start operating automatically upon powering of the UFD. 
         [0029]    Preferably, the system further includes: (d) a resetting mechanism for resetting the electrical mechanism upon a relatively long disconnection of the UFD from the host system, thereby requiring re-establishment of said predetermined mechanical state in order to re-effect said operational connectivity between the UFD and the host system. 
         [0030]    Preferably, the system further includes: (d) an alarm mechanism for reminding a user to change the current mechanical state of the password-entry mechanism upon the operational connectivity between the UFD and the host system being established. 
         [0031]    Most preferably, the alarm mechanism is configured to periodically alert the user to modify the current mechanical state while the UFD is connected to the host system. 
         [0032]    Most preferably, the alarm mechanism is configured to deny operational connectivity between the UFD and the host system until the current mechanical state is changed. 
         [0033]    According to the present invention, there is provided for the first time a powerless lockable peripheral-device system, the system including: (a) a password-entry mechanism having a plurality of distinguishable mechanical states configured to be operationally connected to a peripheral device; (b) a state-identifying mechanism for identifying the plurality of distinguishable mechanical states; and (c) an electrical mechanism for effecting operational connectivity between the peripheral device and a host system only upon: (i) external powering of the state-identifying mechanism; and (ii) verification that a current mechanical state of the password-entry mechanism is identical to a predetermined mechanical state of the password-entry mechanism by the state-identifying mechanism. 
         [0034]    Preferably, the peripheral device is selected from the group consisting of: a hard-disk drive (HDD), a printer, a scanner, a camera, and a portable memory device. 
         [0035]    According to the present invention, there is provided for the first time a method of accessing data stored on a powerless lockable UFD, the method including the steps of: (a) configuring the UFD to compare a mechanical state of at least one password-entry mechanism to a predetermined mechanical state upon external powering of the UFD; (b) setting the mechanical state to a first state; (c) operationally connecting the UFD to a host system subsequent to the step of setting the mechanical state to the first state; (d) comparing the first state to the predetermined state upon powering of the UFD by the host system; and (e) enabling an operational connectivity between the UFD and the host system only upon a match between the first state and the predetermined state. 
         [0036]    These and further embodiments will be apparent from the detailed description and examples that follow. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]    The invention is herein described, by way of example only, with reference to the accompanying drawing, wherein: 
           [0038]    The sole FIGURE shows a simplified block diagram of a system according to some embodiments of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0039]    The present invention relates to a powerless lockable UFD system and a method for securely protecting information stored and retrieved on UFDs (USB flash drives) that does not require electric power in order to enter a password to the UFD. The principles and operation of a powerless lockable UFD system, according to the present invention, may be better understood with reference to the drawing and the accompanying description. 
         [0040]    Referring now to the drawing, the FIGURE shows a simplified block diagram of a system according to some embodiments of the present invention. A UFD  22 , such as a DiskOnKey™ portable memory available from M-Systems Inc. of Kefar Saba, Israel, is connected to a host system  24  such as a personal computer. UFD  22  has a storage area  36  used for storage of data that is transferred between storage area  36  and host system  24  via a controller  34  in UFD  22 . Controller  34  is designed to deny access to storage area  36  to host system  24  unless there is an indication from a password comparator  30  that such transaction is permitted. 
         [0041]    Password comparator  30  gives permission to controller  34  if password comparator  30  is satisfied that a password received from a password decoder  28  is compatible with a nominal password stored in a password storage  32  within UFD  22 . Password comparator  30 , password storage  32 , and controller  34  are physically located in proximity to each other on a single electronic chip  23 . This prevents a hacker from being able to access a password confirmation  33  between comparator  30  and controller  34 . Such access would enable a hacker to provide controller  34  with a false indication that the password is correct. 
         [0042]    One or more mechanical position indicators  26  are located in a password entry  20  that can be an integral part of UFD  22 , or can be a separate part that attaches to UFD  22 . Position indicators  26  can be potentiometers, a ladder of resistors, an array of miniature switches, an array of thumbwheel switches, an optical shaft encoder, or any other mechanism by which a stable mechanical setting can be recognized by an electrical mechanism. 
         [0043]    When the user plugs UFD  22  into host system  24 , UFD  22  is powered by host system  24  through its connector, typically a USB connector. Upon activation, password decoder  28  converts the outputs of position indicators  26  into a digital password. In a preferred embodiment of the present invention, the outputs of position indicators  26  take the form of an analog component value, such as resistance or capacitance, and password decoder  28  converts the analog values into a digital number. In another preferred embodiment of the invention, password decoder  28  triggers active devices in position indicators  26 , such as one or more light sources and photoelectric cells, and reads the digital output. 
         [0044]    Once password decoder  28  has converted the outputs of position indicators  26  into a digital value, password decoder  28  outputs this digital value (i.e. the password) to password comparator  30 . Password comparator  30  compares this password with the nominal password stored in password storage  32 . If there is a match between the two passwords, password comparator  30  sends an indication, via password confirmation  33 , to controller  34  to enable access to storage area  36 . 
         [0045]    The user can change the password when UFD  22  is unlocked. In one preferred embodiment of the present invention, this procedure is accomplished by a setup software application  38  on host system  24 . Host system  24  is protected by conventional methods of security access control regulated by an operating system  40 , such as a password, biometrics, or a token. It is noted that, in another preferred embodiment of the present invention, password decoder  28  and password comparator  30  are located on host system  24 . 
         [0046]    In another preferred embodiment of the present invention, the password of UFD  22  can be reset by activating a momentary button  42  on UFD  22  as follows. Depressing momentary button  42 , while UFD  22  is unlocked, will activate the current settings of position indicators  26  to be a new password. This enables the user to change the password without requiring access to a trusted host system. Preferably, the required depression of momentary button  42  for activation should be long and intermittent in order to avoid an accidental activation, which may change the password to incidental settings of position indicators  26 . 
         [0047]    Since UFD  22  is inserted into host system  24  with position indicators  26  set to the secret password, there is a risk that a person that has access to UFD  22 , when operational, will see the settings of position indicators  26 , thereby obtaining the password. This is an undesirable situation which can be avoided by concealing the password in numerous ways. According to preferred embodiments of the present invention, the password can be concealed in the following ways, among others:
       (1) A motor (not shown) embedded in UFD  22  can shuffle position indicators  26  once UFD  22  has been unlocked.   (2) The system can keep UFD  22  unlocked for a short period, typically five seconds, after it has been unlocked. This requires keeping the electronics of UFD  22  operational for five seconds, so that it does not reset to the locked position when detached from host system  24 . The small amount of electricity necessary to maintain this period can be provided by a charged capacitor (not shown). According to this embodiment, the user sets position indicators  26  to the correct password, plugs UFD  22  into host system  24 , verifies that UFD  22  has been unlocked, briefly pulls UFD  22  out of host system  24  to shuffle position indicators  26 , and then plugs UFD  22  back into host system  24  for use.   (3) A sentinel software application (not shown) can monitor password confirmation  33 , and periodically alert the user to shuffle position indicators  26 , while UFD  22  is in use, until the software application verifies that the outputs of position indicators  26  have been changed (through password confirmation  33 ). Alternatively, the sentinel software application can disable the use of UFD  22  until position indicators  26  have been shuffled.   (4) The nominal password can be automatically changed by setup software application  38  during each activation session, according to a predetermined sequence, so that the user has to use a different password upon each entry. In this embodiment, viewing UFD  22  in operation does not provide useful information to a hacker.   (5) Password entry  20  and position indicators  26  can be configured such that, upon completion of password entry, the password is concealed from the view of an observer by keeping the password setting in a hidden location within UFD  22 . An example such a configuration is the mechanism used in common rotating tumbler locks. In these types of locks, the user rotates the dial to set each tumbler in sequence, but the position of the tumblers can&#39;t be seen from outside the lock.   (6) A set of buttons can be used as position indicators  26 , and can be configured such that, upon completion of password entry, the password is concealed from the view of an observer by keeping the depressed sequence in a hidden location within UFD  22 . The depressed buttons would not be visibly different from buttons that were not depressed. A separate button can be configured for clearing the state of all the buttons.       
 
         [0054]    It is noted that among the embodiments included in the present invention, the powerless electronic lock described above can be utilized in devices other than UFDs. A locking device, according to the present invention, can be similarly incorporated into an array of detachable peripheral devices that connect to host systems. Thus, similar security and convenience features can be provided to devices such as: an external hard-disk drive (HDD), a printer, a scanner, a camera, a portable memory device, and other types of peripheral devices. 
         [0055]    While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications, and other applications of the invention may be made.