Abstract:
A portable electronic system configured for a secure transaction includes a card having a width, length, and thickness, wherein a ratio of length to thickness is at least 5. The card includes a storage medium to store data and an integrated circuit device (“IC”) including security information. The security information stored in the IC is used to authenticate an access request to the storage medium.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]    The present application claims priority to U.S. Provisional Patent Application No. 60/427,412, filed on Nov. 18, 2002, which is incorporated by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to a secure transaction card having a storage area.  
           [0003]    Generally, users would like transactions, which could be an activity such as a financial exchange or the execution of a procedure to verify the identify of an individual or establishing a communication link between parties, to occur in a trusted environment and in the least amount of time. Currently, a number of platforms have been developed that provide a means to interact with other parties. In one configuration the communication occurs over a fixed network. The preferred requirement is for availability at anytime and anywhere but the unpredictability of network traffic limits the usability of such a system. Additionally, there are security concerns since confidential data may be transmitted over a public network; also civil liberty issues since personal information is communicated to a system which may be under the control of third parties.  
           [0004]    Other methods utilize a card with electronics mounted on it. Such a card is referred to as a Smart Card. The Card carries the owner&#39;s credentials and provides a low level of authentication to complete a transaction. Smart Cards have about 16 kilobytes of data storage, which limits the level of security afforded by these cards. Smart Cards have the form factor of a credit card.  
           [0005]    The Smart Cards integrated circuit is further constrained by the very small thickness of the Card and the requirement for a flexible structure. The electrical connection is via surface contacts with large pad areas creating a higher capacitance that limits the data transfer rate available from such a device. Despite these concerns, the Card is easily transportable and is very convenient to use.  
         BRIEF SUMMARY OF THE INVENTION  
         [0006]    In one embodiment, a portable electronic system configured for a secure transaction includes a card having a width, length, and thickness, wherein a ratio of length to thickness is at least 5. The card includes a storage medium to store data and an integrated circuit device (“IC”) including security information. The security information stored in the IC is used to authenticate an access request to the storage medium.  
           [0007]    The portable electronic system also includes a reader to access the storage medium. The reader includes a first interface and a second interface. The first interface is configured to interface with the IC. The second interface is configured to interface with the storage medium. The ratio of the length to thickness of the card that is at least 8. Alternatively, the ratio of the length to thickness of the card is at least about 10. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 illustrates a secured transaction card according to one embodiment of the present invention.  
         [0009]    [0009]FIG. 2 shows a card reader conforming to the PC Card form factor according to one embodiment of the present invention.  
         [0010]    [0010]FIG. 3 shows a card with an integrated circuit and a rotating disk storage volume according to one embodiment of the present invention.  
         [0011]    [0011]FIG. 4 illustrates certain internal details of the card of FIG. 3.  
         [0012]    [0012]FIG. 5 shows certain internal details of a PC Card reader that works with the card shown in FIGS. 3 and 4.  
         [0013]    [0013]FIG. 6 illustrates a block diagram of components in a secured transaction card according to one embodiment of the present invention.  
         [0014]    [0014]FIG. 7 illustrates a block diagram of an integrated circuit mounted on the card shown in FIGS. 3 and 4 according to one embodiment of the present invention.  
         [0015]    [0015]FIG. 8 shows an architecture of the electronics in the security module associated with a secured transaction card according to one embodiment of the present invention.  
         [0016]    [0016]FIG. 9 shows a secured transaction card with Flash memory according to one embodiment of the present invention.  
         [0017]    [0017]FIG. 10 is a side view of the card of FIG. 9.  
         [0018]    [0018]FIG. 11 is a top view of the integrated circuit contact pads of the card of FIG. 9.  
         [0019]    [0019]FIG. 12 depicts a structure of electronic components utilized in this Card.  
         [0020]    [0020]FIG. 13 shows the electrical contacts for the Card with Flash memory.  
         [0021]    [0021]FIG. 14 illustrates a block diagram of the architecture of the integrated circuit on the Card with Flash memory and the reader required to operate with this Card. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    [0022]FIG. 1 illustrates a secured transaction card  1  as shown in FIG. 1. The card is configured similar to a Smart Card with an integrated circuit and surface contacts  2  and conforms to ISO 7816-1 and -2 specifications. Card  1  is inserted into a reader  3 , such as that shown in FIG. 2. Card  1  is inserted into reader  3  through a slot  4  on one side of the reader, and it communicates with a host system through connector  5  on the opposite side.  
         [0023]    In one embodiment, the card has a credit card form factor and conforms to the ISO 7816 specification. The ISO 7816 specification requires the card to have approximate dimensions of 3.37 inch by 2.125 inch by 0.03 inch. In other embodiments, the card may not have a credit card form factor. The dimensions of card may vary according to applications. The card may have a thickness anywhere in the range from 0.25 inch to 0.020 inch according to one embodiment of the present invention. In another embodiment, the card can be configured with a thickness in the range from about 0.020 inch to about 0.04 inch to allow the card to fit the sleeves in personal wallets. The card may also be provided with a length in the range from 0.5 inch to 4 inches. The width of the card may be in the range from 0.5 inch to 3.0 inches.  
         [0024]    [0024]FIG. 3 shows one embodiment of card  1 , which is constructed as a laminated structure. The card includes an integrated circuit with surface contacts  6  according to the ISO standard. Card  1  is thin and includes a flexible magnetic disk  7  housed in a cavity formed between the top cover  9 , a core layer and the bottom cover  11  (FIG. 4). The disk thickness is about 0.0025 inch and the top cover  9  is about 0.006 inch, and the bottom cover  11  is made from a sheet of stainless steel about 0.003 inch thick. The core layer is about 0.018 inch thick. These layers are glued together forming card  1  with a thickness of about 0.030 inch. The cavity that contains disk  7  is about 0.015 inch in thickness. The surfaces of this cavity that face the disk are covered with a fabric liner (not shown). This liner protects disk  7  from contacting layers  9  and  11  of card  1 .  
         [0025]    [0025]FIG. 4 shows the bottom of card  1 . There is an opening  12  in the bottom layer  11  behind which is located a shutter mechanism  13 . This mechanism operates in a cavity formed in the core layer. The purpose of shutter  13  is to allow the recording surface of disk  7  to be exposed so that recording head  21  located in reader  3  can read and write information to the disk. Shutter  13  is made from 0.003 inch thick stainless steel sheet and reinforced by a 0.010 inch plastic member  17  attached at one end.  
         [0026]    A pin, located in reader  3  (not shown), actuates the shutter through opening  15 . The pin is located in slot  17  and upon continued insertion of card  1  into the reader the shutter is moved to position opening  20  in the shutter with opening  12  in plate  11 . The pin in the reader moves in slot  19  fabricated in the bottom plate  11 . Disk  7  is glued to a metal hub  16  and engages with spindle motor flange  22  mounted in reader  3 , whereby the disk can be rotated at high speed to read and write data on disk  7 . Upon removal of card  1  from reader  3 , the pin moves shutter  13  to close the opening  12 . The shutter gets locked in this position to eliminate casual actuation and protect contaminants from entering the disk enclosure.  
         [0027]    [0027]FIG. 5 illustrates a reader  3  according to one embodiment of the present invention. Reader  3  is constructed as a Type II PC Card being 0.197 inch thick. It can be inserted into slots available in portable computers, where communication can be established between the host system and reader  3  through a connector  5 . Spindle motor  22  in the reader centers the disk  7  and hub  16  assembly such that the center of the data track is within a prescribed tolerance of the rotational center of the spindle. Recording head  21  is loaded against disk  7  during operation with a vertical force of about 3 grams. Upon high-speed rotation of disk  7 , head  21  establishes a non-contact interface, whereby information can be recorded to and read from the tracks on disk  7  at high data transfer rates. In one implementation, the data transfer rate is greater than 5 megabytes per second.  
         [0028]    In addition, head  21  can be moved rapidly from track to track on the disk by a Voice-Coil Motor arrangement  25 . The average accessing performance of such a mechanism is less than 0.015 milli-second. Reader  3  contains a printed circuit board  24 , on which are mounted integrated circuits  23  to control the reader mechanism and supervise the flow of data between disk  7 , the integrated circuit  6  and the host system.  
         [0029]    [0029]FIG. 6 shows a block diagram of the electronic architecture of a reader and a card according to one embodiment of the present invention. The components included in the reader is provided inside a line  23 A, and  24 A. The remaining components are included in the card.  
         [0030]    The card integrated circuit (IC)  6  is connected via a secure bus  36  to a security module  33 . This module has a ROM and RAM, a cryptography co-processor in one embodiment running a 3DES or AES encryption algorithm. Module  33  also have a Random number generator. Bus  36  and module  33  are potted with secure epoxy. Data contained on disk  7  is communicated through a separate path and is read by head  21  located in reader  3 . The head generates a signal each time it passes a magnetic transition. These signals are amplified by circuits contained in pre-amplifier  26  and transmitted to the read/write channel  28 . The data is separated and an NRZ serial stream is sent to the disk controller  29 . The controller  29  contains ECC logic to correct data errors and a sequencer to separate the data into blocks and write it to an internal RAM. The disk controller also controls the spindle motor speed and the position of head  21 . The servo loop algorithms operating in controller  29  are interrupt driven, and control the position of the head accurately to follow the centerline of each data track, and to seek the head to other tracks on disk  7 . The data recorded on disk  7  is encrypted and memory  45  (FIG. 7) on the card contains the encryption keys.  
         [0031]    [0031]FIG. 7 illustrates internal functions performed by the card IC  6  according to one embodiment. This is a secure memory device and contains no microprocessor in the present implementation. It can communicate over a serial bus  39  with the Input/Output logic, which in one embodiment conforms to ISO 7816-3 and can operate at a maximum speed of 115 kilo-baud. Power management block  37  and reset logic  42  control the power and security features to keep the memory on the device protected from unauthorized attacks.  
         [0032]    A hardware crypto-function  43  operates in concert with the memory management block  44 . These elements authenticate requests prior to providing access to the session keys stored in memory  45 . Card serial number and enrollment keys are stored in a secure memory area  46 . Memory  45  is partitioned into secure and un-secure zones  45 A and  45 B to allow card  1  to operate as a Smart memory card or as a secure high capacity storage device.  
         [0033]    [0033]FIG. 8 illustrates an internal architecture of module  33  according to one embodiment of the present invention. The microprocessor unit  48  could be a 16 bit or 32 bit RISC processor with an operating system contained in ROM  47 . RAM  50  is accessed on bus  49  which could be an 8 bit or 16 bit bus. Microprocessor instructions can be executed from RAM or ROM. Programs stored in disk  7  can be loaded into RAM  50  and executed. A high-speed cryptography processor  51  with a throughput of greater than 5 megabytes per second, an interrupt controller  52 , and a FIPS  140  compliant Random number generator are also accessible on bus  49 . The module also includes timers  57 , security logic  56 , and an ISO 7816 interface  55  to communicate with card IC  6 .  
         [0034]    Referring back to FIGS. 6 and 7, interface  36  coupling module  33  and card IC  6  includes three interfaces  38 ,  39  and  41 . These three interfaces are potted in reader  3  to keep module  33  secure and tamper-proof. Furthermore, disk controller  29 , read/write channel  28 , pre-amp  26  and spindle motor/VCM driver  27  are circuits that are commonly used in most hard disk drive products. The program code to operate the servo system and the data sequencer is stored in ROM  31 . Data is communicated to the host through interface  30  which could either be PC Card or USB. The disk controller can access RAM  32 . Also microprocessor  48  can read and write to this RAM. In one embodiment data exchange between Controller  29  and secure module  33  is through RAM  32 .  
         [0035]    Disk controller  29  can be emulated and all information in internal RAM and RAM  32  is accessible through interface  30  or through other ports on controller  29 . Microprocessor  48  communicates with the disk controller  29  via interrupts and RAM  32 . Accordingly, all elements in module  33  are secure and immune from attacks. The physical device is potted with secure epoxy along with the connections represented by interface  36  such that any attempts to probe these circuits would require removal of the epoxy and destruction of the device and the respective cables.  
         [0036]    Data written to disk  7  can be encrypted with the session keys stored in memory  45  contained on card IC  6 . As a disk drive the control electronics contains cipher text in the disk controller  29 , internal RAM and external RAM  32 . The encryption keys are communicated between module  33  and the card IC  6  over the secure bus  36 . This architecture can be configured to operate in a variety of ways. As an authentication mechanism, card  1  includes encrypted biometric information of the owner with the encryption keys securely loaded in memory  45 . This is done during enrollment of the user. The card is also provided with a serial number.  
         [0037]    In one embodiment, the procedure of installing the security wall in card  1  includes the serial number and a random number being encrypted together using a two key asymmetric algorithm. A private key would encrypt this information creating a cipher text. This text is stored in block  46 .  
         [0038]    When the card is inserted into a reader  3 , microprocessor  48  would issue a challenge to the card. The card would respond by transmitting this cipher text. Microprocessor  48  decrypts the text using the public key stored in ROM  47  and creates a cipher-gram using a random number from module  53  and a symmetric encryption algorithm similar to that implemented in hardware block  43 . This cipher-gram is sent to card  1 , where it is processed by module  43 . If the results match, the card authenticates the reader. Furthermore, since microprocessor decrypted the initial cipher text successfully the reader is also authenticated.  
         [0039]    At this point microprocessor  48  has access to memory  45  containing the encryption keys and information about disk  7 . Communication over bus  36  is limited to 115 kilo-baud. The challenge response may be executed continuously at this slow speed to ensure continued authenticity of this engagement. Other algorithms may be utilized to achieve the required level of authentication.  
         [0040]    The host has installed in it a biometric sensor or a pin number entry system by which the card owner would request authentication. In one embodiment, the biometric data is transmitted to reader  3  with a request to verify authenticity. This data may reside in internal RAM of the controller or get written to a scratch file on disk  7 . The disk controller transfers control to microprocessor  48 .  
         [0041]    A request for the file containing the encrypted biometric template is issued by microprocessor  48  to controller  29 . The cipher text is fetched from the disk and written to RAM  32  or transmitted serially to module  33 . This information is decrypted and compared with the data written in the scratch disk. A match or a reject result is then communicated from microprocessor  48  to the host via controller  29  and interface  30 .  
         [0042]    Other sequence of events may also be utilized to create a trusted environment where the card and reader authenticate themselves, cipher text is all that can be viewed in the non-secure modules while the decrypted information and file matching is done in the secure module  33 . Many session keys and random numbers may be utilized to achieve the required security.  
         [0043]    This architecture of the card provides a low cost secure memory circuit and a flexible magnetic disk that cost less than $2.00. The reader has the secure micro-controller  33  and logic, which is amortized over a large number of cards to create a secure, low cost access control system. Data rates from the disk may be 5 to 50 megabytes per second in one implementation, while the reader being a larger structure can have circuits in module  33  running at speeds of about 100 to 400 Megabits per second. This provides rapid transactional speed and reduces wait, e.g., reduces the waiting lines at airport security check points, border entry points and secure access to facilities, buildings and transportation systems.  
         [0044]    In another embodiment, disk  7  stores fully encrypted applications with data also encrypted and stored in another file on the same disk. The host requests information, which requires the application and data to be downloaded to module  33  decrypted, executed and the results communicated to the host. This architecture ensures that secure information remains in the card and the reader and only the results are transmitted to the host, whereby a firewall is created between the host and the data on the disk  7 . The encryption keys are stored behind another firewall created in the card integrated circuit during enrollment of the user.  
         [0045]    [0045]FIG. 9 illustrates a card  1 A according to another embodiment of the present invention. Card  1 A is a laminated structure with an integrated circuit module  58  that has multiple devices. Card  1 A conforms to ISO 7816 for flexibility and has the same thickness as a credit card as shown in FIG. 10 in the present embodiment. The card includes a flexible circuit  62 , a plastic housing  59 . FIG. 10 illustrates an enlarged view of the circuit module.  
         [0046]    [0046]FIG. 12 illustrates a cross-sectional view of the card according to one embodiment of the present invention. Surface contacts of module  58  are attached to a circuit block or IC die  61 . In one embodiment, the circuit block is formed on a single semiconductor die and includes the functional blocks illustrated in FIG. 7. A flexible circuit  62  is provided below the IC die  61 . A flash memory  63  is provided below the flexible circuit, i.e., the die and the flash memory are provided on the opposite surfaces of the flexible circuit. The flash memory is used as a storage device in the present embodiment and corresponds to disk  7  in FIG. 6.  
         [0047]    The flash memory die has the dimensions such that it is contained in the area identified for the circuit elements on the card. In the present embodiment, IC die  61  is provided directly over the flash memory. In another embodiment, the circuit module or IC die  61  and flash memory  63  are integrated in a single semiconductor device. In yet another embodiment, the circuit module  61  is spaced apart from the flash memory.  
         [0048]    In the present embodiment, the thickness of the IC die  61  is about 160 microns and the flash memory die is about 210 microns thick. The flexible circuit cable is about 0.002 inch thick. Contact pads are about 0.005 inch thick. The resulting structure has a thickness of about 0.024 inch. This structure is mounted into card  1 A such that it is about 0.006 inch thick to keep the card compliant with ISO specifications.  
         [0049]    The benefit of such a construction is that the electronics are in the same position as in a Smart Card to achieve similar handling characteristics, and the cost of circuit module  61  is not burdened with expensive processing required to fabricate embedded flash memory. Furthermore, this configuration allows two high volume devices to be integrated into a card to provide low manufacturing cost.  
         [0050]    [0050]FIG. 13 shows a bottom view of card  1 A according to one embodiment of the present invention. A plurality of contact pads  65  are provided on the back side of the card. A magnetic stripe  64  is also constructed on the back of the card to provide compatibility with legacy systems. Card  1 A requires a reader with a connector to access contacts  65  and the low speed surface contacts  58 .  
         [0051]    [0051]FIG. 14 illustrates an electronics architecture of card  1 A according to one embodiment of the present invention. The card has a card IC  61  and a flash memory  63 . A reader  3  is used to access the card. The reader has a flash controller  66 , a security module  33 , a data sequencer  68 , and an interface  69 .  
         [0052]    In the present embodiment, the flash memory and the card IC are accessed by the reader using separate communication paths  70  and  72 . The flash memory is accessed using contacts  65 , i.e., communication path  70 . Flash controller  66  provided in the reader manages the read and write operations to the flash memory. The security module  33  is similar to the one described for the rotating magnetic disk embodiment in FIG. 6. The IC  61  is accessed using surface contacts  58  on the front side of the card, i.e., communication path  72  that is coupled to security module  33 . One benefit of using flash memory is that it requires less footprint than the magnetic disk and is price competitive with the magnetic disk for those devices requiring low storage capacities. If the device requires a large storage capacity, the magnetic disk generally is a more economical solution.  
         [0053]    The present invention has been described in terms of specific embodiments. Modifications, alterations, or changes may be made to the illustrated embodiments without departing from the scope of the present invention. Accordingly, the scope of the present invention should be interpreted using the appended claims.