Abstract:
The present disclosure is generally directed toward access control systems and, more specifically, toward access control systems that utilize Near Field Communications (NFC)-enabled devices. The disclosed system enables an NFC device to be remotely checked-in to the access control system; however, the NFC device operates in a read/write mode rather than a card emulation mode when interacting with RFID readers of the access control system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of U.S. Provisional Patent Application No. 61/730,416, filed on Nov. 27, 2012, the entire contents of which are hereby incorporated herein by reference. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    The present disclosure is generally directed toward the use of near field communication (NFC)-enabled devices, such as mobile phones, in access control environments using radio frequency identification (RFID) communication. 
       BACKGROUND 
       [0003]    RFID is currently the dominating technology in physical access control systems. Typical to such systems are “card” readers normally mounted in proximity to a physical point of access (e.g., on a wall next a door or gate or on the doors or gates themselves). The readers read a RFID tag embedded in a card, key fob, sticker or similar form factor. The most popular RFID tags utilize a read/write memory, and many card readers can also read from and write to the tag memory. 
         [0004]    Four standards currently dominate RFID communication: ISO/IEC 14443-A, ISO/IEC 14443-B, ISO/IEC 15693, ISO/IEC 18902, and JIS X6319-4, each of which are hereby incorporated herein by reference in their entirety. Most access control systems installed over the last decade support one or more of these standards, or can be upgraded to support one or more of these standards. Consequently, there is a huge legacy of installed access control readers that use these standards on global basis. 
         [0005]    The same RFID standards are used for other applications such as transport, luggage identification, ticketing, payment according to the Contactless EMV standard (Europay, MasterCard, Visa), and more. 
         [0006]    Due to the wide spread implementation of these RFID standards, the NFC technology that is developed for use in mobile devices, such as smart phones and tablet devices, builds upon the same RFID standards. One could say that NFC is RFID embedded in a phone, instead of a RFID embedded in to a card, key fob, sticker or even a card reader embedded in a phone. 
         [0007]    The NFC hardware can either be an integral part of the mobile device or phone or it can be removable (e.g., a removable NFC chip or device). NFC devices can typically operate in any one of three modes, where the first two modes are most commonly used: (1) card emulation mode; (2) read/write mode; and (3) peer-to-peer mode. 
         [0008]    In the card emulation mode, an NFC device emulates a contactless card in accordance with the above-identified ISO standards, each of which are hereby incorporated herein by reference in their entirety. Typical applications of the card emulation mode include access control applications, as well as payment and ticketing. 
         [0009]    In the read/write mode, the NFC device a tag and typically perform some function based on the information obtained from the read tag. Typical applications of the read/write mode include reading posters with an NFC tag in proximity thereto, interactive advertising, launching mobile Internet (e.g., automated web-browser activation), automated Short Message Service (SMS), and automated call initiation. 
         [0010]    In the peer-to-peer mode, two NFC device, or similar types of devices, are allowed to exchange data with one another. Typical applications of the peer-to-peer mode include setting up wireless settings (e.g., Bluetooth, Wi-Fi, etc.), sharing business cards, or sharing information between the two devices. 
         [0011]    The intention of card emulation is to be able to use the NFC device as a card in the mentioned applications (e.g. access control and payment). 
         [0012]    The NFC card emulation mode is controlled by the Mobile Network Operators (MNOs) via what is called a secure element in the Subscriber Identity Module (SIM) card or some other known device (embedded or removable). The user may need to have a new SIM card prepared for NFC from the MNO if their phone is not natively equipped with a secure element. 
         [0013]    In addition to the SIM card, the NFC card emulation should be enabled on the phone&#39;s operating system. It is not clear if all MNOs include this option and how users will gain access to the option, and it may be that users have to subscribe to and/or purchase this option. Consequently, NFC card emulation for access control will depend on: (1) the timing of MNOs roll out of NFC card emulation in the mobile networks and (2) the cost to subscribe to the service and what the users are willing to pay. 
         [0014]    To be able to use NFC phones for access control independently of the MNOs&#39; control over the card emulation mode, there is a need for a different way to achieve NFC card emulation, including developing a way that can work on the installed base of legacy card readers. 
       SUMMARY 
       [0015]    The NFC modes that are not under control of the MNOs, are: (1) The NFC read/write mode and (2) the NFC peer-to-peer mode. In the NFC read/write mode, the NFC device reads data from or writes data to RFID tags. This functionality is available on all NFC phones currently released; it is directly compatible with four main standards identified above; and, it is not considered a mode that will generate revenue, and is thereby considered “harmless” to MNOs. 
         [0016]    The NFC peer-to-peer mode is a point-to-point communication between two NFC devices to exchange data and a new mode introduced with NFC. It is available to use, but since it competes with Bluetooth (where Bluetooth is faster and handles more devices at a reasonable low energy consumption), there are very few phones that support this mode of operation. 
         [0017]    To bypass the MNOs&#39; control or influence over the NFC card emulation mode, the solution described herein is to use NFC read/write mode, as it is the only NFC mode enabled on current NFC phone and the usage of it is not restricted or controlled by most MNOs. 
         [0018]    One aspect of the present disclosure utilizes an RFID tag, the same or similar to those embedded into cards, and that current card readers can read. The RFID tag is permanently placed in the proximity of a lock&#39;s RFID reader, which is equipped with read/write capabilities. In this manner, the NFC device (e.g., mobile phone or smart phone) can write data to the RFID tag, while the RFID reader of the lock can read the data from the RFID tag. All three devices may exchange information with one another utilizing the NFC read/write mode, for example. 
         [0019]    In accordance with at least one embodiment, the following scenario can be supported by operating an access control system as described above. The guest has a room reservation and prior to arrival the guest receives the option to check-in remotely. Remote check-in can be performed with any type of device, such as a NFC-enabled smart phone or the like. When the guest checks in remotely from an NFC device, the access control system creates a digital key with required access rights. The digital key is sent to the guest&#39;s NFC device where it is stored in memory (e.g., in memory of the NFC device, in a secure element of the NFC device, etc.). Upon arriving to the hotel, the guest presents the NFC device to the lock or more specifically the RFID reader associated with the lock. The NFC device uses NFC read/write to write information to the RFID tag located proximate to the lock, for example, embedded, hidden in or placed behind the front cover of the RFID reader. As an example, the RFID tag is within an acceptable NFC transmission range of the lock (e.g., within approximately 2 feet or less and preferably within 6 inches or less). The information read and/or written may be in the form of one or more NFC Data Exchange Format (NDEF) records. The RFID reader has read/write capabilities and reads the digital key of the RFID tag embedded, hidden or placed behind and, if valid, opens the lock. 
         [0020]    In the above-described scenario, the check-in process and guest interaction with NFC phone and lock is the same as if the NFC device were operating in the card emulation mode. Furthermore, the user is allowed to perform remote check-in processes with their NFC device, thereby obviating the need to visit the front desk of the hotel upon arriving at the hotel. 
         [0021]    This solution will work on almost all existing and future NFC device. It is independent of MNOs&#39; control or influence over NFC card emulation mode. Further still, the proposed solution can work with locks and devices that already can read a RFID tag (e.g., legacy readers). 
         [0022]    In one embodiment, a method of operating an access control system, the method comprising: 
         [0023]    receiving a key at a Near Field Communications (NFC) device; 
         [0024]    storing the key in memory of the NFC device; 
         [0025]    presenting the NFC device to a Radio Frequency Identification (RFID) reader located in proximity to a point of access control; 
         [0026]    while the NFC device is presented to the RFID reader, writing the key to an RFID tag that is positioned in proximity to the RFID reader; 
         [0027]    reading the key from the RFID tag with the RFID reader; 
         [0028]    comparing the key read from the RFID tag with one or more valid keys; and 
         [0029]    based on the comparison of the key read from the RFID tag, making an access control decision for the NFC device. 
         [0030]    In another aspect of the present disclosure, the RFID reader may be enabled to read and store the Unique Identifier (UID) of the tag in proximity therewith, thereby allowing the RFID reader to use or specifically control the permanently-placed tag, if necessary. By way of example, the RFID reader can use the UID and the anti-collision mechanisms specified in the above mentioned RFID standards to “shut down” the RFID tag to avoid communication disturbance with other tags, by example RFID tags embedded into cards and used by guests that do not have NFC device, or NFC devices that use NFC card emulation. 
         [0031]    In another aspect of the present disclosure, the RFID reader is enabled to write back data to the RFID tag in order to exchange information with an NFC device (e.g., a phone). In this way, the RFID reader can utilize the NFC device as a mode of transporting information back to a host controller of an access control system. As an example, this exchange of information can be leveraged to delete the digital key in the RFID tag from a list of valid keys in the access control system, thereby preventing attacks on the digital key by making keys less available. 
         [0032]    The present disclosure will be further understood from the drawings and the following detailed description. Although this description sets forth specific details, it is understood that certain embodiments of the invention may be practiced without these specific details. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]      FIG. 1  is a perspective view of an access control system in accordance with embodiments of the present disclosure; 
           [0034]      FIG. 2  is a partially exploded view of  FIG. 1 , showing the face plate of the RFID reader removed and further showing an RFID tag positioned underneath the face plate; 
           [0035]      FIG. 3A  is a perspective view of the inside surface of an RFID face plate, further showing an RFID tag mounted to the face plate; 
           [0036]      FIG. 3B  is a rear elevation view of the reader face plate of  FIG. 3A ; 
           [0037]      FIG. 4  is a block diagram of components of an RFID tag in accordance with embodiments of the present disclosure; 
           [0038]      FIG. 5  is a block diagram of component of an NFC device in accordance with embodiments of the present disclosure; 
           [0039]      FIG. 6  is a flow chart depicting a method of performing remote check-in with an NFC device in accordance with embodiments of the present disclosure; 
           [0040]      FIG. 7  is a flow chart depicting a method of obtaining access to an access point within an access control system using an NFC device in accordance with embodiments of the present disclosure; 
           [0041]      FIG. 8  is a flow chart depicting an anti-collision method in accordance with embodiments of the present disclosure; and 
           [0042]      FIG. 9  is a flow chart depicting a data management method for an access control system in accordance with embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0043]    Access control in a hotel is used as examples in the scenarios below. These examples are for illustrative purposes only. It will be readily appreciated by those of skill in the art, upon reading this disclosure, that the described solution has wide spread applicability in not only all access control environments, but other applications. The ensuing description will provide those skilled in the art with an enabling description for implementing the described embodiments. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention. 
         [0044]    As can be seen in  FIGS. 1-4 , an access control system may include components that secure a physical point of entry on premises. In the depicted example, the physical point of entry corresponds to a door  100  with a lock  104  integrated therein. It should be appreciated that other embodiments may comprise a lock mechanism external to a door or on a doorjamb. 
         [0045]    The lock mechanism  104  is capable of being actuated with a handle  108  in a known fashion. It should be appreciated that the handle  108  may be replaced with any other similar mechanism known in the art (e.g., knob, insertable mechanical key, etc.). However, as will be described herein, the handle  108  may only be engaged with the lock mechanism  104  if a valid key is read at an RFID reader  112 , which is also shown to be mounted to the door  100 . 
         [0046]    As used herein, a valid key may correspond to a data structure exchanged between an RFID device (e.g., an NFC-capable device  120 , RFID tag  116 , a different RFID tag, etc.) and the RFID reader  112 . As is known in the access control arts, an access control key can be provided in any number of variations; however, for ease of discussion, a key exchanged between the RFID reader  112  and NFC device  120  may correspond to any data structure (e.g., encrypted, unencrypted, etc.) that is capable of being stored in computer memory and exchanged via RFID/NFC protocols. Thus, a key can be exchanged between the NFC device  120  and RFID reader  112  using one or more NDEF records or messages and the key may correspond to a collection of bits. In addition to requiring a valid key, the RFID reader  112  may be equipped to require additional inputs (e.g., passwords, PINs, fingerprints, etc.) to prove that a holder of the NFC device  120  also knows something or is someone with authority to open the door  100 . Such authentication methods are known as dual-factor authentication methods. 
         [0047]    In some embodiments, the NFC device  120  may obtain a valid key from a hotel service or similar security administrator of the premises on which the door  100  is mounted. As an example, the NFC device  120  may obtain a valid key or collection of keys from a hotel system in a manner similar to that described in one or more of U.S. Patent Publication Nos. 2011/0187493 and 2006/022490, filed Jan. 29, 2010 and Apr. 3, 2006, respectively, each of which are hereby incorporated herein by reference in their entirety. 
         [0048]    The NFC device  120 , when presented to the RFID reader  112 , may have the NFC functionality contained therein become activated (e.g., by inductive coupling due to the RF field produced by the RFID reader  112 ). Once the NFC device  120  is within proximity of the RFID reader  112  and has become activated, the NFC device  120  enters a read/write mode of operation. While in this mode of operation, the NFC device  120  writes the key or series of keys stored thereon to the RFID tag  116 . 
         [0049]    Upon receiving the keys from the NFC device  120 , the tag  116  temporarily stores the keys in its own memory. Subsequently, the RFID reader  112  reads the keys from the RFID tag  116 , thereby enabling the RFID reader  112  to obtain keys from the NFC device  120  without requiring the NFC device  120  to operate in a card emulation mode. Specifically, the RFID device  120  is able to communicate keys and other data to the RFID reader  112  via the RFID tag  116 . 
         [0050]    As can be seen in  FIG. 2 , the RFID tag  116  may be positioned behind a face plate  204  of the RFID reader  112 . By placing the RFID tag  116  in this particular position, the RFID tag  116  will remain in proximity with the RFID reader  112 ; thus, when the NFC device  120  is presented to the RFID reader  112 , the NFC device  120  is also placed within communication range of the RFID tag  116 . 
         [0051]    It should be appreciated that the RFID tag  116  does not necessarily need to be positioned behind a face plate  204  of the RFID reader  112 ; however, such a location provides a convenient mounting location for the RFID tag  116 . In other embodiments, however, the RFID tag  116  may correspond to a sticker of the like that is positioned adjacent to the RFID reader  112 . 
         [0052]      FIGS. 3A and 3B  show additional details regarding the relative arrangement of the RFID tag  116  and the RFID reader  112 . In particular, it may be advantageous to offset the RFID tag  116  relative to the center of the RFID reader&#39;s antenna.  FIG. 3B  shows in detail how a center of the tag antenna  308  can be offset relative to a center of the reader antenna  304 . This offsetting may be advantageous to minimize the parasitic capacitance between the antennas  304 ,  308 . Additional details of such a feature are described in U.S. Pat. No. 7,439,862, the entire contents of which are hereby incorporated herein by reference. 
         [0053]    Although  FIG. 3B  does not show the reader antenna, the center of the reader antenna  304  may substantially align with a center of the face plate  204 . As shown in  FIG. 2 , the electronic components  208  of the RFID reader  112  may be positioned substantially within a center of the reader housing. The reader antenna may wrap around the outer edges or perimeter of the housing and, therefore, be centered about the center of the face plate  204 . On the other hand, the RFID tag  116  can be offset within the housing of the reader since the RFID tag  116  is smaller than electronic components  208  of the RFID reader  112 . 
         [0054]    It should be appreciated that the RFID tag  116  can be held within the housing of the RFID reader  112  using any type of securement mechanism. As some non-limiting examples, the RFID tag  116  can be held in the housing of the RFID reader  112  using friction fittings, glue, adhesives, double-sided tape, fasteners (e.g., nuts, bolts, screws, etc.), any combination thereof, or any other retainer device. In some embodiments, the RFID tag  116  is releasably mounted in the housing of the RFID reader  112  whereas in other embodiments the RFID tag  116  can be permanently fixed in the housing (e.g., by embedding components of the RFID tag  116  into the plastic of the housing. 
         [0055]    With reference now to  FIG. 4 , components of the RFID tag  116  will be described in accordance with embodiments of the present disclosure. The RFID tag  116  may include one or more Integrated Circuits (ICs)  404 , a switch  408 , a control circuit  412 , a connector  416 , and an antenna  420 . In some embodiments, the components of the RFID tag  116  may be contained in a known tag form factor such as a card-type structure, a key fob, a sticker, or the like. Although not depicted, the RFID tag  116  may also comprise an internal power source (e.g., battery, solar cell and converter, etc.), in which case the RFID tag  116  may be referred to as an active tag. Passive tags, on the other hand, do not comprise an internal power source and, instead, rely on power from inductive coupling with another RF field (e.g., a field generated by an NFC device  120  and/or RFID reader  112 ). 
         [0056]    The IC  404  may correspond to one or many ICs or IC components. In particular, the IC  404  may comprise digital circuitry that generates and transmits a predetermined response when activated by an external RF field. In some embodiments, the IC  404  may include memory in addition to processing circuitry. As an example, the IC  404  may comprise memory sufficient to store access control keys, encryption keys, cryptographic algorithms, and combinations thereof. 
         [0057]    In some embodiments, the IC  404  also provides security functions to the RFID tag  116 . As an example, the IC  404  may provide the RFID tag  116  with an encryption algorithm, thereby enabling the RFID tag  116  to exchange encrypted communications with other devices, such as the RFID reader  112  and NFC device  120 . Encryption keys and the like may also be stored in the IC  404  in a secure fashion. 
         [0058]    The switch  408  may by an optional component. In some embodiments, the IC  404  may be connected directly to the antenna  420 , in which case the RFID tag  116  does not require a switch  408  and control circuit  412 . In other embodiments, the switch  408  may reside between the IC  404  and antenna  420  and be operated by the control circuit  412 . As an example, and as described above, the antenna  420  may introduce noise into a system where the RFID reader  112  is attempting to read an external tag or attempting to directly read a key from the NFC device  120  operating in an emulation mode. If this becomes the case, the RFID reader  112  may be configured to provide instructions to the control circuit  412  via the connector  416  to disconnect the IC  404  from the antenna  420  via actuation of the switch  408 . In other words, if the RFID reader  112  determines that too much noise is being introduced by the RFID tag  116 , then the RFID reader  112  may ask the control circuit  412  to move the switch  408  from a closed position to an open position. 
         [0059]    The switch  408  may comprise a logical and/or physical switch. As an example, the switch  408  may correspond to a physical switch that moves between connectors of the antenna  420  and IC  404 . Alternatively, the switch  408  may correspond to a software switch, digital switch, or the like. 
         [0060]    The control circuit  412  may comprise a micro-controller  412  that contains logic capable of coupling and decoupling the IC  404  and antenna  420  via actuation of the switch  408 . The control circuit  412  may receive its instructions from the connector  416 , which provides an interface between the RFID tag  116  and RFID reader  112 . The connector  416  may comprise a wired port or a wireless interface (e.g., a second antenna) between the RFID tag  116  and RFID reader  112 . 
         [0061]    With reference now to  FIG. 5 , components of the NFC device  120  will be described in accordance with embodiments of the present disclosure. The NFC device  120  may correspond to a mobile communication device such as a cellular phone, smart phone, tablet, laptop, or any other device that is NFC-enabled. The NFC device  120  is depicted as comprising a processor  504 , memory  508 , an NFC interface  512 , and a network interface  516 . In some embodiments, the processor  504  may correspond to a plurality of processors, each configured to perform certain operations for the NFC device  120 . As an example, the NFC device  120  may have dedicated processors for its NFC functions and other functions. In some embodiments, the components of the NFC device  120  may be connected together via a data bus or similar architecture. Thus, although the components are depicted as being connected via the central process  504 , such an arrangement of components is not required. 
         [0062]    The processor  504  may correspond to a microprocessor, Central Processing Unit (CPU), collection of processors or CPUs, or the like. In some embodiments, the processor  504  may be configured to execute instructions stored in memory  508 , thereby providing functionality to the NFC device  120 . 
         [0063]    The memory  508  may comprise a number of modules or instruction sets (e.g., applications, drivers, etc.) stored therein. In some embodiments, the memory  508  may include volatile and/or non-volatile memory. As some non-limiting examples, the memory  508  may include an NFC module  520 , a browser  524 , a phone module  528 , an email module  532 , and an Operating System (O/S)  536 . The NFC module  520  may comprise instructions that, when executed by the processor  504 , enable the NFC functionality of the NFC device  120 . For instance, the NFC module  520  may be responsible for causing the NFC device  120  to operate in a card emulation mode, a read/write mode, and/or a peer-to-peer mode. The NFC module  520  may also correspond to a specific portion of memory where sensitive data (e.g., key(s), encryption algorithms, PINs, credit card numbers, payment authorization information, other transaction data, etc.) is securely stored on the NFC device  120 . As an example, the NFC module  520  may include a read/write protected area of memory and, in some instances, the memory location may be encrypted. It should be noted that the memory  508  may correspond to a memory location other than the secure element of the NFC device  120 , which is traditionally embodied as a SIM card or an embedded secure element where NFC data is stored in an encryption fashion, since this formal secure element will likely be controlled by the MNOs. Thus, the NFC module  520  may correspond to specific memory or memory locations in addition to providing the executable instructions for the processor  504 . 
         [0064]    When executed, the NFC module  520  may cause the processor  504  to exchange information with other devices according to known NFC protocols via the NFC interface  512 . In some embodiments, the NFC interface  512  may include a coil or antenna that creates an inductive coupling with other RF-enabled devices. The size of the NFC interface  512  may depend upon the overall size of the NFC device  120  as well as other antennas contained within the NFC device  120 . 
         [0065]    The other phone functionality of the NFC device  120  may be provided by the other modules  524 ,  528 ,  532  and O/S  536  stored in memory  508 . As examples, the O/S  536  may correspond to a mobile operating system specifically designed for smart phones or the like. Non-limiting examples of an O/S  536  include Android®, iOS®, BlackberryOS®, Windows®, Windows Mobile®, and the like. The O/S  536  may be responsible for providing the basic functionality of the phone (e.g., controlling user input and output functions, microphone functions, coordinating drivers, etc.) in addition to coordinating operations of the applications and other modules stored in memory  508 . 
         [0066]    The browser  524  may provide the NFC device  120  with the ability to browse the Internet, for example. The browser  524 , in some embodiments, corresponds to an application that enables the NFC device  120  to exchange information with servers and other data providers over a communication network using known Internet Protocols (e.g., HTTP, HTML, XML, etc.). Non-limiting examples of browsers  524  include Internet Explorer®, Safari®, Google Chrome®, mobile versions thereof, etc. 
         [0067]    The phone module  528  may provide the NFC device  120  with the ability to initiate and respond to calls (e.g., voice calls, video calls, multi-media collaborations, etc.). The phone module  528  may also enable a user to perform advanced communication functions such as accessing voicemail, establishing conference calls, etc. 
         [0068]    The email module  532  may provide the NFC device  120  with the ability to exchange electronic messages with other devices over a communication network. As examples, the email module  532  may specifically support email communications. It should also be appreciated that the email module  532  may support other types of communications such as social media communications (e.g., Facebook®, Twitter®, etc.), Short Message Service (SMS) messaging, Multimedia Messaging Services (MMS), data messages transmitted over the Internet (e.g., in accordance with an IP protocol), and so on. 
         [0069]    Communications between the NFC device  120  and a broader communication network may be facilitated by the network interface  516 , which may actually include several interfaces to different networks or network types. For instance, the network interface  516  may comprise a cellular network interface that enables the NFC device  120  to interact with a cellular network, which is usually provided by a MNO. The network interface  516  may alternatively or additionally include an 802.11N interface (e.g., Wi-Fi interface), a Universal Serial Bus (USB) port, or any other wired or wireless interface to the communication bus of the NFC device  120 . 
         [0070]    With reference now to  FIG. 6 , a method of obtaining one or more keys at an NFC device  120  will be described in accordance with embodiments of the present disclosure. The method begins with a user or guest coordinating a remote check-in for their mobile device (e.g., NFC device  120 ) (step  604 ). Coordination of the remote check-in may be effected with the NFC device  120  itself or the user may coordinate the remote check-in from some other computer. In the latter scenario, the user may provide the server or provider of the keys with the telephone number for the NFC device  120 , thereby allowing the provider of the keys to target the NFC device  120 . 
         [0071]    Thus, the method continues with the provider of the keys (e.g., hotel, access control system administrator, etc.) sending the key(s) to the NFC device  120 . The key(s) are subsequently received by the NFC device  120  (step  608 ). In some embodiments, the key(s) are received via the network interface  516 , for example, when the key(s) are sent via SMS, MMS, email, or the like. 
         [0072]    Upon receiving the key(s), the NFC device  120  stores the key(s) in a secure (e.g., encrypted) area of its memory  508  (step  612 ). In some embodiments, the key(s) may be stored in a secure element of the NFC device  120 . 
         [0073]    With reference now to  FIG. 7 , a method of operating an NFC device  120  in a read/write mode to obtain access to a secure point of access will be described in accordance with embodiments of the present disclosure. The method begins when the NFC device  120  is presented to an RFID reader  112  (step  704 ). Upon entering an active zone of the RFID reader  112  (e.g., a space in which the RF field produced by the RFID reader  112  is sufficient to couple with or power the NFC device  120  (or any other passive RFID tag)), the NFC module  520  is activated and causes the NFC device  120  to begin operating in an NFC mode of operation. In this example, the NFC module  520  causes the NFC device  120  to begin operating in a read/write mode. 
         [0074]    Thus, the method continues with the NFC module  520  obtaining the necessary key(s) from their storage location (e.g., from the memory  508  of the NFC device  120 ). The key(s) are then written to the RFID tag  116  by the NFC device  120  (step  708 ). Because the RFID tag  116  is located in proximity with the RFID reader  112 , the key(s) are written to the RFID tag  116  while the RFID reader  112  and NFC device  120  are coupled to one another. Once written to the RFID tag  116 , the key(s) are stored in the memory of the RFID tag  116 . For example, the key(s) may be stored in volatile or non-volatile memory of the RFID tag  116 , which may be incorporated in the IC or separate therefrom. 
         [0075]    The NFC device  120  may also read some data back from the RFID tag  116 . In particular, the NFC device  120  may read back the RFID tag&#39;s  116  UID and any other information that identifies the RFID tag  116  and/or RFID reader  112  in a substantially unique fashion. The information read back from the RFID tag  116  can then be transmitted by the NFC device  120  to a central system (e.g., hotel front desk, guest management system, control panel, central server, etc.), thereby notifying the central system of the guest&#39;s arrival. In some embodiments, status information for the RFID reader  112  may also be updated in a centralized access control log based on the information received from the RFID tag  116  via the NFC device  120 . 
         [0076]    The RFID reader  112  then reads the key(s) from the RFID tag  116  (step  712 ). This process is completed in a known fashion, for example, by following one or more of the ISO standards mentioned above. Upon obtaining the key(s) from the RFID tag  116 , the RFID reader  112  analyzes the key(s) or access control information contained therein to make an access control decision based on the key(s) and/or their contents (step  716 ). It should also be appreciated that the RFID reader  112  may analyze the UID of the tag that provided the keys. If the UID of the tag does not match the UID of the tag paired with or trusted by the RFID reader  112 , then the keys may be rejected, even if the keys correspond to valid keys. In some embodiments, the RFID reader  112  analyzes access control information contained within the keys to determine whether access should be granted or not. It may also be possible that the RFID reader  112  compares the key(s) received from the RFID tag  116  with a list of valid keys stored in its local memory. In some embodiments, the RFID reader  112  sends the key(s) to a control panel located remote from the RFID reader  112  so that the control panel can analyze the keys and/or compare the received key(s) with valid or invalid keys. 
         [0077]    If the received key(s) are determined to be authorized keys (e.g., the key is valid and useable for the RFID reader  112  during the time at which the key was read by the RFID reader  112 ), then the RFID reader  112  will open the lock mechanism  104  or engage the lock mechanism  104  with the handle  108 , thereby allowing a user to open the lock mechanism  104  (step  720 ). If the received keys are not determined valid (or were determined to be invalid), then the RFID reader  112  may not perform any action or the RFID reader  112  may proactively indicate that the key(s) read from the RFID tag  116  were invalid. For instance, the RFID reader  112  may sound an alarm, send a notification to security personnel, store information in an activity log about the invalid keys, light an indicator, etc. 
         [0078]    It should be noted that once the RFID reader  112  obtains and analyzes the keys received from the NFC device  120  via the RFID tag  116 , the RFID reader  112  may cause the keys to be deleted/disabled/overwritten from the memory of the RFID tag  116 . This may be done by sending one or more of a delete, disable, or overwrite command back to the RFID tag  116 . 
         [0079]    With reference now to  FIG. 8 , an anti-collision method will be described in accordance with embodiments of the present disclosure. The method begins when the RFID reader  112  reads data from a local RFID tag  116  (step  804 ). In some embodiments, the “local tag” may correspond to the RFID tag  116  that is permanently or semi-permanently positioned in proximity with the RFID reader  112 . More specifically, the local tag may correspond to an RFID tag  116  that is mounted inside of the housing of the RFID reader  112  or that has been affixed near the RFID reader  112  to support the access control methods described herein. 
         [0080]    The information read from the local RFID tag  116  may include a UID of the local RFID tag  116 . Upon receiving the UID of the local RFID tag  116 , the RFID reader  112  may store the UID of the local RFID tag  116  in its own memory (step  808 ). The UID of the local RFID tag  116  may be stored in volatile or non-volatile memory. In some embodiments, the UID of the tag is paired with the specific RFID reader  112  with which it is associated (e.g., by virtue of being installed in the housing of the specific RFID reader  112 ). This ensures that only keys read from the paired RFID tag  116  (e.g., the local RFID tag  116 ) are accepted. In other words, if the RFID reader  112  reads a key from a tag other than the local RFID tag  116 , the RFID reader  112  may either reject the key or require additional information to accept the key. 
         [0081]    The method continues when the RFID reader  112  detects a second tag (e.g., a tag different from the local RFID tag  116 ) or when the RFID reader  112  detects an NFC device operating in a card emulation mode (step  812 ). Upon detecting such a device, the RFID reader  112  may instruct the local RFID tag  116  to shut down or stop RF communications for a predetermined amount of time (e.g., 1 minute, 30 seconds, etc.) (step  816 ). In some embodiments, the RFID reader  112  is capable of communicating such instructions directly to the local RFID tag  116  because it has obtained the local RFID tag&#39;s  116  UID. Upon receiving instructions to disable RF communications, the local RFID tag  116  may disengage or disconnect the IC  404  from the antenna  420  via actuation of the switch  408 . 
         [0082]    In this anti-collision method, the control circuit  412  of the local RFID tag  116  may have communications with the RFID reader  112  via a service interface (e.g., connector  416 ) of the RFID reader  112 . Thus, in addition to receiving control instructions from the RFID reader  112  via the connector  416 , the local RFID tag  116  may further receive power from the RFID reader  112  via the connector  416 . 
         [0083]    With reference now to  FIG. 9 , a data management method will be described in accordance with at least some embodiments of the present disclosure. The method begins with the RFID reader  112  writing data to the local RFID tag  116  (step  904 ). The data written to the local RFID tag  116  can include any type of access control data. Non-limiting examples of data that can be written to the local RFID tag  116  include keys, tag UIDs, encryption keys, cryptographic algorithms, access logs (e.g., historical records of access attempts at the RFID reader  112 ), portions of access logs, combinations thereof, etc. 
         [0084]    The data received at the local RFID tag  116  is then stored in memory of the RFID tag  116 . Subsequently, the data stored on the local RFID tag  116  can be read by the NFC device  120  operating in a read/write mode of operation (step  908 ). The information obtained by the NFC device  120  can then be communicated to a central access control system, for example by transmission over a communication network (step  912 ). As an example, the RFID reader  112  may correspond to a stand-alone reader and may, therefore, not have any direct connectivity with a control panel or similar access control system backend/host. In this scenario, the stand-alone reader can utilize the communication capabilities of the NFC device  120  to share information with the access control system backend. Upon communicating the information to the NFC device  120 , the local RFID tag  116  can optionally delete the information stored thereon (step  916 ). Furthermore, the keys communicated between the RFID reader  112  and NFC device  120  in any of the methods described herein can be deleted from memory after a predetermined amount of time to ensure that the keys are not copied and used without permission. 
         [0085]    As can be appreciated, RFID tags can be embedded in to all kind of media such as cards, passports, wristbands, stickers, etc. The present disclosure is not limited to any particular RFID tag format or embodiment, but can be used with any format of an RFID tag. 
         [0086]    Furthermore, the above-described system will work with hotel employees in addition to working for hotel guests. In the case of employees, “check-in” becomes date of employment and check-out is when employment with the company stops or check-in and check-out may occur on a daily basis (e.g., an employee is given a new key on a daily basis, thereby ensuring up-to-date security policies for employees). 
         [0087]    The front desk device, identified above, is only an example and represents any device that can be used to put information on a RFID tag. The device that places information on an RFID tag does not necessarily need to be located at a front desk of a hotel; instead, such a device can be located anywhere without departing from the scope of the present disclosure. 
         [0088]    The disclosed system may be adopted in any type of RFID access control setting, including but not limited to residential, office, hotel, garage, public transportation, etc. It may also be used in payment and ticketing systems. 
         [0089]    It should also be appreciated that the RFID reader can be placed anywhere, on the lock, on the wall next to the lock, in elevators without a lock, gate controllers, etc. 
         [0090]    In the foregoing description, for the purposes of illustration, methods were described in a particular order. It should be appreciated that in alternate embodiments, the methods may be performed in a different order than that described. It should also be appreciated that the methods described above may be performed by hardware components or may be embodied in sequences of machine-executable instructions, which may be used to cause a machine, such as a general-purpose or special-purpose processor (GPU or CPU) or logic circuits programmed with the instructions to perform the methods (FPGA). These machine-executable instructions may be stored on one or more machine readable mediums, such as CD-ROMs or other type of optical disks, floppy diskettes, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, flash memory, or other types of machine-readable mediums suitable for storing electronic instructions. Alternatively, the methods may be performed by a combination of hardware and software. 
         [0091]    Specific details were given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. 
         [0092]    Also, it is noted that the embodiments were described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function. 
         [0093]    Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium such as storage medium. A processor(s) may perform the necessary tasks. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc. 
         [0094]    While illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.