Patent Publication Number: US-2022228399-A1

Title: Tamper alarm for electronic lock

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent Ser. No. 16/425,491, filed May 29, 2019; which claims priority from U.S. Provisional Patent Application No. 62/677,499, filed on May 29, 2018, the disclosures of which are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     Electronic locks have gained increasing acceptance and widespread use in residential and commercial markets. These locksets control ingress through doors in a building by requiring certain credentials. For example, these locksets typically include a control circuit that determines whether to unlock the lockset based on credentials provided by the user. In some cases, the credentials and/or commands may be provided to the lockset via a keypad. 
     Unauthorized tampering with the electronic lock can indicate a potential break-in or the existence of an unauthorized individual proximate to the electronic lock. However, oftentimes the electronic lock owner is notified of this tampering after the fact or not at all. Therefore, improvements in electronic lock design are desired. 
     SUMMARY 
     The present disclosure relates generally to electronic locks. In one possible configuration, and by non-limiting example, based at least in part on a characteristic of a keypad input event received at a keypad, the processing unit of the electronic lock indicates if a tampering event exists. 
     In one example of the present disclosure, an electronic lock is disclosed. The electronic lock includes a latch assembly that includes a bolt that is movable between an extended position and a retracted position. The electronic lock includes a keypad for receiving a keypad input event. The electronic lock includes a processing unit being configured to control the movement of the bolt between the extended position and the retracted position responsive to receiving a valid keypad input event. The processing unit is configured to capture the keypad input event. Based at least in part on a characteristic of the keypad input event, the processing unit indicates if a tampering event exists. The characteristic includes at least one of an input location on the keypad, an input duration on the keypad, and an input timestamp. 
     In another example of the present disclosure, a method of operating an electronic lock is disclosed. The method includes receiving a keypad input event via a keypad. Upon receipt of a valid keypad input event, a bolt is moved between an extended position and a retracted position. The method includes determining the existence of a tampering event based at least in part on a characteristic of the keypad input event. The characteristic includes at least one of an input location on the keypad, input duration on the keypad, and an input timestamp. The method includes activating a tamper alarm after it is determined a tampering event exists. 
     In a further example, an electronic lock includes a latch assembly including a bolt movable between an extended position and a retracted position, and an exterior assembly including a tamper sensing device, such as a capacitance or resistance sensor. The electronic lock includes a processing unit configured to control the movement of the bolt between the extended position and the retracted position responsive to receiving a valid input at the user input device; wherein the processing unit is configured to capture the input event. Based at least in part on a characteristic of the input event, the processing unit indicates if a tampering event exists, wherein the characteristic includes at least one of an input type, an input location, an input duration, and an input timestamp on the tamper sensing device. 
     A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings are illustrative of particular embodiments of the present disclosure and therefore do not limit the scope of the present disclosure. The drawings are not to scale and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the present disclosure will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements. 
         FIG. 1  illustrates a schematic side view of an electronic lock, according to one example of the present disclosure. 
         FIG. 2  illustrates a rear perspective view of a portion of the electronic lock of  FIG. 1 . 
         FIG. 3  illustrates a front perspective view of a portion of the electronic lock of  FIG. 1 . 
         FIG. 4  illustrates a schematic representation of an example system utilizing the electronic lock of  FIG. 1 . 
         FIG. 5  illustrates a schematic representation of the electronic lock of  FIG. 1 . 
         FIG. 6  illustrates an example operation of the electronic lock of  FIG. 1 . 
         FIG. 7  illustrates another example operation of the electronic lock of  FIG. 1 . 
         FIG. 8  illustrates an example keypad input event of the electronic lock of  FIG. 1 . 
         FIG. 9  illustrates another example keypad input event of the electronic lock of  FIG. 1 . 
         FIG. 10  illustrates another example keypad input event of the electronic lock of  FIG. 1 . 
         FIG. 11  illustrates a schematic exploded view of an electronic lock according to an alternative embodiment of the present disclosure. 
         FIG. 12  illustrates an example operation of the electronic locks of  FIG. 1  and  FIG. 11 . 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the appended claims. 
     The electronic lock disclosed herein includes a number of advantages. The electronic lock is configured to provide an indication of tampering with an electronic lock, including tampering with a keypad of the electronic lock, in the form of, for example, a tamper alarm. The electronic lock can recognize when someone is physically tampering with the keypad (i.e., physically drilling into the electronic lock or keypad, or using other measures to physically manipulate the keypad). The electronic lock can also recognize when someone is trying to input an access code but does so inaccurately (i.e., depresses buttons adjacent to the correct button), provides too long of an input on the keypad, and/or attempts to input an access code outside of a normal window of operation of the electronic lock. 
     In some examples, an electronic lock can capture a keypad input event, for example, a user inputting an access code on the keypad, and determine if a tampering event exists based at least in part on characteristics of the keypad input event. The electronic lock can utilize characteristics of the keypad input event that include at least one of an input location on the keypad, an input duration on the keypad, and an input timestamp. In some examples, the electronic lock determines if a tampering event exists by comparing the keypad input event to past keypad input events and, if the keypad input event does not closely enough match past keypad input events, the electronic lock will trigger a tamper alarm. 
     In still other aspects, a tampering event can be determined based on the electronic lock detecting other types of interaction with the lock that may be identifiable as tampering. For example, physical tampering activities, such as drilling through or removing an escutcheon or face plate of an electronic lock, may indicate a tampering event to a circuit of the electronic lock, e.g., based on a sensor detecting the tampering event or based on a change in electrical characteristic of an aspect of the electronic lock. Still further, a tampering event may be detectable based on an unauthorized device attempting to connect to that electronic lock to actuate the lock. Accordingly, a tampering event may be detected based on either a keypad input event, a physical tampering event, or a connection attempt causing a tamper alarm to be triggered. 
     This disclosure generally relates to an electromechanical lock with certain features. The term “electronic lock” is broadly intended to include any type of lockset that uses electrical power in some manner, including but not limited to, electronic deadbolts, electronic lever sets, etc. This disclosure encompasses the integration of one or more features described herein into any type of electronic lock and is not intended to be limited to any particular type of electronic lock. 
       FIGS. 1-3  illustrate an electronic lock  100  mounted to a door  102 , according to one example of the present disclosure. The door has an interior side  104  and an exterior side  106 . The electronic lock  100  includes an interior assembly  108 , an exterior assembly  110 , and a latch assembly  112 . The latch assembly  112  is shown to include a bolt  114  that is movable between an extended position (locked) and a retracted position (unlocked, shown in  FIGS. 1-3 ). Specifically, the bolt  114  is configured to slide longitudinally and, when the bolt  114  is retracted, the door  102  is in an unlocked state. When the bolt  114  is extended, the bolt  114  protrudes from the door  102  into a door jamb (not shown) to place the door in a locked state. 
     In some examples, the interior assembly  108  is mounted to the interior side  104  of the door  102 , and the exterior assembly  110  is mounted to the exterior side  106  of the door  102 . The latch assembly  112  is typically at least partially mounted in a bore formed in the door  102 . The term “outside” is broadly used to mean an area outside the door  102  and “inside” is also broadly used to denote an area inside the door  102 . With an exterior entry door, for example, the exterior assembly  110  may be mounted outside a building, while the interior assembly  108  may be mounted inside a building. With an interior door, the exterior assembly  110  may be mounted inside a building, but outside a room secured by the lock  100 , and the interior assembly  108  may be mounted inside the secured room. The lock  100  is applicable to both interior and exterior doors. 
     Referring to  FIG. 2 , the interior assembly  108  can include a processing unit  116  (shown schematically) containing electronic circuitry for the electronic lock  100 . In some examples, the interior assembly  108  includes a manual turnpiece  118  that can be used on the interior side  104  of door  102  to move the bolt  114  between the extended and retracted positions. 
     The processing unit  116  is operable to execute a plurality of software instructions (i.e., firmware) that, when executed by the processing unit  116 , cause the electronic lock  100  to implement the methods and otherwise operate and have functionality as described herein. The processing unit  116  may comprise a device commonly referred to as a microprocessor, central processing unit (CPU), digital signal processor (DSP), or other similar device and may be embodied as a standalone unit or as a device shared with components of the electronic lock  100 . The processing unit  116  may include memory for storing the software instructions, or the electronic lock  100  may further comprise a separate memory device for storing the software instructions that is electrically connected to the processing unit  116  for the bi-directional communication of the instructions, data, and signals therebetween. 
     Referring to  FIG. 3 , the exterior assembly  110  can include a keypad  120  for receiving a user input and/or a keyway  122  for receiving a key (not shown). The exterior side  106  of the door  102  can also include a handle  124 . In some examples, the exterior assembly  110  includes the keypad  120  and not the keyway  122 . In some examples, the exterior assembly  110  includes the keyway  122  and not the keypad  120 . In some examples, the exterior assembly  110  includes the keyway  122  and the keypad  120 . When a valid key is inserted into the keyway  122 , the valid key can move the bolt  114  between the extended and retracted positions. When a user inputs a valid code into the keypad  120 , the bolt  114  is moved between the extended and retracted positions. 
     In some examples, the exterior assembly  110  is electrically connected to the interior assembly  108 . Specifically, the keypad  120 , and associated exterior electronic circuitry  117 , is electrically connected to the interior assembly  108 , specifically to the processing unit  116 , by, for example, an electrical cable  115  that passes through the door  102 . The electrical connection between the exterior assembly  110  and the interior assembly  108  allows the processing unit  116  to communicate with other features included in the exterior assembly  110 . When the user inputs a valid code via keypad  120  that is recognized by the processing unit  116 , an electrical motor is energized to retract the bolt  114  of latch assembly  112 , thus permitting door  102  to be opened from a closed position. 
     The keypad  120  can be used to initiate a process to lock/unlock the lock and/or otherwise provide input. The keypad  120  can be any of a variety of different types of keypads. The keypad  120  can be one of a numeric keypad, an alpha keypad, and/or an alphanumeric keypad. The keypad  120  can have a plurality of characters  126  displayed thereon. For example, the keypad  120  can include a plurality of buttons that can be mechanically actuated by the user (e.g., physically pressed). In some examples, the keypad  120  includes a touch interface  128 , such as a touch screen or a touch keypad, for receiving a user input. The touch interface  128  is configured to detect a user&#39;s “press of a button” by contact without the need for pressure or mechanical actuation. An example of the touch interface is described in U.S. Pat. No. 9,424,700 for an “ELECTRONIC LOCK HAVING USAGE AND WEAR LEVELING OF A TOUCH SURFACE THROUGH RANDOMIZED CODE ENTRY,” which is hereby incorporated by reference in its entirety. 
     In a further example embodiment, the electronic lock  100  includes other types of touch activation capability. In some embodiments, for example, the entire outside cover of the lock is touch sensitive and allows a user to touch the lock to activate various functions of the lockset. 
     In some examples, the electronic lock  100  can wirelessly communicate with external devices through a desired wireless communications protocol. In some examples, an external device can wirelessly control the operation of the electronic lock  100 , such as operation of the bolt  114 . The electronic lock  100  can utilize wireless protocols including, but not limited to, the IEEE 802.11 standard (Wi-Fi), the IEEE 802.15.4 standard (Zigbee and Z-wave), the IEEE 802.15.1 standard (Bluetooth®), a cellular network, a wireless local area network, near-field communication protocol, and/or other network protocols. In some examples, the electronic lock  100  can wirelessly communicate with networked and/or distributed computing systems, such as may be present in a cloud-computing environment. 
       FIG. 4  shows a schematic of an example system  200  utilizing the electronic lock  100 . As shown, a user  202  interacts with the electronic lock  100 , specifically the keypad  120 , to provide the electronic lock  100  with a keypad input event. The keypad input event occurs when the user  202  interacts with the keypad  120 . This interaction can include, but is not limited to, touching a single character  126  of the keypad  120 , touching a plurality of characters  126  of the keypad  120 , placing a drill bit on the keypad  120 , striking the keypad  120  with an object, and/or any other physical interaction with the keypad  120 . In some examples, the keypad input event can include the user  202  entering an access code into the keypad  120 . The access code can include a variety of different combinations of characters  126 . In some examples, the access code is a four digit numeric passcode. In some examples, electrical signals are generated by the keypad  120  during a keypad input event. In some examples, the electrical signals are generated upon contact with the touch interface  128 . In some examples, the electrical signals can represent a change in electrical capacitance and/or signals from an open to closed circuit, etc. 
     The electronic lock  100  is configured to analyze the keypad input event received at the keypad  120  and output a tamper alarm  204  if it is determined that the keypad input event has characteristics that are indicative of a tampering event. 
     A tampering event can occur when an unauthorized user attempts to gain access through the door  102  by way of tampering with the electronic lock  100 . A tampering event can include, but is not limited to, the unauthorized user attempting to enter the valid access code, using brute force on the electronic lock, electronically compromising the electronic lock (hacking), and/or any other action that is not aligned with normal authorized user&#39;s use of the electronic lock. 
     In some examples, the electronic lock  100  determines if a tampering event exists using the electronic circuitry of the electronic lock  100 , such as the processing unit  116 . In some examples, the processing unit  116  uses past keypad input events from the electronic lock  100  to determine the existence of a tampering event. 
     In other examples, the determination of a tampering event may occur over a distributed system  206  (e.g., a cloud-based computing system), where memory, data storage and retrieval, and various processing functions may be operated remotely from each other over a distributed computing network, such as the Internet or an intranet. In some examples, the distributed system  206  aggregates keypad input events (from a single user or a plurality of users) and performs machine learning to determine the existence of tampering events. In some examples, the distributed system  206  then communicates the possibility of a tampering event with the electronic lock  100  (e.g., the processing unit  116 ) so the electronic lock  100  can output the tamper alarm  204 . 
     The tamper alarm  204  can be in the form of a notification that indicates to the user  202  that a tampering event has taken place. In some examples, the tamper alarm  204  can be a visual and/or audio notification. In some examples, the tamper alarm  204  can be indicated on the electronic lock  100  itself, such as by a status light and/or an audible message on, or from, the interior or exterior assemblies  108 ,  110 . In some examples, the tamper alarm  204  can be output to a remote device, such as a mobile device  208  and appear as a notification on a display. In some examples, the tamper alarm  204  can be in the form of a notification in an application of the mobile device  208 . In other examples, the tamper alarm  204  can trigger the electronic lock  100  to perform secondary functions such as, disabling the operation of the electronic lock  100 , specifically the keypad  120 . 
       FIG. 5  is a schematic representation of the electronic lock  100  mounted to the door  102 . The interior assembly  108 , the exterior assembly  110 , and the latch assembly  112  are shown. 
     The exterior assembly  110  is shown to include the electronic circuitry  117  communicatively and electrically connected to the processing unit  116 . The exterior assembly  110  includes the keypad  120 . In some examples, the exterior assembly  110  includes an optional exterior antenna  130  usable for communication with a remote device and/or an optional camera  131 . In some examples, the exterior antenna  130  is utilized by the processing unit  116  to determine where a mobile device is located. However, such a feature is not required, but can add additional security. 
     In some examples, the camera  131  can be used to monitor the environment adjacent the exterior assembly  110 . In some examples, the camera  131  is capable of capturing still photos and/or video media and storing such media locally at the electronic lock  100  and/or in a remote location (i.e., the cloud). In some examples, when a tamper alarm is activated, the camera  131  can be used to simultaneously capture a photo/video of the environment adjacent the exterior assembly  110  to help the owner of the electronic lock  100  determine what (e.g., what person) the tamper alarm is associated with. In some examples, the electronic lock  100  is configured to send the capture from the camera  131  to the remote device  208  when a tamper alarm is activated. An example of an electronic lock with a camera is described in U.S. Patent Publication No. 2014/0267740 for an “ELECTRONIC LOCK WITH REMOTE MONITORING,” which is hereby incorporated by reference in its entirety. 
     As described above, the interior assembly  108  includes the processing unit  116 . The interior assembly  108  can also include a motor  132  and an optional interior antenna  134 . 
     As shown, the processing unit  116  includes a processor  136 , memory  138 , an RF circuit  140 , and a battery  142 . The processing unit  116  is located within the interior assembly  108  and is capable of operating the electronic lock  100 . 
     In some examples, the processor  136  can analyze whether or not a tampering event exists based on a set of preprogramed instructions (i.e., firmware) stored in the memory  138 . In some examples, the processing unit  116  is configured to capture a keypad input event from a user and store the keypad input event in the memory  138 . In some examples, the processor  136  analyzes at least one characteristic of the keypad input event to determine if a tampering event exists. In some examples, if the processor  136  determines if a tamper alarm exists, the processor  136  outputs the tamper alarm  204 . In some examples, the processor  136  can output the tamper alarm via the RF circuit  140 . In some examples, the processor  136  can process signals received from a variety of devices to determine whether the electronic lock  100  should be actuated. In some examples, the processor  136  receives a signal from the exterior antenna  130 , interior antenna  134 , or other sensor  135  (e.g., a motion sensor (not shown), camera  131 , or other sensor) and can validate received signals in order to actuate the electronic lock  100 . 
     The memory  138  can include any of a variety of memory devices, such as using various types of computer-readable or computer storage media. A computer storage medium or computer-readable medium may be any medium that can contain or store the program for use by or in connection with the instruction execution system, apparatus, or device. By way of example, computer storage media may include dynamic random access memory (DRAM) or variants thereof, solid state memory, read-only memory (ROM), electrically erasable programmable ROM, and other types of devices and/or articles of manufacture that store data. Computer storage media generally includes at least one or more tangible media or devices. Computer storage media can, in some examples, include embodiments including entirely non-transitory components. 
     In some examples, the processing unit  116  can include the RF circuit  140 . The RF circuit  140  is capable of providing at least one wireless communication protocol. In some examples, the processing unit  116  can communicate with a remote device via the RF circuit  140 . In some examples, the processing unit  116  can communicate with the distributed system  206  via the RF circuit  140 . In other examples still, the processing unit  116  can communicate with a remote server via the RF circuit  140 . The RF circuit  140  can include one or more wireless communication interfaces, e.g., Bluetooth, Wi-Fi (IEEE 802.11x protocols), or any other wireless communication interface capable of bidirectional wireless communication. In example embodiments, the RF circuit  140  can include a Bluetooth Low Energy (BLE) interface. In another example embodiment, the RF circuit  140  communicates with a router via Wi-Fi. The router may be a standard router connected to a network, located within the building. Alternatively, the RF circuit  140  may communicate with a router through a Zigbee communication protocol. Still further, the RF circuit  140  may communicate with a router through a Bluetooth communication protocol. 
     The interior assembly  108  also includes the battery  142  to power the electronic lock  100 . In one example, the battery  142  may be a standard single-use (disposable) battery. Alternatively, the battery  142  may be rechargeable. 
     The interior assembly  108  also includes the motor  132  that is capable of actuating the bolt  114 . In use, the motor  132  receives an actuation command from the processing unit  116 , which causes the motor  132  to actuate the bolt  114  from the locked position to the unlocked position or from the unlocked position to the locked position. In some examples, the motor  132  actuates the bolt  114  to an opposing state. In some examples, the motor  132  receives a specified lock or unlock command, where the motor  132  only actuates the bolt  114  if the bolt  114  is in the correct position. For example, if the door  102  is locked and the motor  132  receives a lock command, then no action is taken. If the door  102  is locked and the motor  132  receives an unlock command, then the motor  132  actuates the bolt  114  to unlock the door  102 . 
     As noted above, the optional interior antenna  134  may also be located in the interior assembly  108 . In some examples, the interior antenna  134  is capable of operating together with the exterior antenna  130  to determine the location of the mobile device  208 . In some examples, only a mobile device determined to be located on the exterior side  106  of the door  102  is able to unlock (or lock) the door  102 . This prevents unauthorized users from being located near the electronic lock  100  and taking advantage of an authorized mobile device that may be located on the interior side  104  of the door  102 , even though the authorized mobile device is not being used to unlock the door  102 . 
     In some embodiments, the electronic lock  100  is made of mixed metals and plastic, with engineered cavities to contain electronics and antennas. For example, in some embodiments, the electronic lock utilizes an antenna near the exterior face of the lockset, designed inside the metal body of the lockset itself. The metal body can be engineered to meet strict physical security requirements and also allow an embedded front-facing antenna to propagate RF energy efficiently. 
       FIG. 6  shows an example schematic representation of an operation  300  of the electronic lock  100 . The electronic lock  100  captures a keypad input event at step  302 . In some examples, the keypad input event is stored in the memory  138  of the processing unit  116 . In some examples, the keypad input event is stored with a plurality of characteristics associated therewith. The keypad input event characteristics can include, but are not limited to, an input location on the keypad  120 , an input duration on the keypad  120 , and an input timestamp. 
     In some examples, every time the user  202  interacts physically with the electronic lock  100 , the processing unit  116  stores a new keypad input event. In some examples, when the user  202  inputs an access code that contains four digits, the electronic lock  100  can capture four keypad input events. In other examples, the processing unit  116  can group such an access code entry action together as a single stored keypad input event that contains a plurality of keypad input sub-events. In some examples, the electronic lock captures a keypad input event every time an input is detected. For example, each keypad input event stored can include the following characteristics [location of the input; duration of the input; and time of the input]. An example keypad input event can be [“character 5”; “1 second”; “2018-06-02 08:02:30”]. Another example of a keypad input event can be [(“character 1”; “1 second”; “2018-06-02 08:02:30”); (“upper right corner”; “4 seconds”; “2018-06-02 08:02:32”); (“character 5”; “1 second”; “2018-06-02 08:02:40”]); ([“character 9”; “1 second”; “2018-06-02 08:02:45”]; [“character 0”; “1 second”; “2018-06-02 08:02:50”]. 
     The input location on the keypad  120  can be, for example, where the user  202  makes contact with a particular character  126  on the keypad  120 . For example, the input location of a keypad input event is a single character  126  (e.g., a “button” of the keypad). This indicates where the user  202  makes contact with the keypad  120 . In some examples, the input location on the keypad  120  is not associated with a particular character  126  of the keypad  120 . In some examples, the processing unit  116  can monitor input to areas of the keypad  120  that are not associated with characters  126  (i.e., boundary areas between characters, the edges of the keypad  120 , etc.). 
     The input duration on the keypad  120  can be, for example, how long the user  202  makes contact with the keypad  120 . For example, the input duration can be how long the user  202  make contact with a character  126  (i.e., presses a particular “button”) of the keypad  120 . 
     The time of the input on the keypad  120  can be, for example, a timestamp associated when a particular input is first sensed. In some examples, the timestamp can be in the format of ‘YYYY-MM-DD H:MM:SS.’ 
     The electronic lock  100  can be configured to store a plurality of historic keypad input events in the memory  138  of the processing unit  116 . In some examples, a sliding window is employed to determine the amount of keypad input events to store in the memory  138 . In some examples, the electronic lock  100  stores the keypad input events from a certain amount of historical days, for example, the last 30 days. In other examples, the electronic lock  100  stores a particular number of past keypad input events, for example, the last 200 keypad input events, regardless of when they occurred. In some examples, the amount of historical keypad input events that the electronic lock  100  stores can be altered based on the preference of the manufacturer of the electronic lock  100 , the size of the memory  138 , and/or preference of the user  202 . 
     Once the keypad input event is captured from the keypad  120  at step  302 , the keypad input event is analyzed at step  304 . In some examples, the processing unit  116 , specifically the processor  136 , analyzes the keypad input event. In other examples, the processing unit  116  transmits the keypad input event via the RF circuit  140  for remote analysis. In some examples, the analysis can be performed by the mobile device  208 . In other examples, the analysis can be performed by the distributed system  206 . 
     The analysis of the keypad input event can include, but is not limited to, comparing the keypad input event to past keypad input events, comparing the keypad input event to predetermined tampering event characteristics, and/or comparing the keypad input event to learned tampering event characteristics. 
     In some examples, the past historical input events are analyzed to create a normal use profile. The normal use profile can include information based off the historical keypad input events that indicate patterns in the usage of the electronic lock  100 . For example, a normal use profile might include information that the user  202  shows a pattern of using the electronic lock  100  around 8:00 AM and around 5:30 PM every weekday. In other examples, a normal use profile might include information that the user  202  has a normal input duration of no more than two seconds. In some examples, the user can manually alter the normal use profile, regardless of historical input events. 
     In some examples, the electronic lock can be programmed to include information regarding predetermined tampering event characteristics. For example, a characteristic indicative of a tampering event is an input duration of more than five seconds. In another example, a characteristic indicative of a tampering event is an input time between the hours of 12:00 AM and 5:00 AM. In another example still, a characteristic indicative of a tampering event is an input location on the corners and/or edges of the keypad  120 . In some examples, the processing unit  116  is configured to be updated with tamper alarm characteristics via the RF circuit (e.g., a definition and/or firmware update). 
     In some examples, the distributed system  206  can aggregate keypad input events from a single user or a plurality of users and utilize machine learning to produce learned tampering event characteristics. In some examples, users can provide an indication to the distributed system  206  that a particular keypad input event actually resulted in tampering. 
     At step  306 , based at least in part on a keypad input event characteristic, the electronic lock  100  determines if there has been a tampering event. If there has not been a tampering event, the electronic lock  100  performs no action and continues to operate as normal. 
     If the keypad input event does not match the normal use profile, and/or includes characteristics that match with the predetermined tamper characteristic and/or the learned tampering event characteristics, the processing unit  116  determines that a tampering event exists. Once there is a known existence of a tampering event, the processing unit  116  triggers the tamper alarm  204  at step  308 . In some examples, the processing unit  116  triggers a secondary action at step  310  in place of, or in addition to, the tamper alarm  204  if there is an existence of a tampering event. In some examples, the secondary action can include, but is not limited to, disabling the operation of the keypad  120 , disabling the operation of the electronic lock  100 , and/or notifying an external system (i.e., an alarm system). 
     In some examples, the user  202  can alter the sensitivity of the tendency of processing unit  116  to trigger the tamper alarm  204 . In some examples, the user  202  can selectively disable the processing unit  116 &#39;s ability to trigger the tamper alarm  204 . In some examples, the user  202  can alter the processing unit  116 &#39;s tendency to trigger the tamper alarm  204  between a variety of predetermined sensitivity levels. In some examples, the user  202  can alter the sensitivity of the processing unit  116  to trigger the tamper alarm  204  via the mobile device  208  in communication with the RF circuit  140  of the processing unit  116 . In some examples, the user  202  can alter the sensitivity of the processing unit  116  to trigger the tamper alarm  204  via a physical switch (not shown) located on the interior assembly  108  of the electronic lock  100 . 
     In some examples, when setting the sensitivity level at its highest setting, the processing unit  116  will trigger the tamper alarm  204  if the keypad input event does not match with high accuracy the normal use profile. In some examples, when setting the sensitivity level at its highest setting, the processing unit  116  will trigger the tamper alarm  204  if the keypad input event includes a single characteristic that matches a predetermined and/or learned tampering event characteristic. When the user  202  reduces the sensitivity, the processing unit  116  requires, for example, a less accurate match to the normal use profile and allows more than one characteristic to match a predetermined and learned tampering event characteristic. 
       FIG. 7  depicts an example operation  400  of the electronic lock  100 . The operation  400  depicts the creation of the normal use profile. At step  402 , the electronic lock  100  stores historic keypad input events. As mentioned above, the historic keypad input events can be stored in the memory  138  and/or remote from the electronic lock  100 , such as on the mobile device  208  or the distributed system  206 . 
     At step  404 , the historic keypad input events are analyzed. In some examples, the processor  136  of the processing unit  116  analyzes the historic keypad input data for trends. In some examples, the processing unit  116  utilizes a mathematical function to analyze the characteristics of the historic keypad input events. In some examples, the processing unit  116  analyzes the data by utilizing a mean, median, mode, or other similar mathematical function to analyze the trends in the historic keypad inputs. Other analyses can be utilized as well. 
     At step  406 , the normal use profile is generated by the processing unit  116 . As noted above, the normal use profile can include information indicating how the electronic lock  100  is normally interacted with. The normal use profile can vary widely based on the where the electronic lock  100  is installed. For example, the normal use profile of a single individual where the electronic lock is installed on a non-main entry door will likely be much different from the normal use profile of a family where the electronic lock is installed on a main entry door. 
     At step  408 , the processing unit  116  receives a keypad input event at the keypad  120  and, at step  410 , a comparison is made between the keypad input event received at the keypad  120  and the normal use profile. 
       FIG. 8  shows the keypad  120  including the touch interface  128  displaying a plurality of characters  126 . In the depicted example, the keypad  120  is a ten-digit numeric keypad with a confirmation key  144  and a lock key  146 . Each character  126  corresponds to a number (i.e., a button) on the keypad  120 . As shown, the four characters  126  are encircled. The encircled characters indicate valid input locations  127  that correspond to a valid access code of “1590.” This means that the user  202  must interact with the “1” character, followed by the “5” character, followed by the “9” character, followed by the “0” character. The valid input locations  127  indicate input locations from the user  202  on the touch interface  128  of the keypad  120 . The processing unit  116  can store this order of valid input locations and can compare any input location on the keypad  120  to the valid input locations. In some examples, an inaccurate input location compared to the valid input location can indicate the existence of a tampering event. 
       FIG. 9  depicts an example keypad input event. Specifically,  FIG. 9  shows a keypad input event when the user  202  first interacts with the keypad  120 , prior to any other input. As noted with respect to  FIG. 8 , the valid access code is “1590”, so the first valid input location  127  should be the character “1.” However, an input location  148  on keypad  120  is shown to be around character “2.” Further, a secondary input location  150  on the keypad  120  is shown to be around character “4.” Character “2” and character “4” both are positioned immediately adjacent the valid input location  127  of character “1.” In some examples, the keypad input events created by each input location  148 ,  150 , immediately adjacent the valid character “1,” are considered normal keypad input events by the processing unit  116  of the electronic lock  100 . Therefore, the processing unit  116  would not indicate a tampering event if it received keypad input events having the input locations  148 ,  150  when the valid input location is “1.” In some examples, contact with immediately adjacent characters  126  to the valid character  126  is permitted as the user can commonly miss-contact the keypad  120  under normal permitted usage, thus such use would not indicate tampering. In some examples, the processing unit  116  can be preprogrammed to not indicate a tampering event if an input location is immediately adjacent a valid input location. However, in some examples, if a keypad input event occurs with an input location that is not immediately adjacent the valid input location, the processing unit  116  can indicate the existence of a tampering event. For example, if an input location on the character “5” or “7” was received as a keypad input event, the processing unit  116  would indicate the existence of a tampering event and, in some examples, trigger the tamper alarm  204 . 
     In some examples, the processing unit  116 &#39;s sensitivity to the input location characteristic of a keypad input event can be customized by the user  202 . In some examples, the processing unit  116  can be programmed to be less sensitive, thereby permitting less accurate input locations from the valid input location without indicating a tampering event. In other examples, the processing unit  116  can be programmed to be more sensitive, thereby indicating the existence of a tampering event when a keypad input event occurs with an input location that is any input location but the valid input location. 
     As described above, a timestamp characteristic can be associated with each keypad input event, specifically the input location. The timestamp can correspond with when the user  202  makes contact with the keypad  120 . In some examples, the processing unit  116  can be programmed to indicate the existence of a tampering event if the keypad input event includes a particular timestamp. In some examples, the processing unit  116  can be programmed to indicate the existence of a tampering event if the keypad input event includes a timestamp that indicates a keypad input event occurs during the night. In some examples, the processing unit  116  can be programmed to indicate the existence of a tampering event if the keypad input event includes a timestamp that indicates a keypad input event occurs during the day (e.g., when the user is away from the electronic lock at work). 
       FIG. 10  depicts an input location  152  around the character “5.” In some examples, extended contact with the touch interface  128  of the keypad  120 , regardless of input location, can be indicative of a tampering event. For example, a user may attempt to drill out, pry open, or otherwise damage the keypad  120  to compromise the electronic lock  100  to gain access through the door  102 . In the depicted example, the input duration around character “5” is a time that is indicative of a tampering event. In some examples, the processing unit  116  can be preprogrammed to indicate the existence of a tampering event if an input duration exceeds two seconds. In some examples, the processing unit  116  can be preprogrammed to indicate the existence of a tampering event if an input duration exceeds three seconds. In some examples, the processing unit  116  can be preprogrammed to indicate the existence of a tampering event if an input duration exceeds four seconds. In some examples, the processing unit  116  can be preprogrammed to indicate the existence of a tampering event if an input duration exceeds five seconds. In some examples, the processing unit  116  can create a normal input duration in the normal use profile based on historic keypad input events. 
     In addition to the above keypad input events, or events occurring on the keypad, in example embodiments, other types of input events may be detectable as tampering events. For example, in some embodiments, an electrical continuity sensor may be included in the exterior assembly  110 , which is broken in the event of an electrical discontinuity detected in the exterior assembly  110 . For example, such an electrical discontinuity may occur in response to an exterior escutcheon being removed, or a circuit board within the exterior circuitry  117  being drilled into or broken. In such instances, a signal may be sent, or detected, via electrical cable  115 , causing the processor  136  to detect a tampering event. 
     Referring now to  FIGS. 11-12 , further example embodiments of an electronic lock are depicted which are configurable to detect tampering events. 
       FIG. 11  shows an example electronic lock  500  according to a further embodiment of the disclosure. In the example shown, the electronic lock  500  includes an exterior assembly  502 , a latch assembly  504 , and an interior assembly  506 . Typically, the exterior assembly  502  is mounted on the outside of a door, while the interior assembly  506  is mounted inside a door. 
     Generally, the example electronic lock  500  lacks an exterior keypad, as seen in electronic lock  100 . However, the electronic lock  500  will generally include the exterior assembly  502  which may detect tampering events. In the example shown, the exterior assembly  502  is in the form of a deadbolt. As discussed above, however, this disclosure is not intended to be limited to only an electronic deadbolt, but encompasses any kind of electronic lock. As shown, the exterior assembly  502  includes a cylinder guard cover  508  that houses internal components of the exterior assembly  502 . In the example shown, the cylinder guard cover  508  has a decorative shape with a rear portion  510  that would be adjacent a door (not shown) and a front portion  512  extending from the door. In this example, the cylinder guard cover  508  has a tapered shape from the rear portion  510  to the front portion  512 , but the exterior assembly  502  and cylinder guard  508  could have a wide variety of different sizes and shapes depending on the particular circumstances. 
     In the embodiment shown, the front portion  512  of the exterior assembly  502  includes a front cover  514  that surrounds a mechanical lock assembly  516 . A mechanical key (not shown) may be inserted into the mechanical lock assembly  516  to mechanically unlock the electronic lock  500 . 
     In the embodiment shown, a light communication device  518  surrounds the front cover  514 . In this example, the light communication device  518  is formed in the shape of a ring surrounding the front cover  514  and mechanical lock assembly  516 . However, the light communication device  518  could be formed in other shapes or positioned differently on the exterior assembly  502 . 
     In some embodiments, the electronic lock  500  may be touch activated. For example, the electronic lock  500  may use capacitive sensing to determine whether the user wants to actuate the electronic lock  500 . The touch surface for capacitive sensing to actuate the electronic lock  500  could be any external surface, including but not limited to, a cylinder guard cover, cylinder guard, keyway, handle, rose, or other exterior surface of the electronic lock  500 . In the example shown, the exterior assembly  502  uses capacitive sensing to determine when a user touches the cylinder guard cover  508 . Accordingly, in the embodiment shown, the user is able to touch anywhere on the cylinder guard cover  508  to lock or unlock the lock assembly  500 , or otherwise activate various functions of the electronic lock  500 . 
     In the example shown, the exterior lock assembly  502  has a torque blade  520  extending from the rear portion  510 . The torque blade extends through an adaptor  522  in the embodiment shown, which is received within a bore in a door to which the electronic lock  500  is being installed or mounted. 
     The latch assembly  504  is disposed in a core in a door and may be actuated manually by the mechanical lock assembly  516 , or electronically by touching anywhere on the cylinder guard cover  508  (in the embodiment shown) to extend/retract a bolt  524 . The bolt  524  moves linearly in and out of a sleeve  526 . When the bolt  524  is retracted, an end of the bolt  524  is generally flush with a base plate  528 . When the bolt  524  is extended, the bolt  524  protrudes through an edge bore in the door into an opening  530  of a strike plate  532 , which is positioned in a jamb adjacent the door. As is typical, the strike plate  532  is attached to the jamb using fasteners  534 . Likewise, fasteners  536  attach the base plate  528  of the latch assembly  504  to a door. 
     In the embodiment shown, the latch assembly  504  includes a spindle  538  that is drivable in a first direction to extend the bolt  524  and a second direction to retract the bolt  524 . The spindle  538  is configured to receive the torque blade  520  such that rotation of the torque blade  520  in a first direction retracts the bolt  524 ; whereas, rotation of the torque blade  520  in the opposite direction causes the spindle to retract the bolt  524 . 
     The torque blade  520  extends through the latch assembly  504  into an opening  540  in a mounting plate  542 , which is attached to an interior side of a door. The torque blade  520  passes through the opening  540  and is received by a spindle driver  544 . The spindle driver  544  provides electronic control of the bolt  524 , such as using a motor to rotate the spindle driver  544  in either a first direction or in a second direction. Since the torque blade  520  is disposed within the spindle  538 , rotation of the spindle driver  544  may be used to extend and/or retract the bolt  524  of the latch assembly  504 . In the embodiment shown, fasteners  546  extend through holes  548  in the mounting plate, which are aligned with openings  550  in the latch assembly  504 . A wiring harness (not shown) electrically connects electronics between the exterior assembly  502  and the interior assembly  506 . Example electronic components included within the exterior assembly  502  and the interior assembly  506  generally can include those as described above in conjunction with  FIG. 5 , except that in this embodiment, keypad  120  may optionally be excluded, and a capacitive touch sensor or other continuity sensor may be included within exterior circuitry  117 . Accordingly, in various embodiments, the keypad  120 , or a capacitive touch sensor, or a continuity sensor associated with or included within an exterior assembly  502  of an electronic lock, may be referred to herein as a tamper sensing device. 
     Additional details regarding such a further alternative electronic lock into which a tamper alarm may be integrated are provided in U.S. Pat. No. 9,024,759, entitled “WIRELESS LOCKSET WITH INTEGRATED ANTENNA, TOUCH ACTIVATION, AND LIGHT COMMUNICATION METHOD”, the disclosure of which is hereby incorporated by reference in its entirety. 
     Referring to  FIG. 12 , a method  600  is shown for detecting a tampering event using any of a variety of electronic locks, including those shown in aspects of the present disclosure. 
     In general, at  602 , the method  600  includes capturing a sensed potential tamper event. The sensed potential tamper event can be any of a variety of types of events as discussed above, such as a keypad event, a discontinuity event, a disassembly event (e.g., removal or damage of an escutcheon), or other types of events experienced by an exterior assembly of the electronic lock. 
     In the example shown, at  604 , an event characteristic is analyzed. In some instances, such as in the case of experiencing a drilling occurrence or other electrical discontinuity, the event characteristic may by definition correspond to a tamper event. In other cases, such as a wrong key code being pressed on a keypad, or other types of mis-typed codes (e.g., in terms of which sequence is selected and in what duration), a tamper event may be detected by comparison to a normal usage characteristic. Accordingly, the specific input event or input type (e.g., drilling, prying, or other damage attempt causing discontinuity, or alternatively, a duration, location, or timestamp of input from a keypad) can correspond to a tampering event according to a particular characteristic of an input event defined as being a tampering event. 
     At operation  606 , depending on the type of potential tamper event and optionally how that event compares to either normal operation or to known tamper events, a tamper alarm may be triggered (at  608 ) or a secondary action (at  610 ) may be taken, analogous to those actions as discussed above in connection with  FIG. 6 . 
     The various embodiments described above are provided by way of illustration only and should not be construed to limit the claims attached hereto. Those skilled in the art will readily recognize various modifications and changes that may be made without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the following claims.