Abstract:
Readers are associated with a number of access credentials and, once authenticated by the reader, may grant the holder of the access credential access to a secured asset. Readers may become the target of attack, such as when an unauthorized party attempts to gain access to the interior of the reader or removes the reader from an installed location. Once removed the reader may be reinstalled in another location or a counterfeit reader used in its place. By providing a paired tamper credential, the reader may deny otherwise authorized access to the secured asset if the tamper credential fails to respond appropriately. The tamper credential may fail to respond due to distance, such as when the reader alone is relocated, or the tamper credential is damaged, such as during an attempt to gain access the interior of the reader and/or remove the reader from its installed location.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a national stage application under 35 U.S.C. 371 of PCT Application No. PCT/IB2014/001190 having an international filing date of Mar. 14, 2014, which designated the United States, which PCT application claimed the benefit of U.S. Application Ser. No. 61/792,432, filed Mar. 15, 2013, both of which are incorporated by reference in their entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure is generally directed toward radio frequency identification (RFID) tamper tags. 
     BACKGROUND 
     RF Identification (RFID) is currently the dominate technology in physical access control systems. Consequently, there is a huge global legacy of installed access control readers that use RFID. 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. 
     Generally, a RFID reader (or simply, a “reader”) is presented with an access credential. The reader then authenticates the access credential, alone or with additional user input (e.g., password, PIN, biometric data, etc.). If successfully authenticated, the reader causes a signal to be sent to an access controller, such as to a door lock, and thereby allow the access credential holder to gain access to a secured asset protected by the access controller, such as a room, building, equipment, etc. 
     Readers and access credentials are subject to a variety of attacks. Attacks may be as crude as physically attacking in an attempt to damage or open the reader, or more sophisticated attacks, such as whereby signals are created in an attempt to mimic the signal of an authenticated access credential. 
     Often readers in a single installation may appear very similar, or even identical, in outward appearance. A bad actor may attempt to remove a legitimate reader. The interior of the legitimate reader may be altered or replaced in an attempt to gain knowledge associated with presented access credentials. In certain environments a bad actor may have legitimate access privileges to one area but not to another. The bad actor may attempt to switch the readers in an attempt to gain access to the unauthorized area. If the physical appearance of the readers is sufficiently similar, personnel may be unaware that the readers have been swapped. 
     SUMMARY 
     It is with respect to the above issues and other problems that the embodiments presented herein were contemplated. 
     Tamper credentials may be embodied as an adhesive tag, such as Mifare, iClass, or physically unclonable function (“PUF”) tags. Other form factors such as cards, key fobs, etc. which also include a tamper mechanism. In certain embodiments disclosed herein, a tamper credential is paired with a reader. Removing or damaging (e.g., partial removal) the tamper credential may indicate via sight, sound, or smell, the tampering via a mechanical and/or chemical indicator. In addition, the reader and tamper credential may maintain a normal state of operation when each is able to perform their portion of a tamper authentication protocol. Damage to the reader or tamper credential, or separation thereof, would then cause the tamper authentication to fail and cause at least the reader to switch to a tamper state. A bad actor attempting to restart the tamper authentication protocol, such as by bringing the separated reader and tamper credential back into proximity with each other, or by providing a replacement tamper credential, would be unable to restart the tamper authentication protocol without the intervention of authorized personnel and/or equipment. 
     In one embodiment, a system is disclosed, comprising: a reader; a tamper credential; a first communication interface comprising transmission and reception components of the reader and the tamper credential that facilitates communication between the reader and the tamper credential, wherein the tamper credential is paired to the reader at least by having an indicia of the tamper credential maintained in a memory of the reader, the reader and tamper credential being operable to communicate when the reader and tamper credential are within a predetermined distance of one another; a processor operable to place the reader in a tamper state upon a failure to communicate with the reader, 
     In another embodiment, a method is disclosed, comprising: operating a reader and a tamper credential in proximity to each other such that, once the reader is powered, each of the reader and tamper credential are operable to communicate with the other; powering the reader; upon powering the reader, cause the reader to transmit a first signal to the tamper credential, the first signal comprising at least a transmitted indicia of the reader; and operating the reader in a tamper state upon the failure of at least one of a number of steps in a tamper authentication protocol, the tamper authentication protocol comprising: receiving the first signal by the tamper credential; accessing, by the tamper credential, an indicia of the reader maintained in a memory of the tamper credential; determining, by the tamper credential, the first signal includes the transmitted indicia of the reader in accord with the indicia of the reader maintained in the memory of the tamper credential; transmitting, by the tamper credential, a second signal to the reader, the second signal comprising at least a transmitted indicia of the tamper credential; upon receiving the second signal, processing, accessing a stored indicia of the tamper credential maintained in a memory of the reader; and determining, by the reader, the second signal includes the transmitted indicia of the tamper credential in accord with the indicia of the tamper credential maintained in the memory. 
     In still another embodiment, an apparatus is disclosed, comprising: a processor; a memory; a first transmitter; a first receiver; and wherein the memory includes an indicia of a tamper credential maintained in the memory; wherein the processor is operable to cause the first transmitter to transmit a first signal; wherein the receiver is operable to receive a second signal; wherein the processor is operable to determine whether the received second signal comprises a received indicia of a tamper credential in accord with the indicia of the tamper credential maintained in the memory; and wherein the processor is configured to operate the apparatus in a tampered state upon at least one of the failure of the first receiver to receive the second signal upon the first transmitter transmitting the first signal and upon the processor failing to determine the received second signal includes the received indicia of the tamper credential in accord with the indicia of the tamper credential maintained in the memory. 
     The phrases “at least one,” “one or more,” and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. 
     The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising,” “including,” and “having” can be used interchangeably. 
     The term “automatic” and variations thereof, as used herein, refers to any process or operation done without material human input when the process or operation is performed. However, a process or operation can be automatic, even though performance of the process or operation uses material or immaterial human input, if the input is received before performance of the process or operation. Human input is deemed to be material if such input influences how the process or operation will be performed. Human input that consents to the performance of the process or operation is not deemed to be “material.” 
     The term “computer-readable medium” as used herein refers to any tangible storage that participates in providing instructions to a processor for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, NVRAM, or magnetic or optical disks. Volatile media includes dynamic memory, such as main memory. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, magneto-optical medium, a CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, a solid state medium like a memory card, any other memory chip or cartridge, or any other medium from which a computer can read. When the computer-readable media is configured as a database, it is to be understood that the database may be any type of database, such as relational, hierarchical, object-oriented, and/or the like. Accordingly, the disclosure is considered to include a tangible storage medium and prior art-recognized equivalents and successor media, in which the software implementations of the present disclosure are stored. 
     The terms “determine,” “calculate,” and “compute,” and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation or technique. 
     The term “module” as used herein refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and software that is capable of performing the functionality associated with that element. Also, while the disclosure is described in terms of exemplary embodiments, it should be appreciated that other aspects of the disclosure can be separately claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is described in conjunction with the appended figures: 
         FIG. 1  depicts a system for controlling access to an asset in accordance with embodiments of the present disclosure; 
         FIG. 2  illustrates a tamper credential being physically attached to a reader in accordance with embodiments of the present disclosure; 
         FIG. 3  illustrates provisioning system whereby a tamper credential is provided with a provisioning payload to provision a reader in accordance with embodiments of the present disclosure; 
         FIG. 4  illustrates a provisioning system whereby a tamper credential provisions a reader in accordance with embodiments of the present disclosure; 
         FIG. 5  illustrates a process for provisioning a reader in accordance with embodiments of the present disclosure in accordance with embodiments of the present disclosure; 
         FIG. 6  illustrates a process for operating a reader in accordance with embodiments of the present disclosure in accordance with embodiments of the present disclosure; and 
         FIG. 7  illustrates a process for operating a reader in accordance with embodiments of the present disclosure in accordance with embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The ensuing description provides embodiments only, and is not intended to limit the scope, applicability, or configuration of the claims. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing the 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 appended claims. 
     The identification in the description of element numbers without a subelement identifier, when a subelement identifiers exist in the figures, when used in the plural, is intended to reference any two or more elements with a like element number. A similar usage in the singular, is intended to reference any one of the elements with the like element number. Any explicit usage to the contrary or further qualification shall take precedence. 
     The exemplary systems and methods of this disclosure will also be described in relation to analysis software, modules, and associated analysis hardware. However, to avoid unnecessarily obscuring the present disclosure, the following description omits well-known structures, components and devices that may be shown in block diagram form, and are well known, or are otherwise summarized. 
     For purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present disclosure. It should be appreciated, however, that the present disclosure may be practiced in a variety of ways beyond the specific details set forth herein. 
     With reference now to  FIG. 1 , system  100  will be described for controlling access to an asset in accordance with embodiments of the present disclosure. In one embodiment, person  102  having access credential  104 , presents access credential  104  to reader  106  whereby data is exchanged via communication interface  112 . Reader  106  determines, alone or in conjunction with other systems (not shown), if access credential  104  is authorized to access secure asset, such as an area controlled by door  110 . Reader  106  validates itself, in part, by exchanging data via communication  108 , with tamper credential  108 . 
     Access credential  104 , communication interface  112 , and portions of reader  106  may be variously embodied such as to facilitate communication interface  112  via contact and/or non-contact means. Non-contact means of operating communication interface  112  include, without limitation, optical (e.g., portions of the visible and invisible electromagnetic spectrum), audible, and RF communications (e.g., using 125 KHz or 13.56 MHz bands, UHF bands, etc.). You should note that the communication interface  112  may also be Bluetooth, BLE, ZigBee, WiFi (through a separate router), etc. Contact means may incorporate magnetic card reader, biometric readers, keypads, or other devices as may be known in the art. Communication interface  114  may be embodied in a form such as to reduce interference with communication interface  112  or other operation of reader  106 . In one embodiment, communication interface  112  may performed via conductors, such as fine wires, structures, or other conductive paths which may be calculated to become inoperable if subjected to tampering. The interfaces  112 ,  114  may also be operated at different non-interfering frequencies. 
     Reader  106  and tamper credential  108  provide an additional authentication procedure whereby the absence of a signal from one may cause the other to operate in or switch to a tamper state. In a further embodiment, reader  106  and tamper credential  108  are paired such that the absence of a unique one may cause the unique other to operate in a tamper state. Tamper credential  108  may deemed absent if it is unable to do any one or more of: receive a signal from reader  106 , authenticate the signal, formulate a reply signal, send the reply signal back to reader  106 , and have the reply signal authenticated. Tamper credential  108  may be unable to perform such operations if move outside of the operational distance of communication interface  114  or if damaged. 
     In another embodiment, reader  106  may be paired with a plurality of tamper credentials  108 , whereby the absence of a signal from any one of the tamper credentials  108  causes the processor to operate in a tamper state. As a benefit, reader  106  may be made more secure. For example, one tamper credential  108  may be placed on the internal housing of reader  106 , such as a seam or weakened area. An attempt to open the housing of reader  106  may then damage one internal tamper credential  108  to render it inoperable and thus cause the processor to be in a tamper state. Reader  106  may be mounted on the insecure side of a wall and a bad actor may simply try to remove reader  106  in its entirety. Doing so may then make a second tamper credential  108  absent to reader  106 . In one embodiment, tamper credential  108  is mounted on the secure side of a wall but in communication interface  114  with reader  106 , such as when the wall is of a structure and/or material to permit communication interface  114  (e.g., RF). As a result of having two tamper credentials  108  paired to reader  106 , additional tamper protection may be provided. As can be appreciated, the addition of more tamper credentials  108  may be provided to further enhance tamper protection, such as on a plurality of the interior, exterior, wired, wireless, embedded within a mounting surface, or other configurations. 
     Placing reader  106  and/or tamper credential  108  in a tamper state may occur within a single failure of one to communicate with the other. In another embodiment, a certain number of failures are permitted before the tamper state is set. For example, lightening or other electromagnetic discharges may cause a brief failure of communication interface  114 . However, if communication interface  114  is restored, and otherwise authenticated, reader  106  and/or tamper credential  108  may continue to operate in a normal state. 
     Operating reader  106  in a tamper state is variously embodied. In one embodiment, tamper state disables reader  106  whereby reader  106  is “bricked” and entirely inoperable. In another embodiment, certain features of reader  106  are enabled or disabled. For example, tamper state may cause reader  106  to send an alarm signal (e.g., reporting signal, visual alarm, audible alarm, etc.). In another example, certain personnel, such as those associated with a different category of access credentials  104 , may still be authenticated by reader  106 . For example, reader  106  that is operating in a tamper state may deny workers (i.e., individuals with normal work duties associated with having access to a secured asset controlled by reader  106 ) access to a secure asset, but allow security personnel to be granted access. In yet another embodiment, tamper state may operate a silent alarm function, whereby reader  106  may authenticates access credentials  104  normally, allow access which would normally be denied, deny accesses, perform no apparent action, or other function, however, reader  106  may issue a reporting signals to notify systems and/or personnel, such as may enable catching a bad actor “red handed.” 
     With reference now to  FIG. 2 , a tamper credential  108  in accordance with embodiments of the present disclosure will be described. Tamper credential may be physically attached to reader  106 . In one embodiment, such as, that illustrated by  FIG. 2 , tamper credential  108  is attached to exterior of reader  106 . In such an embodiment, a bad actor may attempt to replace the internal components of reader  106  but be thwarted as the pairing associated with reader  106  and tamper credential  108  would no longer agree. 
     In other embodiments, the physical structure and/or placement of tamper credential  108  is calculated to disable tamper credential  108  upon an unauthorized access of reader  106 . In one embodiment, tamper credential  108  is placed on a seam or weakened area in or on the housing of reader  106 . In such an embodiment, an attempt gain access to the interior of reader  106  is calculated to cause damage, and thereby disable, tamper credential  108 . In another embodiment, tamper credential  108  may be placed over a screw, locking tab, or other structural joint calculated to require the removal and/or damage and subsequent disabling of tamper credential  108  to open the structural joint. 
     In yet another embodiment, reader  106  may be mounted to a surface (e.g., portion of a wall, post, cabinet, door, etc.) directly, or via mounting hardware, in a manner design to resist unauthorized removal therefrom. The placement and/or design of tamper credential  108  being selected to cause tamper credential  108  to be disabled upon being subject to a tampering event, such as the removal or partial removal of reader  106  from the surface, or removal of the mounting frame from the surface. 
     With reference now to  FIG. 3 , provisioning system  300  will be described in accordance with embodiments of the present disclosure. In certain embodiments described herein, reader  106  receives power from a power supply (e.g., wall outlet, photovoltaic cells, charged batteries, etc.) and once installed, provides power to tamper credential  108 , such as via an inductive loop, conductive wires, or other means. In certain stages of manufacturing of reader  106  and tamper credential  108 , such as once packaged, reader  106  is inoperable as it lacks a suitable power supply. However, tamper credential  108  may incorporate an inductive loop whereby a signal, which readily passes through most packing materials, may be applied to power tamper credential  108 . As a benefit, tamper credential  108  may be provisioned (e.g., loaded with data and/or instructions so as to enable operations) at nearly any point after manufacture, including after packaging. As a further benefit, tamper credential  108  may be provisioned at nearly any point prior to installation at a site without requiring unpacking. 
     In another embodiment, reader  106  incorporates disabled antenna  302 A. Disabled antenna  302 A may be an otherwise operational antenna except for lacking a connection to a suitable power supply. Disabled antenna  302  may be disabled for other reasons, such as when reader  106  has not completed the manufacturing process. However, as tamper credential  108  and reader  106  are, or will become, paired, certain efficiencies may be realized by packaging both the reader  106  and tamper credential  108  within the same packaging. Furthermore, as described with respect to certain embodiments herein, tamper credential  108  may be manufactured within or physically attached to reader  106 . 
     In a further embodiment, reader  106  is packaged with tamper credential  108 . Disabled antenna  302 A is inoperable. Credential antenna  304  is operable if provided a suitable signal. Computer  306  accesses stored providing data in provisioning database  310 , such as to include encryption methodologies, serial numbers, public and/or private keys, customer configuration data, pairing data, and/or other data to provision reader  106  and/or tamper credential  108 . Computer  306  causes antenna  308  to communicate  312  with tamper credential  108  via antenna  304 , and thereby provision tamper credential  108 . In another embodiment, provisioning payload  314  may be associated with provisioning reader  106 . Accordingly, computer  306  may deliver provisioning payload  314  via antenna  308  and communicate  312  with tamper credential  108  via antenna  304 . Once loaded to tamper credential  108 , payload  314  may be stored, modified (e.g., decrypted/encrypted, an indicia of tamper credential  108  added), or otherwise made ready to provision reader  106 . 
     With reference now to  FIG. 4 , provisioning system  400  will be described in accordance with embodiments of the present disclosure. In one embodiment, reader  106  has been installed, or is otherwise powered, enabled antenna  302 B is operational and able to transmit and receive signals. 
     In one embodiment, reader  106  is powered up for the first time since being installed and is in a non-provisioned state. The non-provisioned state may be complete, whereby reader  106  is unable to authenticate any access credential, such as access credential  104 . However, the non-provisioned state may be partial, such as when reader  106  contains certain data enabling operation but lacks other data, such as pairing data whereby reader  106  is paired with tamper credential  108 . 
     In one embodiment, reader  106  and temper credential  108  communicate to provision reader  106 . Reader  106 , having a processor and memory accessible to the processor, signals tamper credential  108 . The signal may be an explicit request for provisioning payload  314  or implied (e.g., a first signal from reader  106  received by tamper credential  108 ). In one embodiment, a processor associated with tamper credential  108  provisions reader  106  with information extracted from provisioning payload  314 . In another embodiment, tamper credential  108  delivers provisioning credential  314  to reader  106 , whereby a processor associated with reader  106  provisions itself. 
     While certain embodiments herein describe transmitting provisioning payload  314 , it should be noted that various operations may be performed on provisioning payload  314  or portions thereof, such as to ensure validity of the content, the source, and/or the destination, without departing from the teachings provided herein. For example provisioning payload  314  may be modified by tamper credential  108  to include other data, such as an encrypted data element, which may alone or in combination with additional data exchanges, may be used to determine the authenticity of provisioning payload  314 . Once provisioned, reader  106  may operate normally. 
     It should be noted that legitimate removal of reader  106  and/or tamper credentials  108  may be required. Additionally, reader  106  and/or tamper credential  108  may become disabled by an act other than tampering (e.g., accidental damaged caused by a forklift, workers erroneously remove one or more of the reader  106  and/or tamper credential  108 , etc.). To place the reader  106  and tamper credential  108  back into service, re-pairing may be required. Authorized device  402  may re-pair reader  106  and tamper credential  108 , such as by utilizing a secondary access, such as an administrator access, physical port, remote server, and/or other authorized means. 
     With reference now to  FIG. 5 , process  500  will be described for provisioning a reader in accordance with embodiments of the present disclosure. In one embodiment, step  502  formats a provisioning payload, such as provision payload  314 . Step  502  may be performed in conjunction with the manufacturing of the reader, such as reader  106 , or during installation or other operation prior to being put into service. Step  502  may be performed with data retrieve from provisioning database  310  and delivered by computer  306 . 
     Step  504  delivers the provisioning payload to tamper credential  504 . Step  506  receives an initialization signal from the reader. Step  508  provisions the reader. Process  500  may terminate at this point, such as when a single attempt to provision the reader is all that is desired. However, any failure may warrant a repeated attempt. Therefore, step  510  may determine if the provisioning steps were successful. If yes, optionally step  512  may remove the provisioning payload from the tamper credential and process  500  may end. If no, optional step  514  may perform certain error handling operations (e.g., display an error code, signal an operator, “call home” to a computer, etc.). Optional step  516  may determine if a retry should be performed, if yes processing may continue at step  508  or other step as may be determined as a matter of design choice. If no, processing may continue to optional step  518 , such as to notify the operator that the installation failed or other operation. 
     Provisioning reader  106  with provisioning payload  314  stored on tamper credential  106  may be variously embodied. In one embodiment, provisioning payload includes specific data to enable operation of reader  106 . For example, the access credentials that will or will be granted access to the asset protected by reader  106 . In another embodiment, provisioning payload  314  includes pairing information associated with tamper credential  108 , or a plurality thereof and other information to enable communication interface  114 . In such an embodiment, additional provisioning information (e.g., identity of the specific access credentials that will or will not be granted access) may be provided at a different time. 
     With reference now to  FIG. 6 , process  600  will be described for operating a reader in accordance with embodiments of the present disclosure. In one embodiment, step  602  receives an access credential. Step  602  may be the result of a person placing an access credential within an operational range of the reader, such as reader  106 . In other embodiments, step  602  is the result of an access credential with a magnetic strip being swiped on a reader associated with reader  106 . In another embodiment, step  602  is the result of personal information (e.g., PIN, password, code, biometric data, etc.) being provided to an associated input device of reader  106 . In additional embodiments, two or more of the foregoing may be implemented in step  602 . 
     Step  604  determines if the processor is operating in a tamper state. If step  604  is affirmative, optional step  610  may be performed, such as to create an alarm signal to notify other personnel and/or systems, display the tamper state (e.g., light, marquee message, on-board alarm), or other notification means. Step  612  then denies access to the credential holder associated with presenting the credential in step  602 . 
     If step  604  is false, processing may then continue to step  606  where the credential presented is determined to be authorized or not authorized. If authorized, access may then be granted by step  608  or denied by step  612  if not authorized. 
     As with other processes described herein, certain additions, deletions, and modifications may be made without departing from the teachings provided. For example, and as described above, the processor when operating in a tamper state may disable reading operations, such as to cause step  602  and/or other steps to be inoperable. 
     With reference now to  FIG. 7 , process  700  will be described for operating a reader in accordance with embodiments of the present disclosure. In one embodiment, step  702  sets the processor state to normal. In another embodiment, step  702  may set a tamper state to false or other indicator associated with reader, such as reader  106 , being in a non-tamper state. 
     Step  704  sends a first signal from the reader. The intended recipient of the first signal may be a tamper credential, such as tamper credential  108 . Step  706  validates the signal by the tamper credential. The specific methodology employed to validate the first signal may be determined as a matter of design choice. In one embodiment, such as a relatively low security environment, the first signal may simply be a trigger or signal to energize an inductive loop of the tamper credential, such as to cause the tamper credential to respond (such as to perform step  710 ). In such an embodiment, the tamper credential may be limited to determining the presence or absence of a signal and enable only one sided authentication by the reader. In another embodiment, at least some data is provided such that step  706  validates the data of the first signal. The data may be unencrypted, for somewhat more secure implementations, or highly encrypted, for more secure implementations. In still a further embodiment, the delivery of the data within the first signal, performed by step  704 , may incorporate several data exchanges between the reader and tamper credential (e.g., challenge-response, public-private encrypted data exchanges, etc.). 
     Step  708  determines if the first signal is valid and, if yes, step  710  sends a second signal. If step invalid, processing continues to step  716 . Step  712  validates the second signal from the tamper credential. As described above with respect to the first signal, the second signal may be variously embodied and the specific embodiment selected, for example, to provide a desired level of security. In one embodiment, the second signal includes identifying an indicia of the tamper credential (e.g., serial number, etc.) which is known to the reader. An otherwise valid signal, but with a different serial number, may be an indication that a bad actor has attempted to substitute a source of false validation information (e.g., a substitute tamper credential) in an effort to keep the reader operational. Similarly, the tamper credential may include an indicia of the reader such that validation step  706  determines if the expected indicia is provided or if the paired reader has been substituted. The indicia may be an unencrypted serial number, encrypted serial number, identifier, shared secret, or other means by which a specific tamper credential may indicate its identify to the reader and, optionally, vice versa. If valid, step  714 , is yes and may optionally execute step  718  or process  700  may continue back at step  704 . If step  714  is no, processing continues to step  716  whereby a tamper state is set. 
     In another embodiment, the absence of the first signal would cause step  708  to be determined in the negative and the absence of the second signal would similarly cause step  714  to answer in the negative. 
     Step  718  may be omitted as a matter of design choice. Certain advantages may be provided by implementing a certain delay, such as to reduce power and/or processing requirements. Step  718  may further implement a “heartbeat” exchange during the delay. For example, steps  704  through  712  may exchange highly encrypted and/or obfuscated data and if successful, step  718  may implement a five second delay and during that delay, exchange a simplified signal once every second. Any disruption in the simplified display may cause step  718  to terminate early and/or trigger another action, which may also include setting the processor state to be in a tamper state. Assuming the appropriate passage of time and the predetermined delay period has expired, processing then continues at step  704  whereby the highly encrypted and/or obfuscated data exchange is repeated. 
     In addition to setting a processor state to a tamper state, step  716  may be further embodied by setting a processor or memory value or otherwise causing one or more tamper credentials to be place into a tamper state. 
     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. 
     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. 
     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. 
     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. 
     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.