Secret data protection method, secret intelligent device and secret system

Abstract

The application discloses a secret data protection method, and belongs to the technical field of information security. The method is applied to a secret intelligent device storing a key list, periodically sends an ID query instruction through a near field communication module, queries valid IDs of digital labels within a set range nearby, judges whether the received valid IDs exist in the key list, starts system self-locking if the valid IDs do not exist in the key list or the valid IDs are not received within preset return time, and enters a self-destruction mode when a set condition is met, executes a self-destruction countdown in the self-destruction mode, and destroys secret data stored in the secret intelligent device if the valid IDs are not received when the countdown ends. The application also discloses corresponding secret intelligent devices and a secret system. The scheme realizes intelligent protection of secret data by combining a near field communication technology with a self-destruction mechanism, effectively prevents secret data leakage, and improves data security.

Description

Technical Field

[0001] This application relates to a method for data security protection, and more specifically, to a method for confidential data protection based on authentication using near-field communication and digital tags. Background Technology

[0002] With the rapid development of information technology and the continuous improvement of digitalization, secure intelligent devices are increasingly widely used in military, government, and enterprise fields. These devices typically store highly sensitive confidential information, thus placing extremely high demands on their security protection. Traditional secure intelligent devices mainly rely on physical isolation, access control, and encryption technologies to protect data security, but they still face many security risks in actual use.

[0003] For example, if the device is snagged or collided with by a foreign object during operation, resulting in loss, or if the user is unable to move due to force majeure (such as unconsciousness, severe fall injury, or death) and is then stolen by a third party, it will cause unpredictable confidentiality and security incidents.

[0004] These flaws prevent secure smart devices from taking timely and effective data protection measures when lost, stolen, or when the user loses control, potentially leading to serious consequences such as the leakage of confidential information. Summary of the Invention

[0005] To address the problem that existing secure smart devices cannot take timely and effective data protection measures when lost, stolen, or when the user loses control, which may lead to serious consequences such as leakage of confidential information, this application provides a secure data protection method, a secure smart device, and a secure system.

[0006] To achieve the above objectives, this application provides a confidential data protection method applied to a secure smart device, the secure smart device storing a key list, the key list including the authorization ID of at least one authorized digital tag, the method comprising the following steps:

[0007] At preset intervals, an ID query command is sent via the near-field communication module; the ID query command is used to query valid IDs of digital tags within a set range nearby. If a valid ID is received from a digital tag based on the ID query instruction, determine whether the valid ID exists in the key list; If the valid ID does not exist in the key list, or if no valid ID is received within the preset return time, the system self-lock is activated, and when the set conditions are met, it enters self-destruct mode; in the system self-lock state, operation on the confidential data stored in the confidential smart device is prohibited; in the self-destruct mode, a self-destruct countdown is executed, and the self-destruct countdown time is longer than the preset query time; If a valid ID is not received by the end of the self-destruct countdown, the confidential data stored in the secure smart device will be destroyed.

[0008] Preferably, the key list further includes a key corresponding to the authorization ID, and the method further includes: If the valid ID exists in the key list, then the corresponding key is used to log in to the digital tag; After successful login, the system confirms that the secure smart device is located in a preset legal area, generates a new key for the valid ID, sends the new key to the corresponding digital tag, and updates the key list.

[0009] Furthermore, if a valid ID is received during the self-destruct countdown, the self-destruct mode is exited, and the process returns to the step of determining whether the valid ID exists in the key list.

[0010] Optionally, the setting conditions include: after sending the ID query command again through the near-field communication module, no valid ID is received within a preset return time.

[0011] This application also provides a secure smart device, comprising: The intelligent host is used to execute the aforementioned confidential data protection methods; A near-field communication module includes a near-field communication chip and an antenna, wherein the near-field communication chip connects the smart host and the antenna; The self-destruct module is used to destroy the confidential data stored in the secure smart device; The power module supplies power to the intelligent host, near-field communication module, and self-destruct module.

[0012] Preferably, the intelligent host includes a main control chip, a system memory, and a data memory, with the main control chip connected to both the system memory and the data memory. The main control chip is used to control the operation of the secure intelligent device, the system memory is used to store system data, and the data memory is used to store secure data.

[0013] Furthermore, the self-destruct module includes a self-destruct control chip and a boost chip. The self-destruct control chip is connected to the main control chip and the boost chip, and the boost chip is connected to the data memory. The self-destruct control chip is configured to send a boost command to the boost chip when the self-destruct countdown ends, so that the boost chip outputs an abnormally high voltage to the data memory to physically destroy the data memory.

[0014] This application also provides a security system, including the above-mentioned security smart device and at least one digital tag, the digital tag being used to be set at a predetermined location or area.

[0015] Compared with the prior art, this application has the following beneficial effects: By using a near-field communication module to automatically sense the device's location and status, it can promptly determine whether the device has been lost or stolen by a third party. Compared to existing technologies that rely on manual adherence to standardized procedures, this significantly improves the automation and reliability of confidentiality management. By setting a self-destruct mode, when the device is detected to be lost or stolen, it can automatically lock itself and, if necessary, physically destroy confidential data, effectively preventing confidentiality and security incidents. The combination of self-locking and self-destruction hierarchical protection mechanisms provides multi-layered security for confidential data, significantly enhancing security capabilities compared to existing technologies that rely solely on manual management. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Furthermore, these drawings and textual descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to specific embodiments.

[0017] Figure 1 A flowchart illustrating a confidential data protection method provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a secure smart device provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a security system provided in an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0019] Example 1 This embodiment provides a method for protecting confidential data, applied to a secure smart device. The secure smart device stores a key list, which includes the authorization ID of at least one authorized digital tag and a key (generated using a random algorithm) corresponding to each authorization ID. This key list is pre-written into the secure smart device. When the secure smart device starts, the system automatically loads the key list into memory. In some embodiments, the key list is stored in encrypted form, with only the main control chip having decryption privileges, thereby further improving security.

[0020] like Figure 1 As shown, the method includes the following steps: Step S1: Timed ID Query. The secure smart device sends an ID query command via the near-field communication module at preset query intervals. This ID query command is used to query valid IDs of digitized tags within a defined nearby range. The ID query command uses a standard near-field communication protocol (such as ISO / IEC 14443), modulates it into an electromagnetic wave signal, and transmits it through an antenna, covering a defined nearby range (typically 1-10 cm, adjustable according to the actual scenario).

[0021] It should be noted that under normal use, the digital tag is used alone or in conjunction with other devices, placed or set in a specific location or area to facilitate interaction with the security smart device. In this step, after receiving the ID query command, the digital tag reads the pre-stored ID information as a valid ID and returns it to the security smart device via its antenna. However, if the security smart device malfunctions, such as being lost or stolen, and becomes too far from the digital tag (beyond the set range), it will be unable to interact with the digital tag normally.

[0022] The ID query process is performed periodically to verify whether the current location of the secure smart device is abnormal. The preset query time can be set according to actual needs, such as every 30 seconds or every minute, etc.

[0023] If the secure smart device receives a valid ID returned by the digital tag based on the ID query command, it proceeds to step S2. If no valid ID is received within the preset return time (e.g., 2 seconds), it proceeds to step S4.

[0024] Step S2: ID verification.

[0025] In this step, when the secure smart device receives a valid ID, it determines whether the valid ID exists in the key list. If the valid ID exists in the key list, it logs into the digital tag using the corresponding key. The process is as follows: the secure smart device first queries the key list for the key corresponding to the valid ID, and then sends a login command (carrying the key) to the digital tag. After receiving the key, the digital tag compares it with its stored key for verification. If the keys match, it returns a successful login result to the secure smart device, confirming that the secure smart device is located in the preset legal area.

[0026] If a valid ID is not in the key list, it means that the label is unauthorized or a counterfeit label, and the system will directly jump to step S4.

[0027] Step S3: Key update.

[0028] In this step, after successfully logging into the digital tag, the secure smart device generates a new key for the valid ID (i.e., the ID of the successfully logged-in digital tag), sends the new key to the corresponding digital tag, and updates the key list. Upon receiving the update key instruction and the new key, the digital tag stores the new key in its memory, overwriting the original key. This mechanism implements "one-time key," greatly enhancing the system's resistance to replay attacks and eavesdropping, further improving security.

[0029] Step S4: System self-locking triggered.

[0030] In this step, if a valid ID does not exist in the key list, or if a valid ID is not received within the preset return time, the system will initiate a self-locking mechanism. A valid ID not existing in the key list indicates that the corresponding digital tag is an unauthorized tag. Failure to receive a valid ID within the preset return time indicates that normal communication with the digital tag is currently impossible, i.e., an abnormal situation has occurred. For example, this could be due to the loss of the secure smart device, resulting in excessive distance from the digital tag preventing communication; or it could be due to signal interference preventing communication.

[0031] In any of the above scenarios, it indicates that the secure smart device may be malfunctioning and requires system locking to ensure that confidential data is not leaked. While the system is locked, no operations are permitted on the confidential data stored on the secure smart device, including but not limited to reading, copying, and overwriting. In practical implementation, while the system is locked, all access interfaces to confidential data (including USB, network, Bluetooth, etc.) are disabled, with only the near-field communication module remaining for recovery verification.

[0032] In practice, upon the occurrence of the aforementioned anomalies, the system can immediately enter a self-locking state, or a predetermined self-locking countdown can begin, after which the system enters the self-locking state. During the self-locking countdown, if a valid ID is successfully received and exists in the key list, the system immediately exits the self-locking mode and stops the countdown. Thus, the self-locking countdown can eliminate short-term communication interruptions caused by signal interference.

[0033] Step S5: Self-destruct mode activated.

[0034] After entering the system's self-locking state, further judgment is made. When the set conditions are met, the secure smart device enters self-destruct mode. After entering self-destruct mode, a self-destruct countdown is executed. The self-destruct countdown time is longer than the preset query time to ensure that at least one more attempt is made to obtain a valid ID and complete the verification process in step S2.

[0035] In some embodiments, the set conditions include not receiving a valid ID within a preset return time after sending the ID query command again via the near-field communication module.

[0036] In other embodiments, the set conditions include: N consecutive (e.g., N=3) query failures (i.e., no valid ID is received), or query failures within a consecutive T (e.g., T=5 minutes).

[0037] Step S6: Exit self-destruct mode.

[0038] If a valid ID is received during the self-destruct countdown, the system exits self-destruct mode and returns to step S2 to re-perform the verification process. This mechanism prevents accidental destruction due to temporary communication interruptions or brief tag malfunctions.

[0039] Step S7: Data destruction is performed.

[0040] If a valid ID is not received by the end of the self-destruct countdown, it is determined that the secure smart device has malfunctioned (e.g., lost or stolen). To ensure that the data is not leaked, the secure smart device's stored confidential data is destroyed. In practice, this can be achieved by directly destroying the memory storing the confidential data, for example, by providing the memory with an abnormally high voltage (exceeding the memory's maximum allowable voltage) to burn it out.

[0041] This protection method achieves multiple layers of security protection for confidential data through periodic query of authorization tags, dynamic key updates, hierarchical protection mechanisms, and physical destruction measures, ensuring that confidential data will not be illegally obtained in an unauthorized environment.

[0042] Example 2 This embodiment provides a secure smart device for storing secure data, and the secure data can be protected using the method of Embodiment 1.

[0043] like Figure 2 As shown, the secure intelligent device comprises four main components: an intelligent host, a near-field communication module, a self-destruct module, and a power supply module.

[0044] The intelligent host, as the core control unit of the entire device, is responsible for executing the confidential data protection method, and the control logic is the same as that described in Embodiment 1.

[0045] In some embodiments, the intelligent host includes three core components: a main control chip, a system memory, and a data memory. The main control chip is connected to both the system memory and the data memory, forming a complete data processing and storage architecture. The main control chip is responsible for controlling the overall operation of the secure intelligent device, including functions such as instruction processing, data management, communication control, and security monitoring. The system memory is dedicated to storing system data, including critical system information such as the operating system, control programs, and key lists, ensuring the normal operation of the device. The data memory is dedicated to storing confidential data that needs protection; its separate design from the system memory facilitates hierarchical protection and precise data destruction.

[0046] The near-field communication (NFC) module is responsible for wireless communication with external digital tags, and its working principle is the same as the communication process in Embodiment 1. This module includes two key components: a NFC chip and an antenna. The NFC chip, as the core of the communication control, connects the main control chip of the smart host to the antenna, and is responsible for handling communication protocols, signal modulation and demodulation, and data transmission control. The antenna is responsible for transmitting and receiving electromagnetic waves, establishing a communication link with nearby digital tags through electromagnetic induction to achieve functions such as ID query, authentication, and key update. In some embodiments, the NFC chip can be implemented using a radio frequency (RF) chip, allowing the NFC module to perform radio frequency communication with external digital tags.

[0047] The self-destruct module is the last line of defense for device security, used to completely destroy confidential data in an emergency.

[0048] In some embodiments, the self-destruct module includes two core components: a self-destruct control chip and a boost converter chip. The self-destruct control chip connects the main control chip and the boost converter chip, receiving self-destruct commands from the main control chip and controlling the entire self-destruct process. The boost converter chip connects to the data storage device and has the capability to boost the normal operating voltage to an abnormally high voltage (the specific value is set according to actual conditions and needs to exceed the maximum allowable voltage of the data storage device). The self-destruct control chip's working mechanism is specifically configured as follows: upon receiving a self-destruct countdown command from the main control chip, it begins a precise countdown process. At the end of the countdown, the self-destruct control chip immediately sends a boost command to the boost converter chip, driving the boost converter chip to output an abnormally high voltage far exceeding its tolerance range to the data storage device. This voltage surge physically destroys the data storage device's storage units, ensuring that confidential data cannot be recovered.

[0049] The power module provides a stable and reliable power supply for the entire device, powering the intelligent host, near-field communication module, and self-destruct module. Based on the power consumption characteristics and voltage requirements of each module, the power module provides corresponding power management and voltage regulation functions to ensure that each module receives sufficient power support under normal operating conditions and emergency self-destruction conditions.

[0050] This secure intelligent device, through its rationally designed hardware architecture, achieves a complete functional chain encompassing data storage, communication verification, security monitoring, and emergency data destruction. The coordinated operation of each module ensures secure data access under normal authorized conditions and reliable data destruction under abnormal conditions, providing hardware-level security for confidential data.

[0051] Example 3 Based on the above embodiments, this embodiment further provides a security system, such as... Figure 3 As shown, it comprises two main components: a secure smart device and at least one digital tag.

[0052] The secure intelligent device adopts the same hardware architecture and working principle as Embodiment 2, including an intelligent host, a near-field communication module, a self-destruct module, and a power supply module. The intelligent host, as the core control unit, executes the secure data protection method; its internal main control chip, system memory, and data storage have the same structure and function as in Embodiment 2. The near-field communication module is responsible for wireless communication with the digital tag, transmitting and receiving electromagnetic waves through a near-field communication chip and antenna. The self-destruct module, through the coordinated operation of the self-destruct control chip and the boost chip, physically destroys the data storage in an emergency. The power supply module provides a stable power supply to all modules.

[0053] Digital tags, as an authentication component of the system, are set up in predetermined locations or areas for near-field communication authentication with secure smart devices.

[0054] In some embodiments, each digital tag also contains core components such as a main control chip, memory, and antenna. The digital tag's memory pre-stores its unique tag ID and corresponding key as authentication credentials. The digital tag's antenna is responsible for receiving electromagnetic wave signals (such as ID query commands) emitted by the secure smart device, while simultaneously transmitting the tag's identity information back to the secure smart device.

[0055] The security system operates based on the authentication principle of near-field communication (NFC). The main control chip of the security smart device sends ID query commands via the NFC module at preset query intervals to search for digitized tags within a defined range. When a digitized tag receives the query command, its antenna generates current in response to the electromagnetic field, powering its main control chip. After initialization, the main control chip reads the ID information from its memory and transmits the ID (valid ID) back to the security smart device via its antenna.

[0056] Upon receiving a valid ID, the secure smart device checks if it exists in a pre-stored key list. If the valid ID exists, the system uses the corresponding key to verify the identity against the digitized tag. The digitized tag's main control chip, upon receiving the key verification request, reads the key from its internal memory and compares it. If the keys match, a success result is returned, confirming that the secure smart device has been placed in the designated area. Furthermore, after successful verification, the secure smart device generates a new key for the valid ID, sends the new key to the corresponding digitized tag, and updates its local key list to prevent security risks from the original key being leaked. In other words, a new key is generated each time identity verification is successfully performed using the key, thereby further enhancing security. The new key is randomly generated using an algorithm, and the specific generation algorithm can be selected according to actual needs.

[0057] When a valid ID does not exist in the key list, or if no valid ID is received within the preset return time, the secure smart device can immediately (or after a certain delay) activate the system's self-locking mechanism. In the self-locking state, the secure smart device is prohibited from performing any operations on the stored confidential data, including but not limited to reading, copying, and overwriting. Simultaneously, the system further assesses the situation and, if necessary, enters self-destruct mode. In self-destruct mode, the main control chip sends a self-destruct countdown command to the self-destruct control chip. The self-destruct countdown time is set to be longer than the preset query time, providing a buffer for potential network delays or temporary communication interruptions.

[0058] During the self-destruct countdown, the secure smart device continuously monitors for a valid ID. If a valid ID is received during the countdown, the system immediately exits self-destruct mode and re-enters the ID verification process. If no valid ID is received by the end of the self-destruct countdown, the self-destruct control chip sends a boost command to the boost chip. The boost chip outputs an abnormally high voltage to the data memory and physically destroys the memory, ensuring that the confidential data cannot be recovered.

[0059] This security system achieves location- and region-based secure management of confidential data through hardware-level authentication and self-destruct mechanisms. The predetermined deployment of digital tags ensures that secure smart devices can only function properly within authorized areas. Once outside the authorized environment or subjected to unauthorized access, the system automatically activates protective measures, effectively preventing the leakage and misuse of confidential data.

[0060] Preferably, the digital tag is a passive tag, meaning it has no built-in power supply. Instead, it generates an induced current by inducing electromagnetic waves within a certain range through its antenna, thus obtaining operating power. In this application, the electromagnetic waves are generated by the secure smart device. Its internal near-field communication module actively emits electromagnetic waves of a specific frequency (e.g., 13.56MHz) through its antenna. When the antenna (a carefully designed coil) of the digital tag enters this electromagnetic field range, it generates an induced current through the principle of electromagnetic induction. This configuration reduces the complexity and size of the digital tag by using a passive tag design. Furthermore, when the distance between the secure smart device and the digital tag exceeds the electromagnetic induction range (e.g., the secure smart device is stolen or lost), the digital tag will automatically power off and become unable to respond to ID query commands issued by the secure smart device, thereby triggering subsequent protection actions such as system self-locking and data destruction of the secure smart device.

[0061] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0062] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0063] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0064] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0065] Those skilled in the art will understand that all or part of the steps of the methods implementing the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0066] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0068] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for protecting confidential data, characterized in that, Applied to a secure smart device, the secure smart device storing a key list, the key list including the authorization ID of at least one authorized digital tag, the method includes: At preset intervals, an ID query command is sent via the near-field communication module; the ID query command is used to query valid IDs of digital tags within a set range nearby. If a valid ID is received from a digital tag based on the ID query instruction, determine whether the valid ID exists in the key list; If the valid ID does not exist in the key list, or if no valid ID is received within the preset return time, the system self-lock is activated, and when the set conditions are met, it enters self-destruct mode; in the system self-lock state, operation on the confidential data stored in the confidential smart device is prohibited; in the self-destruct mode, a self-destruct countdown is executed, and the self-destruct countdown time is longer than the preset query time; If a valid ID is not received by the end of the self-destruct countdown, the confidential data stored in the secure smart device will be destroyed.

2. The method according to claim 1, characterized in that, The key list also includes keys corresponding to the authorization ID, and the method further includes: If the valid ID exists in the key list, then the corresponding key is used to log in to the digital tag; After successful login, the system confirms that the secure smart device is located in a preset legal area, generates a new key for the valid ID, sends the new key to the corresponding digital tag, and updates the key list.

3. The method according to claim 1, characterized in that, Also includes: If a valid ID is received during the self-destruct countdown, the self-destruct mode is exited, and the process returns to the step of determining whether the valid ID exists in the key list.

4. The method according to claim 1, characterized in that, The setting conditions include: After sending the ID query command again via the near-field communication module, no valid ID was received within the preset return time.

5. A secure intelligent device, characterized in that, include: Intelligent host, used to perform the method as described in any one of claims 1 to 4; A near-field communication module includes a near-field communication chip and an antenna, wherein the near-field communication chip connects the smart host and the antenna; The self-destruct module is used to destroy the confidential data stored in the secure smart device; The power module supplies power to the intelligent host, near-field communication module, and self-destruct module.

6. The secure intelligent device according to claim 5, characterized in that, The intelligent host includes a main control chip, a system memory, and a data memory, with the main control chip connected to the system memory and the data memory respectively. The main control chip is used to control the operation of the secure intelligent device, the system memory is used to store system data, and the data memory is used to store secure data.

7. The secure intelligent device according to claim 6, characterized in that, The self-destruct module includes a self-destruct control chip and a boost chip. The self-destruct control chip is connected to the main control chip and the boost chip, and the boost chip is connected to the data memory. The self-destruct control chip is configured to send a boost command to the boost chip when the self-destruct countdown ends, so that the boost chip outputs an abnormally high voltage to the data memory to physically destroy the data memory.

8. A security system, characterized in that, include: The secure intelligent device as described in any one of claims 5 to 7; At least one digital tag, which is used to be placed in a predetermined location or area.

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