A privacy query method and device for a wireless body area network

Abstract

The application provides a privacy query method and device for a wireless body area network, and relates to the technical field of encrypted communication, and the method comprises the following steps: a trusted authorization center obtains and discloses public parameters by using elliptic curve cryptography; a server arranges a historical word list set according to corresponding key hash values of historical keywords, and completes user registration according to identity information and the trusted authorization center; a target hash value of a target keyword is obtained, and a blinding factor, an encryption parameter, a blinding point and an anonymous signature are generated according to a generated temporary false identity, identity information, a system registration public key and the public parameters, and a data query request is sent to the server; a second random number and the target keyword are used to decrypt a privacy data set fed back by the server, and a privacy query result is obtained, wherein, after the anonymous signature is verified successfully, the server queries the historical word list set according to the target hash value, and obtains a privacy data set according to a query result, thereby effectively improving the privacy query security.

Description

Technical Field

[0001] This invention relates to the field of encrypted communication technology, and more specifically, to a privacy query method and apparatus for wireless body area networks. Background Technology

[0002] Remote medical inquiry services, as a core component of the smart healthcare system, rely on wireless communication and data processing technologies to enable cross-platform retrieval of medical data and remote doctor-patient interaction. This overcomes geographical and time limitations, improves the efficiency of medical resource utilization, and provides patients with convenient health data inquiries and treatment advice. Simultaneously, it assists medical staff in efficiently managing patient health data, representing a significant manifestation of the digital and intelligent development of healthcare services. With the widespread adoption of the Internet of Things (IoT) and Wireless Body Area Networks (WBANs) in smart healthcare systems, remote medical inquiry services have greatly enhanced the efficiency of medical resource utilization.

[0003] Existing remote medical inquiry services mostly rely on wireless body area networks to build data transmission and query systems. Some solutions use pseudonymous certificate mechanisms to protect user privacy, requiring users to pre-store a large number of certificates and corresponding private keys, which puts a significant storage burden on terminal devices. Frequent certificate replacements and continuous expansion of the revocation list increase communication latency and verification overhead, leading to delays in medical queries. Some solutions optimize the authentication process based on group signatures or bilinear pairing technology, but performance bottlenecks are exacerbated when invalid signatures are encountered during group key updates or batch verification, increasing retransmission and communication costs. Other solutions use anonymous credential technology to reduce certificate management overhead, but the complexity of the cryptographic operation process is a problem, which contradicts the limited computing and storage resources of medical terminal devices. At the same time, the authentication parameter design of some solutions is prone to security issues such as signature forgery and replay attacks. Furthermore, the ability to trace identity is not effective in achieving user anonymity, resulting in a contradiction between the need for privacy protection and the need for malicious behavior monitoring. Summary of the Invention

[0004] The problem addressed by this invention is how to balance the needs of privacy protection and regulatory requirements in remote medical inquiries.

[0005] To address the aforementioned issues, this invention provides a privacy query method and apparatus for wireless body area networks.

[0006] In a first aspect, the present invention provides a privacy query method for wireless body area networks, comprising: After system initialization, user registration is completed based on the user's identity information and the trusted authorization center. The system initialization includes the trusted authorization center using elliptic curve cryptography to obtain and publish public parameters, and the server organizing a set of historical word lists based on the key hash values ​​corresponding to historical keywords. Obtain the target hash value of the target keyword, and generate a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters. Generate encryption parameters based on the blinding factor, perform blinding processing based on the generated first random number, second random number, the public parameters, the blinding factor, and the target hash value to obtain a blinding point, perform anonymous encryption processing on the temporary fake identity to obtain an anonymous signature, and send a data query request to the server. The privacy data set returned by the server is decrypted based on the second random number and the target keyword to obtain a privacy query result. The server is used to query the historical word list set based on the target hash value after the anonymous signature is successfully verified, and encrypt the query result using the blinding point and the generated third random number to obtain the privacy data set.

[0007] Optionally, the trusted authorization center uses elliptic curve cryptography to obtain and publish public parameters, including: Using the elliptic curve cryptography described above, the prime order and the corresponding prime field and elliptic curve are obtained based on cryptographic security standards, and the additive cyclic group and generator corresponding to the prime order are generated. The system public key is obtained based on the generator and the system master private key; The common parameters are obtained based on the acquired general hash function and short hash function, as well as the additive cyclic group, the generator, the prime order corresponding to the additive cyclic group, and the system public key; The public parameters are disclosed to the user and the server.

[0008] Optionally, the server compiles a set of historical word lists based on the key hash values ​​corresponding to historical keywords, including: The server public key is obtained based on the randomly generated server private key and the generator; For historical keywords in the database, the short hash function is used to calculate the historical short hash value corresponding to each historical keyword; The historical keywords corresponding to the same historical short hash value are organized into a word list to generate the historical word list set.

[0009] Optionally, the step of completing user registration based on identity information and a trusted authorization center after system initialization includes: Obtain the identity information and send the identity information and registration request to the trusted authorization center; The registration authentication parameters fed back by the trusted authorization center are verified according to the registration verification equation. The trusted authorization center is used to obtain the system registration public key based on the generated registration random number and the generator, generate the registration authentication parameters based on the public parameters, the system registration public key, the identity information and the registration random number, and feed back the system registration public key and the registration authentication parameters to the user. If verification is successful, the user information is obtained, including the identity information, the system registration public key, and the registration authentication parameters; if verification fails, the registration is terminated.

[0010] Optionally, obtaining the target hash value of the target keyword and generating a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters includes: The target hash value of the target keyword is obtained using the short hash function. Using the general hash function, the original hash value is obtained by concatenating the identity information and the system registration public key into an identity string, and a temporary hash value is obtained based on the temporary fake identity; The blinding factor is obtained based on the temporary hash value and the original hash value.

[0011] Optionally, the step of performing blinding processing based on the generated first random number, second random number, the public parameter, the blinding factor, and the target hash value to obtain a blinding point, performing anonymous encryption processing on the temporary false identity to obtain an anonymous signature, and making a data query request to the server includes: The blinding point is obtained based on the second random number, the generator, and the target hash value; The system registration public key and the registration authentication parameters are encrypted using the blinding factor to obtain the encrypted registration public key and encrypted registration parameters. Query parameters are obtained based on the first random number and the generator. Using the general hash function, an anonymous signature is generated based on the query parameters, the blinding point, the encrypted registration public key, and the encrypted registration parameters. An identity encryption ciphertext is generated based on the temporary fake identity and the first random number. The obtained query parameter set is then sent to the server to request a data query from the server. The query parameter set includes the encrypted registration public key, the blinding point, the identity encryption ciphertext, and the anonymous signature.

[0012] Optionally, after successful verification of the anonymous signature, the server queries the historical word list set based on the target hash value, encrypts the query result using the blinding point and the generated third random number, and obtains the privacy data set, including: Verify the anonymous signature according to the query verification equation; If the verification is successful, retrieve the historical keywords in the historical word list set whose historical short hash values ​​are the same as the target hash value, and retrieve the report data corresponding to the historical keywords; The report data is encrypted using the blinding point, the generated third random number, and the generator to obtain the privacy data set.

[0013] Optionally, generating the identity encryption ciphertext based on the temporary fake identity and the first random number includes: Using the general hash function, a query hash value is obtained based on the query string, wherein the system public key and the first random number are multiplied together and the target hash value and the blinding point to obtain the query string; The query hash value and the temporary fake identity are XORed bit by bit to obtain the encrypted identity ciphertext, which is used by the server for identity verification.

[0014] Optionally, the server is also used for: Decrypting the encrypted identity ciphertext yields the fake identity to be verified; Based on the fake identity to be verified, a parsed encrypted ciphertext is generated. The parsed encrypted ciphertext is used by the user to verify information before decrypting the privacy data set.

[0015] Secondly, the present invention provides a privacy query device for wireless body area networks, comprising: An initialization module is used to complete user registration with the trusted authorization center based on the user's identity information after system initialization. The system initialization includes the trusted authorization center obtaining and publishing public parameters using elliptic curve cryptography, and the server organizing a set of historical word lists based on the key hash values ​​corresponding to historical keywords. The request module is used to obtain the target hash value of the target keyword, generate a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters, generate encryption parameters based on the blinding factor, perform blinding processing based on the generated first random number, second random number, the public parameters, the blinding factor, and the target hash value to obtain a blinding point, perform anonymous encryption processing on the temporary fake identity to obtain an anonymous signature, and send a data query request to the server. The query module is used to decrypt the privacy data set returned by the server based on the second random number and the target keyword to obtain a privacy query result. The server is used to query the historical word list set based on the target hash value after the anonymous signature is successfully verified, and encrypt the query result using the blinding point and the generated third random number to obtain the privacy data set.

[0016] The beneficial effects of the privacy query method for wireless body area networks of the present invention are as follows: Elliptic curve cryptography is used by a trusted authorization center to obtain and publish public parameters, replacing the complex parameter construction methods based on bilinear pairings and group signatures in existing technologies. Elliptic curve cryptography has the characteristic of low computational complexity, significantly reducing the computational overhead of terminal devices and servers, and adapting to the limited computing resources of medical terminals in wireless body area networks. Simultaneously, the server obtains a historical word list by organizing the hash values ​​of historical keywords, and groups the entire database according to hash values. Subsequent queries only need to search for the target group, avoiding the inefficient operation of traversing the entire database. This improves query efficiency from the perspective of data storage and retrieval, solving the problems of heavy computational burden and low retrieval efficiency in existing solutions. Based on unified registration with the trusted authorization center using identity information, users only need to store core parameters such as identity information and system registration public key issued by the trusted authorization center. There is no need to pre-store a large number of pseudonymous certificates and corresponding private keys as in existing technologies, which significantly reduces the storage pressure on user-side terminal devices. This avoids the communication delays and verification overhead caused by frequent certificate changes and revocation list expansions under the existing pseudonymous certificate mechanism. At the same time, the unified authentication by the trusted authorization center ensures the legitimacy of the user's identity, preventing malicious querying by unauthorized personnel from the source, and solving the problems of high terminal storage pressure and high communication verification costs in existing solutions. By generating a blinding factor using temporary fake identities and identity information, and then generating encrypted parameters based on this factor, blinding points and anonymous signatures are generated by combining random numbers and public parameters. On the one hand, the dual design of blinding factors and blinding points achieves dual privacy protection for user identity and query keywords, preventing the server from associating user's historical query trajectory with fixed authentication credentials and ensuring the unlinkability of query behavior. On the other hand, the generation and transmission of anonymous signatures achieves legitimate verification of user identity. Both signature generation and verification are based on elliptic curve cryptography and hash operations, without high-complexity cryptographic operations, making them suitable for low-power medical terminals. At the same time, the anonymous encryption processing of temporary fake identities further enhances the security of identity privacy protection, effectively solving the problems of existing solutions such as the separation of authentication and query, vulnerability to signature forgery and replay attacks, and poor privacy protection. The server retrieves and encrypts data only after successful anonymous signature verification. This verification-before-query design avoids processing invalid data from illegal requests, improving the server's query processing efficiency. Simultaneously, the server uses blinding points and a third random number to encrypt the query results. Only legitimate users can decrypt the data using their own second random number and target keywords, achieving precise encryption and decryption of the query data. This ensures users can only access the target query data, preventing the leakage of sensitive medical data. Furthermore, this encryption and decryption method is based on collaborative computation using preset parameters, making it simple to operate and computationally efficient, solving the problems of high data encryption and decryption complexity and susceptibility to data leakage in existing solutions.

[0017] This invention constructs a full-process privacy query system based on elliptic curve cryptography, avoiding highly complex operations such as bilinear pairing and group key updates throughout the process. It is adapted to the limited computing and storage resources of medical terminal devices in wireless body area networks, significantly reducing the computing, storage, and communication overhead on both the user and server sides, effectively improving the overall efficiency of remote medical queries and solving the technical problems of high computational complexity, large communication latency, and low query efficiency in existing technologies. Simultaneously, through multiple privacy protection designs including blinding factors, blinding points, temporary pseudo-identities, and anonymous signatures, it achieves dual protection of user anonymity and the non-linkability of query behavior. Furthermore, combined with registration and authentication by a trusted authorization center and signature verification by the server, it constructs a full-process identity verification mechanism, effectively resisting security threats such as signature forgery, replay attacks, and man-in-the-middle attacks, thus improving the overall security of remote medical query services. In addition, the parameter design and process architecture of this invention, while achieving strong privacy protection, retain the trusted authorization center's ability to trace user identities, effectively balancing the dual needs of user privacy protection and malicious behavior monitoring, and effectively achieving a balance between privacy protection and regulatory requirements for remote medical queries. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the privacy query method for wireless body area networks according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a privacy query device for wireless body area networks according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0019] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0020] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0021] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0022] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0023] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0024] like Figure 1 As shown in the figure, an embodiment of the present invention provides a privacy query method for wireless body area networks, characterized in that it includes: Step S1: After system initialization, user registration is completed based on the user's identity information and the trusted authorization center. The system initialization includes the trusted authorization center using elliptic curve cryptography to obtain and publish public parameters, and the server organizing a set of historical word lists based on the key hash values ​​corresponding to historical keywords.

[0025] Specifically, before user registration, the system needs to be initialized. Medical data carried by the wireless body area network (WBN) is sensitive and private, requiring assurance of user legitimacy from the source. Simultaneously, a unified and secure cryptographic computing infrastructure must be established to provide common parameters for subsequent privacy queries, including authentication, data encryption / decryption, and keyword blinding. This prevents unauthorized users from initiating queries, thus strengthening the security defenses for remote medical queries from the root. The server performs hash grouping of historical keywords, narrowing the search scope of subsequent queries from the entire database to specified groups, significantly reducing server computation and communication overhead and adapting to the low-power, resource-constrained characteristics of WBN terminal devices.

[0026] Public parameters serve as the unified cryptographic foundation for elliptic curve cryptography operations, identity authentication, data encryption / decryption, and keyword blinding among the trusted authorization center, user, and server throughout the entire privacy query process in a wireless body area network (WBN). They are a prerequisite for the secure, effective, and compatible operation of the entire privacy query system. Generating public parameters using elliptic curve cryptography offers advantages over traditional public-key cryptography, bilinear pairing, and group signature technologies. At the same security level, it features smaller parameter size and lower computational complexity, making it suitable for the low-power, resource-constrained scenarios of medical terminal devices in WBNs. Selecting relevant parameters based on cryptographic security standards ensures the anti-attack properties of public parameters from the source, preventing security issues such as privacy leaks and signature forgery caused by non-standard parameter design. Furthermore, publicly available public parameters provide a unified standard for the three parties' operations, avoiding incompatibility issues during the interaction process.

[0027] Optionally, the trusted authorization center uses elliptic curve cryptography to obtain and publish public parameters, including: Using the elliptic curve cryptography described above, the prime order, the corresponding prime field, and the elliptic curve are obtained based on cryptographic security standards, and the additive cyclic group and generator corresponding to the prime order are generated.

[0028] Specifically, the Trusted Authorization Center (TA) employs elliptic curve cryptography, adheres to cryptographic security standards (such as the Chinese national standard SM2 and the NIST elliptic curve standard), selects a large prime number as its prime order q, and determines the prime field F that matches this prime order q. p , where p is a large prime number that fits q, and an elliptic curve E on the prime order q is selected; based on the selected elliptic curve E, an additive cyclic group G with prime order q is generated, and an original point in the additive cyclic group G is selected as a generator P, which is the basis for the elliptic curve dot product operation.

[0029] The system public key is obtained based on the generator and the system master private key.

[0030] Specifically, from the nonzero multiplicative group Z of prime order q q A large integer is randomly selected as the system master private key sk. The system master private key is a core confidential parameter of the trusted authorization center and is held only by the center itself. The system master private key sk is operated on with the generator P through elliptic curve dot product to obtain the system public key PK, which is expressed as: PK = sk·P. The system public key is a public parameter and is publicly disclosed as part of the public parameters.

[0031] The common parameters are obtained based on the acquired general hash function and short hash function, as well as the additive cyclic group, the generator, the prime order corresponding to the additive cyclic group, and the system public key.

[0032] Specifically, two hash functions with cryptographic security properties are selected: a general hash function H1 and a short hash function H2. H1 can be a mapping function from a binary string of arbitrary length to a binary string of fixed length l, i.e., H1: {0, 1}. →{0,1} l Where l represents the output length of the general hash function H1, and H2 is H2:{0,1} →{0, 1, ..., 127}. The generated additive cyclic group G, generator P, prime order q corresponding to the additive cyclic group, and system public key PK are integrated with the selected first hash function H1 and second hash function H2 to obtain the complete set of public parameters {G, q, P, PK, H1, H2}.

[0033] The public parameters are disclosed to the user and the server.

[0034] Specifically, the integrated set of public parameters is made public to users and servers through a secure broadcast method, ensuring that all participants can obtain and use them synchronously, thus laying the parameter foundation for subsequent steps such as user registration and data query.

[0035] This embodiment selects fundamental parameters based on elliptic curve cryptography (ECC) in accordance with cryptographic security standards, ensuring the security and resistance to attacks of the public parameters and laying a solid security foundation for the entire privacy query system from the source. By generating public parameters using ECC, high-complexity operations such as bilinear pairing are avoided, adapting to the resource limitations of wireless body area network (WBN) medical terminals. Simultaneously, the randomly generated system master private key forms a public-private key pair with the publicly available system public key, providing secure cryptographic support for subsequent identity authentication and registration verification. By integrating multiple core cryptographic parameters into a unified public parameter set, the computational standards of the trusted authorization center, users, and servers are unified, avoiding computational incompatibility issues during interaction. This provides a standardized, secure, and efficient cryptographic foundation for subsequent end-to-end privacy query operations. Furthermore, the combination of hash functions and ECC parameters addresses multiple needs such as identity authentication, data encryption, and keyword grouping, enhancing the practicality and adaptability of the public parameters.

[0036] Optionally, the server compiles a historical word list based on the key hash values ​​corresponding to historical keywords. This is a core step for server S to complete its own cryptographic identity system construction and medical data keyword preprocessing. The generation of the server's private and public keys provides dedicated cryptographic support for subsequent encryption of query data and user interaction verification, ensuring the uniqueness and security of server-side data encryption. Grouping historical keywords into short hashes and generating a historical word list narrows the search scope for subsequent user queries from the entire database to a list of words corresponding to the hash values, significantly reducing the server's retrieval and encryption computational overhead. This adapts to the real-time and lightweight query requirements of wireless body area networks. Simultaneously, the unidirectional nature of the short hash function prevents the server from deducing the original keywords from the hash values, ensuring keyword privacy and laying the foundation for subsequent precise user queries based on target hash values. Specifically, this includes: The server public key is obtained based on the randomly generated server private key and the generator.

[0037] Specifically, the server publishes the prime multiplication group Z in the trusted authorization center. q In the process, a scalar value is randomly selected as the server's private key sk. S The server's private key sk S This is a dedicated, private storage for the server, used only for subsequent medical data encryption and ciphertext generation, and is not publicly disclosed. Subsequently, the server calls the elliptic curve generator P, publicly available from the trusted authorization center during the system initialization phase, and uses elliptic curve scalar multiplication to convert the server's private key sk... S The elliptic curve group elements obtained by performing operations with the generator P are the server public key PK. S , represented as: PK S =sk S ·P. Server public key PK S It can be made public for subsequent user interaction verification.

[0038] For historical keywords in the database, the short hash function is used to calculate the historical short hash value corresponding to each historical keyword.

[0039] Specifically, the server retrieves all historical keywords W associated with medical data from the locally stored medical database. i According to the short hash function H2 in the public parameters published by the Trusted Authorization Center, for each historical keyword W i Perform hash operations sequentially to process historical keywords W of arbitrary length. i The mapping is to a fixed-length scalar value, which is the short historical hash value h corresponding to each historical keyword. 历 , represented as h 历 =H2(W iDuring the calculation, the same historical keyword W is guaranteed. i The hash operation result is unique, and different historical keywords W i Can be mapped to the same historical short hash value h 历 .

[0040] The historical keywords corresponding to the same historical short hash value are organized into a word list to generate the historical word list set.

[0041] Specifically, the server uses historical short hash values ​​h 历 Based on the classification criteria, all historical keywords W were used. i The data will be categorized and organized, and short hash values ​​W with the same historical data will be grouped together. i All historical keywords W i Integrate into a single word list L hj (j=0, 1, ..., 127), where L is a list of words. hj (j=0, 1, ..., 127) are bound to the corresponding historical short hash value identifiers; all historical keywords W are pending. i After classification, all lists of individual words bound to hash values ​​are integrated into a set {L}. h0 L h1 , ..., L h127 This set is the historical word list, which the server stores locally as the core retrieval basis for subsequent user queries.

[0042] This embodiment constructs a dedicated elliptic curve cryptography public-private key system for the server by randomly generating a private key and combining it with generators to obtain a public key. This ensures the security and uniqueness of subsequent data encryption and interactive verification, and is compatible with the elliptic curve cryptography operation framework of the entire system. Historical short hash values ​​are obtained by uniformly operating on historical keywords using a short hash function, achieving a fixed-length mapping for keywords of arbitrary length, facilitating subsequent classification and organization. Furthermore, a historical word list is generated based on these short hash values, optimizing the full-database search of the medical database into a targeted group search. This significantly reduces the search scope and computational overhead when the server responds to subsequent query requests, improving query processing efficiency and adapting to the resource-constrained and low-latency requirements of wireless body area networks. Simultaneously, the lightweight nature of short hash operations further reduces the server's preprocessing costs, laying a data foundation for efficient and privacy-preserving queries.

[0043] Optionally, after system initialization, user registration is completed based on identity information and a trusted authorization center. User registration is a core step in the wireless body area network privacy query system to achieve identity access. The trusted authorization center verifies the legitimacy of user identity and distributes exclusive authentication parameters, filtering unauthorized users at the source and preventing the unauthorized access of sensitive medical data. Simultaneously, a unique system registration public key and registration authentication parameters are generated for legitimate users, serving as the core basis for identity authentication and parameter blinding when users initiate privacy queries, ensuring the effectiveness and privacy of identity verification during the query process. The design of the registration verification equation allows users to independently verify the authenticity and completeness of the parameters returned by the authorization center, preventing parameters from being tampered with during transmission, ensuring the security of the registration process, and building a legitimate user identity foundation for subsequent full-process privacy queries. Specifically, this includes: Obtain the identity information and send the identity information and registration request to the trusted authorization center.

[0044] Specifically, the user's UI first collects their own unique and authentic identity information (ID). i This identity information ID i This serves as the user's identity identifier within the wireless body area network privacy query system, and subsequently, this identity information ID... i It is integrated with standardized registration request instructions and sent to a trusted authorization center through a secure channel to formally initiate the registration application. The secure channel ensures that identity information is not stolen or tampered with during transmission.

[0045] The registration authentication parameters fed back by the trusted authorization center are verified according to the registration verification equation. The trusted authorization center is used to obtain the system registration public key based on the generated registration random number and the generator, generate the registration authentication parameters based on the public parameters, the system registration public key, the identity information and the registration random number, and feed back the system registration public key and the registration authentication parameters to the user.

[0046] If verification is successful, the user information is obtained, including the identity information, the system registration public key, and the registration authentication parameters; if verification fails, the registration is terminated.

[0047] Specifically, the trusted authorization center receives the user's registration request and identity information ID. i Next, verify the identity information ID. i The validity of the data is verified, and then it is used in the prime factorial group Z. q A scalar value is randomly generated as the registration random number x. iThe generator P, publicly available during the system initialization phase, is invoked. The registered random number xi is then processed by elliptic curve scalar multiplication with generator P. The resulting elliptic curve group elements are the system registration public key X. i , represented as: X i =x i •P. Then, relying on the public parameters disclosed during the system initialization phase, combined with the generated system registration public key X... i User's identity information ID i And the registration random number x i The registration and authentication parameters C are generated through cryptographic operations such as hash function H1 and elliptic curve scalar multiplication. i Finally, the generated system registration public key and registration authentication parameters are sent back to the user who initiated the registration via a secure channel. After receiving the system registration public key and registration authentication parameters from the trusted authorization center, the user retrieves the relevant cryptographic parameters from the public parameters and verifies the validity and integrity of the registration authentication parameters according to the preset registration verification equation. The verification process is an elliptic curve cryptography operation verification, where the registration verification equation is expressed as: C i ·P=H1(ID i ||X i )·PK t +X i Only when the registration authentication parameter C i When the registration verification equation is matched, the verification is considered successful; after successful verification, the user will enter their identity information (ID). i The system registration public key X returned by the trusted authorization center i And registration and authentication parameters C i Integrate and generate unique user information {ID} i C i X i} and store it on the local terminal to complete the entire registration process; if the registration authentication parameter C i If the registration verification equation does not match, the verification is deemed unsuccessful, the user terminates the registration process directly, no relevant parameters are stored, and the user is unable to obtain the permission to initiate subsequent privacy queries.

[0048] This embodiment achieves legitimate identity access to the privacy query system through pre-verification of user identity information by a trusted authorization center, preventing unauthorized user queries from the source and ensuring the security of medical data access. The trusted authorization center generates a unique system registration public key and registration authentication parameters for legitimate users, providing a unique and legitimate cryptographic basis for identity authentication and parameter blinding when users initiate queries, and is compatible with the elliptic curve cryptography framework of the entire system. The design of the registration verification equation allows users to independently verify the authenticity of the feedback parameters, avoiding the security risk of parameter transmission tampering. At the same time, users only need to store a small amount of core information such as identity information, system registration public key, and registration authentication parameters, without the need to pre-store a large number of certificates, greatly reducing the storage pressure on user-side terminal devices and adapting to the resource-constrained characteristics of wireless body area network medical terminals. The entire registration process is simple to operate and computationally lightweight, laying a legitimate user identity foundation for efficient and secure privacy queries.

[0049] Step S2: Obtain the target hash value of the target keyword, and generate a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters. Generate encryption parameters based on the blinding factor, perform blinding processing based on the generated first random number, second random number, the public parameters, the blinding factor, and the target hash value to obtain a blinding point, perform anonymous encryption processing on the temporary fake identity to obtain an anonymous signature, and send a data query request to the server.

[0050] Specifically, by generating blinding factors, the core authentication parameters of users are blinded, preventing the server from associating users' real identities with fixed parameters. Blinding points are generated to hide query keywords, preventing the server from deducing specific target keywords from these points. Anonymous signatures are generated to verify the legitimacy of user identities by the server. Simultaneously, identity encryption, keyword blinding, and query requests are integrated into a single interaction, avoiding the increased communication rounds and vulnerability to attacks caused by the separation of authentication and query processes, thus adapting to the real-time requirements of wireless body area networks.

[0051] Optionally, obtaining the target hash value of the target keyword and generating a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters is a core preliminary step in achieving query keyword privacy protection and user identity anonymization. Specifically, this includes: The target hash value of the target keyword is obtained using the short hash function.

[0052] Specifically, the user determines the medical-related target keyword W to be searched. 目 Then, the short hash function H2 from the public parameters disclosed by the Trusted Authorization Center during the system initialization phase is retrieved. Following the operation rules of this short hash function H2, the target keyword W is processed. 目Perform a one-way hash operation to map a target keyword of arbitrary length to a scalar value of fixed length; this scalar value is the target hash value h. 目 , represented as: h 目 =H2(W 目 The calculation process ensures that the same target keyword W is used. 目 The hash result is unique and cannot be obtained from the target hash value h. 目 Back-engineering the original target keyword W i .

[0053] Using the hash function, the original hash value is obtained by concatenating the identity information and the system registration public key into an identity string, and a temporary hash value is obtained based on the temporary fake identity.

[0054] Specifically, the user retrieves their stored identity information ID. i and system registration public key X i The two are concatenated into a complete identity string according to a preset format, such as "identity information || system registration public key", which is the ID. i ||X i Then, the general hash function H1 in the public parameters is called to perform a hash operation on the identity string, obtaining a fixed-length scalar value, which is the original hash value H1(ID). i ||X i) This value is strongly linked to the user's real identity and forms the basis for generating the blinding factor. A temporary fake identity (PID) is randomly generated for each user for this query. i Even if it has no real identity association, the general hash function H1 in the public parameters is still called to process the temporary fake identity PID. i Performing a hash operation yields a fixed-length scalar value, which is the temporary hash value H1 (PID). i This value is a random dynamic factor for this query, used to break the fixed association between the original hash value and the user's identity.

[0055] The blinding factor is obtained based on the temporary hash value and the original hash value.

[0056] Specifically, the user bases the temporary hash value H1 (PID) generated by the user. i ) and the original hash value H1 (ID) i ||X i ), in the prime factorial group Z q Scalar operations are performed on it, typically using a temporary hash value H1 (PID). i ) and the original hash value H1(ID) i ||X iPerforming a scalar multiplication on the inverse of PID, the resulting scalar value is the blinding factor t, expressed as: t = H1(PID) i )(H1(ID i ||X i -1. The blinding factor also functions as a temporary false identity (PID). i The dynamism and uniqueness of user identity-related parameters are the core factors for subsequent blind encryption of system registration public keys and registration authentication parameters.

[0057] This embodiment transforms target keywords into target hash values ​​using a short hash function, achieving privacy hiding of query keywords. The server can only retrieve data based on the hash value and cannot know the user's specific query content, thus ensuring the privacy of the query behavior. Simultaneously, an original hash value is generated based on the user's real identity parameters, and a temporary hash value is generated based on a temporary fake identity. The two are then used to calculate a blinding factor. This maintains the correlation with the user's identity to ensure the validity of subsequent authentication, while the dynamic nature of the temporary fake identity breaks the traceability of fixed identity parameters, achieving anonymization of the user's identity. The entire process involves only hash and scalar operations, without highly complex elliptic curve operations, making it lightweight and efficient. It is well-suited to the resource-constrained characteristics of wireless body area network medical terminals, providing a secure and dynamic core factor for the subsequent generation of encryption parameters and blinding points, balancing identity anonymity, keyword privacy, and computational efficiency.

[0058] Optionally, the step of performing blinding processing based on the generated first random number, second random number, the public parameter, the blinding factor, and the target hash value to obtain a blinding point, performing anonymous encryption processing on the temporary false identity to obtain an anonymous signature, and making a data query request to the server includes: The blinding point is obtained based on the second random number, the generator, and the target hash value.

[0059] Specifically, the user in the prime factorial multiplication group Z q A scalar value is randomly generated as the second random number q. i Retrieve the generators disclosed during the system initialization phase and the calculated target hash value h. 目 Blinding is achieved through elliptic curve scalar multiplication and addition: First, calculate the two elliptic curve points "second random number × generator" and "target hash value × generator" respectively. Then, perform elliptic curve addition on the two points. The resulting elliptic curve group element is the blinding point Q, expressed as: Q = q i ·P+h 目 • P. This blinding point Q is only related to the target hash value and the first random number, and cannot be used to deduce the original target keyword.

[0060] The system registration public key and the registration authentication parameters are encrypted using the blinding factor to obtain the encrypted registration public key and encrypted registration parameters. The query parameters are obtained based on the first random number and the generator.

[0061] Specifically, the user invokes the generated blinding factor t to register the system public key X stored in their own system. i Registration and authentication parameters C i Performing elliptic curve scalar multiplication encryption, i.e., "blinding factor × system registration public key", yields the encryption registration public key X. i * , represented as: X i * =t·X i The encrypted registration parameter C is obtained by multiplying the blinding factor by the registration authentication parameter. i * , represented as: C i * =t·C i Together, these two constitute the encryption parameters. The user uses the prime factorial group Zq... Another scalar value is randomly generated as the first random number d. i The generator is invoked to perform elliptic curve scalar multiplication, i.e., "first random number × generator", and the resulting elliptic curve group element is the query parameter D. i , represented as: D i =d i ·P, the query parameter D i This provides a core basis for subsequent anonymous signature generation and data decryption.

[0062] Using the hash function, an anonymous signature is generated based on the query parameters, the blinding point, the encrypted registration public key, and the encrypted registration parameters. An identity encrypted ciphertext is generated based on the temporary fake identity and the first random number. The obtained query parameter set is sent to the server to make a data query request to the server. The query parameter set includes the encrypted registration public key, the blinding point, the identity encrypted ciphertext, and the anonymous signature.

[0063] Specifically, the user will query parameter D i Blinding point Q, encrypted registration public key X i * Target hash value h 目 The timestamp T1, representing the time sequence information, is concatenated into a signature input string according to a preset format. The general hash function in the public parameters is then used to perform a hash operation on this string to obtain the signature hash value. The signature hash value is then compared with the encrypted registration parameter C. i *Performing elliptic curve scalar multiplication and adding it to the first random number yields the anonymous signature S. i =H1(X i * ||D i ||T1||h 目 ||Q)C i * +d i The anonymous signature can be verified by the server, but the user's real identity cannot be deduced.

[0064] Optionally, generating the identity encryption ciphertext based on the temporary fake identity and the first random number includes: Using the hash function, a query hash value is obtained based on the query string, wherein the system public key and the first random number are multiplied together with the target hash value and the blinding point to obtain the query string.

[0065] The query hash value and the temporary fake identity are XORed bit by bit to obtain the encrypted identity ciphertext, which is used by the server for identity verification.

[0066] Specifically, the user will PK the system public key. t With the first random number d i Perform elliptic curve scalar multiplication, and combine the result with the target hash value h. 目 The blinding point Q and its corresponding timestamp T1 are concatenated into a query string, and the general hash function H1 is called to calculate the query hash value; the query hash value is then combined with the temporary fake identity PID. i Performing a bitwise XOR operation on each binary bit yields the binary string, which is the encrypted ciphertext CT1, represented as CT1=H1(d i ·PK t ||T1||h 目 ||Q)⊕PID i The user will encrypt the registration public key X. i * Blinding point Q, identity encryption ciphertext CT1, anonymous signature S i And the timestamp T1 is integrated into the query parameter set {X i * CT1, T1, Q, S i The system then sends the parameter set to the server via a wireless body area network communication link, formally initiating a medical data privacy query request.

[0067] This embodiment generates blinding points by combining a first random number with a target hash value, achieving deep privacy protection for query keywords. The server can only encrypt data based on the blinding points and cannot know the user's true query content. By using a blinding factor to encrypt the system registration public key and registration authentication parameters to generate encrypted parameters, and combining this with the query parameters to generate an anonymous signature, the server's verification of user identity legitimacy is ensured while preventing the leakage of real identity parameters, achieving a balance between identity anonymity and legitimate authentication. The generation of encrypted identity ciphertext further strengthens the privacy protection of temporary fake identities, preventing identity information from being stolen during transmission. Simultaneously, all core parameters are integrated into a single query parameter set and sent, avoiding multiple interactions between authentication and query, reducing communication rounds and terminal computational overhead, and adapting to the resource-constrained characteristics of wireless body area network medical terminals. The entire process involves only lightweight operations such as elliptic curve scalar multiplication / addition, hashing, and XOR. While ensuring identity anonymity, keyword privacy, and data security, it significantly improves the efficiency of query request initiation, laying a secure and efficient foundation for subsequent server-side verification and data feedback.

[0068] Step S3: Decrypt the privacy data set returned by the server according to the second random number and the target keyword to obtain the privacy query result. The server is used to query the historical word list set according to the target hash value after the anonymous signature is successfully verified, and encrypt the query result using the blinding point and the generated third random number to obtain the privacy data set.

[0069] Specifically, before the user decrypts the privacy data set, the server first verifies the relevant data sent by the user and then queries the medical data based on the verification results: Optionally, after successful verification of the anonymous signature, the server queries the historical word list set based on the target hash value, encrypts the query result using the blinding point and the generated third random number, and obtains the privacy data set, including: The anonymous signature is verified according to the query verification equation.

[0070] Specifically, the server receives the query parameter set {X} sent by the user. i * CT1, T1, Q, S i After that, retrieve the general hash function H1, generator P, and system public key PK from the public parameters. t The system uses core parameters such as S to verify the legitimacy of anonymous signatures according to a pre-defined query verification equation. This query verification equation, based on elliptic curve cryptography, is expressed as: S i ·P=H1(X i * ||D i ||T1||h目 ||Q)(H1(PID i )·PK t +X i * )+D i If the query verification equation is true, the anonymous signature verification is considered successful; otherwise, the query request is rejected.

[0071] If the verification is successful, obtain the historical keywords in the historical word list set whose historical short hash values ​​are the same as the target hash value, and retrieve the report data corresponding to the historical keywords.

[0072] Specifically, if the verification is successful, the server continues to perform medical data query operations, extracts the target hash value h from the query parameter set, retrieves the historical short hash value h from the locally stored historical word list set, extracts all related historical keywords Wi from the word list, and retrieves all report data Dai corresponding to these historical keywords Wi from the medical database to complete accurate data retrieval and avoid the inefficient operation of full database traversal.

[0073] The report data is encrypted using the blinding point, the generated third random number, and the generator to obtain the privacy data set.

[0074] Specifically, the server is in the prime multiplication group Z. q A scalar value is randomly generated as the third random number y. The generator P from the public parameters and the blinding point Q sent by the user are retrieved. Elliptic curve cryptography is used to generate the data encryption key Y, expressed as: Y = y·P. Using this data encryption key Y as the core key, a symmetric encryption algorithm (such as AES) is employed to encrypt all retrieved report data piece by piece, resulting in the encrypted report data CT2. i , represented as: CT2 i =D ai ⊕H1(y·(Qh 目 ·P)||H1(W i ), where i = 0, 1, 2, ..., N-1. All encrypted report data are integrated into a set, which is the privacy data set {CT21, CT22, ..., CT2...}. N}

[0075] Optionally, the server is also used for: The encrypted identity is decrypted to obtain the fake identity to be verified.

[0076] Based on the fake identity to be verified, a parsed encrypted ciphertext is generated. The parsed encrypted ciphertext is used by the user to verify information before decrypting the privacy data set.

[0077] Specifically, in addition to verifying the anonymous signature, the server also generates a parsed encrypted ciphertext V for users to verify information before decrypting the privacy data set. i After successful anonymous signature verification, the server retrieves the encrypted identity ciphertext CT1 from the query parameter set. Combining this with its stored system public key, the user-sent blinding point, and the target hash value, it decrypts the ciphertext CT1 generated by the user in reverse order. The result is the fake identity PID to be verified. i1 Based on the PID of the fake identity to be verified obtained through decryption. i1 It retrieves its own server public key, current timestamp T2, and other parameters, and generates the encrypted ciphertext V using a general hash function H1. i , represented as: V i =H1(y·D i ||D i ||Y||PID i1 ||T2). This decodes the encrypted ciphertext V. i It includes server identity and data integrity verification information, which is used by users to verify the legitimacy of the data source.

[0078] After the server completes the above operations, it will store the privacy data set {CT21, CT22, ... CT2...} N} and decrypting encrypted ciphertext V i This data is then fed back to the user. The user receives a set of privacy data {CT21, CT22, ... CT2} from the server. N} and decrypting encrypted ciphertext V i Next, the information is verified by parsing the encrypted ciphertext to confirm that the data comes from a legitimate server and has not been tampered with; that is, the PID of the fake identity to be verified is obtained after parsing. i1 Is it related to the temporary identity PID? i If the numbers are the same, the verification is successful; otherwise, the verification fails. The second random number q generated in this query is then called. i Combined with the target keyword W that you have determined 目 The system calculates a unique decryption key using a preset decryption algorithm. This key is then used to decrypt the encrypted medical data in the privacy data set one by one. Due to the cryptographic characteristics of unintentional transmission, only medical data matching the target keywords can be successfully decrypted. The remaining data will be invalid gibberish after decryption. The successfully decrypted medical data is the final result of this privacy query.

[0079] This invention employs elliptic curve cryptography through a trusted authorization center to obtain and publish public parameters, replacing the complex parameter construction methods based on bilinear pairings and group signatures in existing technologies. Elliptic curve cryptography has the characteristic of low computational complexity, significantly reducing the computational overhead of terminal devices and servers, and adapting to the limited computing resources of medical terminals in wireless body area networks. At the same time, the server obtains a historical word list by organizing the hash values ​​of historical keywords, and groups the entire database data according to hash values. Subsequent queries only need to search for the target group, avoiding the inefficient operation of traversing the entire database. This improves query efficiency from the perspective of data storage and retrieval, solving the problems of heavy computational burden and low retrieval efficiency in the query process of existing solutions. Based on unified registration with the trusted authorization center using identity information, users only need to store core parameters such as identity information and system registration public key issued by the trusted authorization center. There is no need to pre-store a large number of pseudonymous certificates and corresponding private keys as in existing technologies, which significantly reduces the storage pressure on user-side terminal devices. This avoids the communication delays and verification overhead caused by frequent certificate changes and revocation list expansions under the existing pseudonymous certificate mechanism. At the same time, the unified authentication by the trusted authorization center ensures the legitimacy of the user's identity, preventing malicious querying by unauthorized personnel from the source, and solving the problems of high terminal storage pressure and high communication verification costs in existing solutions. By generating a blinding factor using temporary fake identities and identity information, and then generating encrypted parameters based on this factor, blinding points and anonymous signatures are generated by combining random numbers and public parameters. On the one hand, the dual design of blinding factors and blinding points achieves dual privacy protection for user identity and query keywords, preventing the server from associating user's historical query trajectory with fixed authentication credentials and ensuring the unlinkability of query behavior. On the other hand, the generation and transmission of anonymous signatures achieves legitimate verification of user identity. Both signature generation and verification are based on elliptic curve cryptography and hash operations, without high-complexity cryptographic operations, making them suitable for low-power medical terminals. At the same time, the anonymous encryption processing of temporary fake identities further enhances the security of identity privacy protection, effectively solving the problems of existing solutions such as the separation of authentication and query, vulnerability to signature forgery and replay attacks, and poor privacy protection. The server retrieves and encrypts data only after successful anonymous signature verification. This verification-before-query design avoids processing invalid data from illegal requests, improving the server's query processing efficiency. Simultaneously, the server uses blinding points and a third random number to encrypt the query results. Only legitimate users can decrypt the data using their own second random number and target keywords, achieving precise encryption and decryption of the query data. This ensures users can only access the target query data, preventing the leakage of sensitive medical data. Furthermore, this encryption and decryption method is based on collaborative computation using preset parameters, making it simple to operate and computationally efficient, solving the problems of high data encryption and decryption complexity and susceptibility to data leakage in existing solutions.

[0080] This invention employs elliptic curve cryptography to construct a comprehensive privacy query system, avoiding highly complex operations such as bilinear pairing and group key updates. It is well-suited to the limited computing and storage resources of medical terminal devices in wireless body area networks, significantly reducing computational, storage, and communication overhead on both the user and server sides. This effectively improves the overall efficiency of remote medical queries and solves the technical problems of high computational complexity, large communication latency, and low query efficiency in existing technologies. Furthermore, through multiple privacy protection designs including blinding factors, blinding points, temporary pseudo-identities, and anonymous signatures, it achieves dual protection of user anonymity and the non-linkability of query behavior. Combined with registration and authentication by a trusted authorization center and signature verification by the server, it constructs a comprehensive identity verification mechanism, effectively resisting security threats such as signature forgery, replay attacks, and man-in-the-middle attacks, thus enhancing the overall security of remote medical query services. In addition, the parameter design and process architecture of this invention, while achieving strong privacy protection, retain the trusted authorization center's ability to trace user identities, effectively balancing the dual needs of user privacy protection and malicious behavior monitoring, and achieving a balance between privacy protection and regulatory requirements in remote medical queries.

[0081] A specific example illustrates the method for querying medical privacy data in wireless body area networks: I. System Initialization Phase 1. Trusted Authorization Center (TA) generates and publishes public parameters. ①TA follows cryptographic security standards and uses elliptic curve cryptography to select the prime order q and the matching prime field F. p Construct an elliptic curve E and generate a prime-order additive cyclic group G, then select a generator P from the additive cyclic group G. ② In the prime factorial group Z q Randomly select the system master private key sk t And store it privately, using elliptic curve scalar multiplication to transfer the system's master private key sk. t The system public key PK is obtained by performing an operation with the generator P. t ; ③ Select a general-purpose hash function H1 and a short hash function H2 with cryptographic security properties, and integrate the additive cyclic group G, prime order q, generator P, and system public key PK. t And two hash functions H1 and H2, forming a common parameter set {G, q, P, PK}. t H1, H2}; ④ The common parameter set {G, q, P, PK} is transmitted via secure broadcast. t H1, H2} are exposed to all users Ui and server S, ensuring that the three parties obtain and use them synchronously and uniformly.

[0082] 2. The server constructs a public-private key system and generates a historical word list. ① Server S in prime factorial group Z q A scalar value is randomly selected as the server's private key sk. S It is then stored privately, and the generator P in the public parameters is called to obtain the server's public key PK through elliptic curve scalar multiplication. S And make it public; ② Server S retrieves all historical keywords W associated with medical data from the local medical database. i According to the short hash function H2 in the public parameters, for each historical keyword W i Perform hash operations sequentially to obtain the corresponding historical short hash value h. 历 ; ③ Server S uses historical short hash values ​​h 历 Based on the classification criteria, those with the same historical short hash value h are classified. 历 Historical keywords W i Integrated into a list of independent words L hj For each word list L hj Bind the corresponding historical short hash value h 历 Identify, then list all words L hj Integrate into a historical word list collection {L h0 L h1 , ..., L h127 Local storage serves as the core retrieval basis for subsequent queries.

[0083] II. User Registration Phase 1. User UI collects their own unique and authentic identity information ID. i Identity information ID i Integrated with the standardized registration request command, it is sent to the TA via a secure channel to formally initiate the registration application; 2. The TA receives the registration request and identity information (ID). i Next, verify the identity information ID. i The validity of the data is verified, and then it is used in the prime factorial group Z. q Randomly generate a registration random number x i The system registration public key X is obtained by calling the generator P through elliptic curve scalar multiplication. i ; 3. TA relies on common parameters {G, q, P, PK} t H1, H2}, combined with the system registration public key X i User identity information ID i And register random number x i The registration and authentication parameters C are generated through cryptographic operations such as hash function H1 and elliptic curve scalar multiplication.i Register the system public key X i And registration and authentication parameters C i Feedback is sent to the user's UI via a secure channel; 4. After receiving the feedback parameters, the user UI retrieves the relevant cryptographic parameters from the public parameters and performs the registration verification according to the preset registration verification equation Ci. P=H1(IDi||Xi) PKt+Xi verifies the validity and completeness of the registration and authentication parameter Ci. 5. If the verification equation is true, the verification is successful, and the user's UI will display their identity information (ID). i System registration public key X i And registration and authentication parameters C i Integrated into exclusive user information {ID} i C i X i The registration is completed on the local terminal; if the verification equation is not true, the verification is deemed to have failed, and user U... i The registration process is terminated directly, and no related parameters are stored.

[0084] III. Privacy Inquiry Request Stage 1. Obtain the target hash value and generate a blinding factor. ① User UI determines the medical-related target keywords to be queried this time. 目 Retrieve the short hash function H2 from the public parameters for the target keyword W. 目 Perform a one-way hash operation to obtain the corresponding target hash value h. 目 ; ② A temporary fake identity PID is randomly generated for each user's UI to be unique to this query. i Retrieve its own stored identity information ID i and system registration public key X i Concatenate them into an identity string ID according to a preset format. i ||X i Call the general hash function H1 to hash the identity string ID. i ||X i The operation yields the original hash value H1(ID). i ||X i Meanwhile, temporary fake identities (PIDs) are also being investigated. i The operation yields a temporary hash value H1 (PID). i ); ③ User Ui in the prime factorial group Zq In the process, a scalar multiplication operation is performed between the temporary hash value H1(PIDi) and the inverse of the original hash value H1(IDi||Xi) to obtain the blinding factor t.

[0085] 2. Generate blinding points, encryption parameters, and query parameters. ① User Ui in the prime factorial group Z q A second random number q is generated randomly. i Retrieve the generator P from the public parameters and the calculated target hash value h. 目 Two elliptic curve points are obtained by elliptic curve scalar multiplication, and then the two points are added together to obtain the blinded point Q. ② User Ui calls the generated blinding factor t to register the system public key X stored in its own system. i Registration and authentication parameters C i Perform elliptic curve scalar multiplication encryption to obtain the encryption registration public key X. i and encrypted registration parameter C i Both of these constitute the encryption parameters; ③ User Ui in the prime factorial group Z q The first random number d is generated randomly in the middle. i The generator P is called to obtain the query parameter D through elliptic curve scalar multiplication. i .

[0086] 3. Generate anonymous signature, encrypted identity text, and initiate a query. ① User Ui obtains the current timestamp T1, based on the general hash function H1 and query parameter D. i Blinding point Q, encrypted registration public key X i Target hash value h 目 Timestamp T1 and first random number d i Obtain anonymous signature S i ; ② User UI is based on the system public key PK t The first random number d i Target hash value h 目 Blinding point Q, timestamp T1, and temporary fake identity PID i Obtain the encrypted identity ciphertext; ③ User Ui will encrypt the registration public key X i Blinding point Q, identity encryption ciphertext CT1, anonymous signature S i And timestamp T1 are integrated into the query parameter set {X i CT1, T1, Q, S i The request for medical data privacy inquiry is formally initiated by sending a message to server S via a wireless body area network communication link.

[0087] IV. Server Verification and Data Encryption Feedback Phase 1. Server S receives the query parameter set {X} sent by user Ui. i CT1, T1, Q, S i After that, first verify the freshness of timestamp T1, then retrieve the general hash function H1, generator P, and system public key PK from the public parameters. t The core parameters are processed according to the preset query and verification equation S. i P=H 1 (X i ||Di||T1||h 目 ||Q)(H1(PID i ) PK t +X i )+D i For anonymous signature S i Perform a validity verification; if the timestamp T1 expires or the anonymous signature S... i If verification fails, server S directly rejects the query request; if all verifications pass, subsequent operations are performed.

[0088] 2. Server S retrieves the encrypted identity ciphertext CT1 from the query parameter set and combines it with the system public key PK. t The user sends the blinding point Q and the target hash value h. 目 Decrypt the encrypted ciphertext CT1 generated by the user to obtain the fake identity PID to be verified. i1 Server S is based on the PID of the fake identity to be verified. i1 Retrieve your own server's public key for PK S Using the current timestamp T2, generate the decrypted encrypted ciphertext V through a general hash function H1. i This encrypted text is used by users to subsequently verify the legitimacy and integrity of the data source.

[0089] 3. Server S extracts the target hash value h from the query parameter set. 目 The collection of historical word lists stored locally {L h0 L h1 , ..., L h127 In the}, retrieve the historical short hash value h 历 With the target hash value h 目 Consistent historical word list L hj Extract all related historical keywords W from this list. i And retrieve these historical keywords W from the medical database. iAll corresponding report data D ai Server S randomly generates a third random number y, retrieves the generator P and the blinding point Q sent by the user, and generates a data encryption key Y through elliptic curve cryptography. Using this key as the core, a symmetric encryption algorithm is employed to encrypt all retrieved report data D. ai Each report is encrypted individually, and all encrypted report data is then integrated into a privacy data set {CT21, CT22, ..., CT2...}. N}

[0090] 4. Server S will generate a privacy data set {CT21, CT22, ..., CT2...} N} and decrypting encrypted ciphertext V i The data is integrated into a response packet and fed back to the user UI that initiated the query via the wireless body area network communication link.

[0091] V. User Decryption and Result Acquisition Stage 1. After receiving the response data packet from server S, user UI first retrieves the relevant parameters stored within itself and then parses the encrypted ciphertext V. i The system verifies whether the data comes from a legitimate server and has not been tampered with. If the verification fails, the data packet is discarded. If the verification succeeds, the subsequent decryption operation is performed. 2. User UI calls the second random number q generated in this query. i Combined with the target keyword W that you have determined 目 A unique decryption key is calculated using a preset decryption algorithm; 3. User Ui uses a proprietary decryption key to access the privacy data set {CT21, CT22, ..., CT2...} N The encrypted medical data in the file is decrypted one by one. Relying on the cryptographic properties of unintentional transmission, the user can only successfully decrypt data related to the target keyword W. 目 The matched medical data is selected; the rest of the data will be invalid gibberish after decryption. The medical data that is successfully decrypted is the final result of this privacy query.

[0092] like Figure 2 As shown, an embodiment of the present invention provides a privacy query device 200 for wireless body area networks, comprising: The initialization module 210 is used to complete user registration with the trusted authorization center based on the user's identity information after system initialization. The system initialization includes the trusted authorization center obtaining and publishing public parameters using elliptic curve cryptography, and the server organizing a set of historical word lists based on the key hash values ​​corresponding to historical keywords. The request module 220 is used to obtain the target hash value of the target keyword, generate a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters, generate encryption parameters based on the blinding factor, perform blinding processing based on the generated first random number, second random number, the public parameters, the blinding factor, and the target hash value to obtain a blinding point, perform anonymous encryption processing on the temporary fake identity to obtain an anonymous signature, and send a data query request to the server. The query module 230 is used to decrypt the privacy data set returned by the server based on the second random number and the target keyword to obtain a privacy query result. The server, after successfully verifying the anonymous signature, queries the historical word list set based on the target hash value, encrypts the query result using the blinding point and the generated third random number, and obtains the privacy data set. Figure 3 As shown, an electronic device 300 provided in this embodiment of the invention includes a memory 310 and a processor 320; the memory 310 is used to store a computer program; the processor 320 is used to implement the privacy query method for wireless body area networks as described above when the computer program is executed.

[0093] Alternatively, an electronic device 300 includes a memory 310 and a processor 320 coupled to the memory 310; the memory 310 is configured to store a computer program; and the processor 320 is configured to perform the following operations when the computer program is executed: After system initialization, user registration is completed based on the user's identity information and the trusted authorization center. The system initialization includes the trusted authorization center using elliptic curve cryptography to obtain and publish public parameters, and the server organizing a set of historical word lists based on the key hash values ​​corresponding to historical keywords. Obtain the target hash value of the target keyword, and generate a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters. Generate encryption parameters based on the blinding factor, perform blinding processing based on the generated first random number, second random number, the public parameters, the blinding factor, and the target hash value to obtain a blinding point, perform anonymous encryption processing on the temporary fake identity to obtain an anonymous signature, and send a data query request to the server. The privacy data set returned by the server is decrypted based on the second random number and the target keyword to obtain a privacy query result. The server is used to query the historical word list set based on the target hash value after the anonymous signature is successfully verified, and encrypt the query result using the blinding point and the generated third random number to obtain the privacy data set.

[0094] This invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the privacy query method for wireless body area networks as described above.

[0095] Alternatively, a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the following operations: After system initialization, user registration is completed based on the user's identity information and the trusted authorization center. The system initialization includes the trusted authorization center using elliptic curve cryptography to obtain and publish public parameters, and the server organizing a set of historical word lists based on the key hash values ​​corresponding to historical keywords. Obtain the target hash value of the target keyword, and generate a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters. Generate encryption parameters based on the blinding factor, perform blinding processing based on the generated first random number, second random number, the public parameters, the blinding factor, and the target hash value to obtain a blinding point, perform anonymous encryption processing on the temporary fake identity to obtain an anonymous signature, and send a data query request to the server. The privacy data set returned by the server is decrypted based on the second random number and the target keyword to obtain a privacy query result. The server is used to query the historical word list set based on the target hash value after the anonymous signature is successfully verified, and encrypt the query result using the blinding point and the generated third random number to obtain the privacy data set.

[0096] The present invention will now be described an electronic device 300 that can serve as a server or client of the present invention, which is an example of a hardware device that can be applied to various aspects of the present invention. Electronic device 300 is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic device 300 can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0097] Electronic device 300 includes a computing unit that can perform various appropriate actions and processes based on a computer program stored in read-only memory (ROM) or a computer program loaded from a storage unit into random access memory (RAM). The RAM may also store various programs and data required for device operation. The computing unit, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0098] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc. In this application, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention according to actual needs. Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units can be implemented in hardware or as software functional units.

[0099] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A privacy query method for wireless body area networks, characterized in that, include: After system initialization, user registration is completed based on the user's identity information and the trusted authorization center. The system initialization includes the trusted authorization center using elliptic curve cryptography to obtain and publish public parameters, and the server organizing a set of historical word lists based on the key hash values ​​corresponding to historical keywords. Obtain the target hash value of the target keyword, and generate a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters. Generate encryption parameters based on the blinding factor, perform blinding processing based on the generated first random number, second random number, the public parameters, the blinding factor, and the target hash value to obtain a blinding point, perform anonymous encryption processing on the temporary fake identity to obtain an anonymous signature, and send a data query request to the server. The privacy data set returned by the server is decrypted based on the second random number and the target keyword to obtain a privacy query result. The server is used to query the historical word list set based on the target hash value after the anonymous signature is successfully verified, and encrypt the query result using the blinding point and the generated third random number to obtain the privacy data set.

2. The privacy query method for wireless body area networks according to claim 1, characterized in that, The trusted authorization center uses elliptic curve cryptography to obtain and publish public parameters, including: Using the elliptic curve cryptography described above, the prime order and the corresponding prime field and elliptic curve are obtained based on cryptographic security standards, and the additive cyclic group and generator corresponding to the prime order are generated. The system public key is obtained based on the generator and the system master private key; The common parameters are obtained based on the acquired general hash function and short hash function, as well as the additive cyclic group, the generator, the prime order corresponding to the additive cyclic group, and the system public key; The public parameters are disclosed to the user and the server.

3. The privacy query method for wireless body area networks according to claim 2, characterized in that, The server compiles a set of historical word lists based on the key hash values ​​corresponding to historical keywords, including: The server public key is obtained based on the randomly generated server private key and the generator; For historical keywords in the database, the short hash function is used to calculate the historical short hash value corresponding to each historical keyword; The historical keywords corresponding to the same historical short hash value are organized into a word list to generate the historical word list set.

4. The privacy query method for wireless body area networks according to claim 3, characterized in that, After system initialization, user registration is completed based on identity information and a trusted authorization center, including: Obtain the identity information and send the identity information and registration request to the trusted authorization center; The registration authentication parameters fed back by the trusted authorization center are verified according to the registration verification equation. The trusted authorization center is used to obtain the system registration public key based on the generated registration random number and the generator, generate the registration authentication parameters based on the public parameters, the system registration public key, the identity information and the registration random number, and feed back the system registration public key and the registration authentication parameters to the user. If verification is successful, the user information is obtained, including the identity information, the system registration public key, and the registration authentication parameters; if verification fails, the registration is terminated.

5. The privacy query method for wireless body area networks according to claim 4, characterized in that, The process of obtaining the target hash value of the target keyword and generating a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters includes: The target hash value of the target keyword is obtained using the short hash function. Using the general hash function, the original hash value is obtained by concatenating the identity information and the system registration public key into an identity string, and a temporary hash value is obtained based on the temporary fake identity; The blinding factor is obtained based on the temporary hash value and the original hash value.

6. The privacy query method for wireless body area networks according to claim 5, characterized in that, The process of performing blinding processing based on the generated first random number, second random number, the public parameter, the blinding factor, and the target hash value to obtain a blinding point, performing anonymous encryption processing on the temporary fake identity to obtain an anonymous signature, and making a data query request to the server includes: The blinding point is obtained based on the second random number, the generator, and the target hash value; The system registration public key and the registration authentication parameters are encrypted using the blinding factor to obtain the encrypted registration public key and encrypted registration parameters. Query parameters are obtained based on the first random number and the generator. Using the general hash function, an anonymous signature is generated based on the query parameters, the blinding point, the encrypted registration public key, and the encrypted registration parameters. An identity encryption ciphertext is generated based on the temporary fake identity and the first random number. The obtained query parameter set is then sent to the server to request a data query from the server. The query parameter set includes the encrypted registration public key, the blinding point, the identity encryption ciphertext, and the anonymous signature.

7. The privacy query method for wireless body area networks according to claim 6, characterized in that, The server is used to query the historical word list set based on the target hash value after successful verification of the anonymous signature, encrypt the query result using the blinding point and the generated third random number, and obtain the privacy data set, including: Verify the anonymous signature according to the query verification equation; If the verification is successful, retrieve the historical keywords in the historical word list set whose historical short hash values ​​are the same as the target hash value, and retrieve the report data corresponding to the historical keywords; The report data is encrypted using the blinding point, the generated third random number, and the generator to obtain the privacy data set.

8. The privacy query method for wireless body area networks according to claim 6, characterized in that, The step of generating encrypted identity ciphertext based on the temporary fake identity and the first random number includes: Using the general hash function, a query hash value is obtained based on the query string, wherein the system public key and the first random number are multiplied together and the target hash value and the blinding point to obtain the query string; The query hash value and the temporary fake identity are XORed bit by bit to obtain the encrypted identity ciphertext, which is used by the server for identity verification.

9. The privacy query method for wireless body area networks according to claim 8, characterized in that, The server is also used for: Decrypting the encrypted identity ciphertext yields the fake identity to be verified; Based on the fake identity to be verified, a parsed encrypted ciphertext is generated. The parsed encrypted ciphertext is used by the user to verify information before decrypting the privacy data set.

10. A privacy query device for wireless body area networks, characterized in that, include: An initialization module is used to complete user registration with the trusted authorization center based on the user's identity information after system initialization. The system initialization includes the trusted authorization center obtaining and publishing public parameters using elliptic curve cryptography, and the server organizing a set of historical word lists based on the key hash values ​​corresponding to historical keywords. The request module is used to obtain the target hash value of the target keyword, generate a blinding factor based on the generated temporary fake identity, the identity information, the system registration public key, and the public parameters, generate encryption parameters based on the blinding factor, perform blinding processing based on the generated first random number, second random number, the public parameters, the blinding factor, and the target hash value to obtain a blinding point, perform anonymous encryption processing on the temporary fake identity to obtain an anonymous signature, and send a data query request to the server. The query module is used to decrypt the privacy data set returned by the server based on the second random number and the target keyword to obtain a privacy query result. The server is used to query the historical word list set based on the target hash value after the anonymous signature is successfully verified, and encrypt the query result using the blinding point and the generated third random number to obtain the privacy data set.

Images