Certificateless linkable ring signcryption method and system based on SM2 algorithm

Abstract

The invention belongs to but is not limited to the technical field of privacy protection, and discloses a certificateless linkable ring signcryption method and system based on an SM2 algorithm, the adopted SM2 algorithm is a public key encryption algorithm based on an elliptic curve, the secret key length is shorter, the safety is higher, and the operation efficiency is remarkably improved in the encryption and decryption process. A certificateless public key cryptosystem is used, dependence on a traditional PKI system is not needed, and complexity and cost of certificate management are reduced. According to the invention, a linkable function is creatively added into a ring signcryption scheme and is applied to a remote medical information system. On the premise of ensuring the privacy of the patient, a doctor can retrieve the medical record of the patient through the signature tag generated by the patient, so that the illness state of the patient can be better known without knowing the specific identity of the patient. Compared with an existing scheme, the scheme is more suitable for remote medical seeing of the patient, and the practicability is higher.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the field of privacy protection technology, and in particular to a certificateless linkable ring signcryption method and system based on the SM2 algorithm. Background Art

[0002] Telemedicine Information System (TMIS) delivers medical services and information to geographically dispersed patients and medical staff through the Internet and other network technologies. These services can include diagnosis, treatment, monitoring, health education, etc. Telemedicine Information System is of great significance in improving the allocation of medical resources and improving the efficiency and quality of medical services.

[0003] In the existing telemedicine information system (TMIS), there are mainly the following problems:

[0004] (1) Insufficient protection of patient privacy and data security: Patient privacy and medical data security are one of the most important aspects of telemedicine service systems. Ensuring the security of patient privacy and medical data is not only related to the protection of personal privacy rights, but also directly affects patients' trust and acceptance of telemedicine services. The current existing privacy protection schemes have deficiencies in terms of indistinguishability and confidentiality, and patients' medical data are not safe under attacks by malicious key generation centers (KGCs).

[0005] (2) High communication and computing overhead: In telemedicine scenarios, a large amount of information interacts with medical servers. The communication and computing overhead of existing solutions is high, making it difficult to meet the growing telemedicine needs of patients.

[0006] (3) High certificate management cost: Most existing privacy protection schemes are based on public key infrastructure (PKI), which requires the management of a large number of certificates. This approach not only increases the management cost of the system, but also causes system performance degradation due to the maintenance of the certificate revocation list.

[0007] (4) Difficulty in consulting with doctors: Since telemedicine involves anonymous medical treatment for patients, doctors cannot retrieve the patient’s past medical records without knowing the patient’s identity, which invisibly increases the workload and difficulty of doctors’ consultations.

[0008] Ring Signcryption is a cryptographic scheme that combines ring signatures and encryption. It ensures data confidentiality, integrity, and authenticity while providing anonymity. Ring Signcryption is a cryptographic technique that combines ring signatures and encryption, allowing messages to be signed and encrypted anonymously. The signer selects multiple signers in a ring (group) and generates a signature, so that the verifier cannot determine the actual signer, but can confirm that the message does come from someone in the ring.

[0009] The SM2 algorithm is a public key cryptographic algorithm issued by the China National Cryptography Administration. It is based on elliptic curve cryptography (ECC) and is used for digital signatures, data encryption, and key exchange. The SM2 algorithm was officially incorporated into the national standard in 2010 and is widely used in China in the fields of finance, telecommunications, and government.

[0010] Compared with the traditional RSA algorithm, the SM2 algorithm is based on elliptic curve cryptography and has higher security and lower computational complexity.

[0011] The existing schemes for protecting patient privacy in telemedicine information systems include the anonymous authentication scheme for group medical consultation based on ring signatures by Lin et al., which proposed a new anonymous authentication scheme based on ring signatures. The scheme is designed for group medical consultation environments and can protect the privacy of doctors and patients at the same time. Compared with other schemes, this scheme takes less time and has more security features, such as the anonymity of doctors and patients. However, this scheme has great limitations in usage scenarios, and compared with the ring signature scheme based on elliptic curves, this scheme does not have an advantage in computational efficiency.

[0012] Disadvantages of existing technology:

[0013] (1) High certificate management cost: Most existing privacy protection schemes are based on public key infrastructure (PKI), which requires the management of a large number of certificates. This not only increases the management cost of the system, but also causes system performance degradation due to the maintenance of the certificate revocation list.

[0014] (2) High communication and computing overhead: Existing solutions have the problems of long key length and large amount of encryption and decryption algorithm operations, which leads to excessive communication and computing overhead, affecting the real-time and scalability of telemedicine information systems.

[0015] (3) Existing solutions have limited application scenarios: Currently, the largest application scenario of telemedicine information systems is remote medical treatment. Existing solutions are limited to group medical consultations and other aspects and cannot solve the problem of privacy protection for patients when seeking remote medical treatment. Summary of the invention

[0016] In view of the problems existing in the prior art, the present invention provides a certificateless linkable ring signcryption method and system based on the SM2 algorithm in a telemedicine information system.

[0017] The present invention is implemented in this way: a certificateless linkable ring signcryption method based on the SM2 algorithm comprises the following steps:

[0018] Step 1: The visiting patient interacts with KGC, KGC runs the setup algorithm, and discloses system information to the patient;

[0019] Step 2: The patient runs the SetSV algorithm to generate the user's partial private key and partial public key, and discloses the user's partial public key;

[0020] Step 3: After receiving the user's partial public key, KGC runs the ExtractPPK algorithm to find the partial public key and secret key value, and sends them to the patient through a public channel;

[0021] Step 4: The patient runs the generated PK algorithm, which first verifies the validity of the ciphertext value. If it is valid, it generates a public key and selects a designated doctor to run the signature encryption algorithm to generate the ciphertext and send it to the MS.

[0022] Step 5: MS sends the ciphertext to the designated doctor. After receiving the ciphertext, the doctor runs the verification and encryption algorithm to verify and decrypt the patient's medical information. If the ciphertext is valid, the doctor can save the medical data on the LS and use the signature tag in the ciphertext to run the link algorithm to retrieve the patient's past medical records locally. Finally, the diagnosis information will be returned to the MS for the patient to review.

[0023] Furthermore, in step 1, Setup(1 k )→(params,m sk ,P KGC ): KGC performs the setup process; the algorithm inputs the security parameter k and returns the system parameter params and the master public key P KGC .

[0024] Furthermore, in step 2, Set-SV(ID i )→(u i ,U i ): User input identifier ID i , and then output the user's U i and the secret value u i .

[0025] Further, in step 3, Extract-PPK(params,U i )→(d i ,X i): KGC passes input params and U i Run this algorithm and then for ID i Generate partial private key d i and X i .

[0026] Furthermore, in step 4, Generate-PK(d i ,X i )→(sk i ,PK i ): First verify d i Validity; then the user ID i By d i and u i Generate a pair of public and private keys and publish the public key PK i ;

[0027] RSigncryption(params,sk s ,PK r ,L,m)→(σ): User ID s Use parameters params,sk s ,PK r and L to sign the message m, and output the signature tag O s The ciphertext σ.

[0028] Furthermore, in step 5, Verification(params,L,σ)→(0,1): the verifier runs the verification algorithm. It takes the parameter params, the ring list L, and the ciphertext σ as input; if σ is valid, the algorithm outputs 1, otherwise it outputs 0;

[0029] Unsigncryption(params,L,σ)→(m): If the verification algorithm outputs 1, the verifier takes the parameters params, L and the ciphertext σ as input, runs the designcryption algorithm and outputs the message m; otherwise, the algorithm returns ⊥ and terminates;

[0030] Linking(σ)→(0,1): If the verification algorithm outputs 1, the verifier extracts the signature label O from the ciphertext σ s And compare with the local list to see if O exists s =O' s , if it exists, output 1, otherwise output 0.

[0031] Another object of the present invention is to provide a certificateless linkable ring signcryption system based on the SM2 algorithm, which is composed of five main entities: a key generation center KGC, a medical server MS, a patient, a doctor and a local server LS;

[0032] The key generation center KGC is a trusted third party that generates system parameters and master key pairs and generates signature private keys for patients;

[0033] Medical Server MS, a computer server used to store, manage and process medical data and applications, supporting applications such as electronic health records (EHR), hospital information systems (HIS), and picture archiving and communication systems (PACS);

[0034] The local server LS is used to store patient medical record information.

[0035] Another object of the present invention is to provide a computer device, the computer device comprising a memory and a processor, the memory storing a computer program, and when the computer program is executed by the processor, the processor executes the steps of the certificateless linkable ring signcryption method based on the SM2 algorithm.

[0036] Another object of the present invention is to provide a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the certificateless linkable ring signcryption method based on the SM2 algorithm.

[0037] Another object of the present invention is to provide an information data processing terminal, which includes the certificateless linkable ring signcryption system based on the SM2 algorithm.

[0038] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0039] First, the present invention proposes a certificateless linkable ring signcryption scheme based on SM2 in a telemedicine information system, which has:

[0040] (1) Enhanced privacy protection and data security: The certificateless ring signcryption scheme based on the SM2 algorithm is adopted to effectively enhance the indistinguishability of patient identity by utilizing the ring structure. The scheme ensures the confidentiality and integrity of medical information through ring signature technology. The ring signcryption scheme can prevent unauthorized access while ensuring data security, thus ensuring the protection of patient privacy. In addition, the scheme is efficient and scalable, and is suitable for the application of large-scale telemedicine information systems. Through this innovative design, medical service providers can ensure the security and reliability of data transmission while protecting patient privacy.

[0041] (2) Improve authentication efficiency and reduce computing overhead: The SM2 algorithm used is a public key encryption algorithm based on elliptic curves. It has a shorter key length and higher security, and significantly improves computing efficiency during the encryption and decryption process.

[0042] (3) Reduce certificate management costs: The use of a certificateless public key cryptography system eliminates the need to rely on the traditional PKI system, reducing the complexity and cost of certificate management.

[0043] (4) Adding linkability: Innovatively adding linkability to the ring signcryption scheme and applying it to TMIS, doctors can retrieve patients’ past medical records using the signature tags generated by patients without knowing their identities. This helps doctors better understand patients’ conditions while ensuring their privacy.

[0044] Second, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0045] (1) The expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0046] This patented technical solution innovatively applies the certificateless ring signcryption technology based on the SM2 algorithm to the Telemedicine Information System (TMIS). By utilizing the ring structure, the solution effectively enhances the indistinguishability of the patient's identity while ensuring the confidentiality and integrity of medical information.

[0047] Expected Returns:

[0048] 1. Improved data security: Through the encryption and signature technology of the national secret algorithm, medical data is highly protected during transmission and storage, preventing data leakage and tampering, and ensuring the confidentiality and integrity of the data. Certificateless identity authentication reduces the complexity and cost of certificate management, while preventing identity impersonation and fraud.

[0049] 2. Privacy protection: Ring signcryption technology ensures data confidentiality while providing anonymity and untraceability. Doctors can obtain necessary medical information without knowing the patient's true identity, thus protecting the patient's privacy.

[0050] 3. Reduced system management costs: The certificate-free solution reduces the reliance on certificates in the traditional PKI system, reduces the cost and complexity of certificate management and maintenance, and simplifies the system management process.

[0051] 4. Improve system credibility: The security guarantee based on the national secret algorithm makes the telemedicine information system more credible, enhances the trust of doctors and patients in the system, and helps to improve the quality of telemedicine services and user satisfaction.

[0052] 5. Compliance and market acceptance: The use of national cryptographic algorithms complies with relevant standards and regulations of China's national cryptographic management, ensures the compliance of the telemedicine information system, facilitates its promotion and application in the domestic market, and meets policy and regulatory requirements.

[0053] Commercial value:

[0054] 1. Enhanced market competitiveness: Telemedicine information systems with high security and privacy protection are more competitive in the market, attracting more hospitals and medical institutions to adopt them, thereby expanding market share.

[0055] 2. Expand the user base: By providing safe and reliable telemedicine services, we can increase the trust and satisfaction of patients and doctors, attract more users to join the platform, expand the user base, and increase market share.

[0056] 3. Significant cost-effectiveness: Reducing the cost of certificate management and maintenance makes system operation more efficient, reduces operating costs, and improves the cost-effectiveness of the system.

[0057] 4. Innovation-driven development: The telemedicine information system based on this patented technical solution is innovative and can promote the company's technological leadership in the industry, enhance the company's innovation drive, and promote the company's sustainable development.

[0058] 5. Long-term development potential: This technical solution is efficient and scalable, can meet the needs of large-scale telemedicine systems, has good scalability and adaptability, and provides strong guarantees for the long-term development of the enterprise.

[0059] Through the transformation and application of this patented technical solution, enterprises can not only enhance their own market competitiveness and user satisfaction, but also reduce operating costs, improve the cost-effectiveness and long-term development potential of the system, and lay a solid foundation for the sustainable development of enterprises in the field of telemedicine.

[0060] (2) The technical solution of the present invention fills the technical gap in the industry at home and abroad:

[0061] 1. Innovative combination of national secret algorithm: This invention combines the national secret algorithm with the telemedicine information system for the first time, and uses the certificateless ring signcryption technology based on the SM2 algorithm to effectively improve the security and privacy protection level of the system. Compared with the traditional PKI system, this invention provides the same or even higher security in a certificateless environment, solving the complexity of certificate management.

[0062] 2. Enhanced patient privacy protection: Through the ring signcryption technology, the present invention has reached a new level in protecting patient privacy. Doctors can retrieve the patient's historical medical records through the signature tag without knowing the patient's true identity, which has never been achieved in the prior art.

[0063] 3. Reduce system management costs: The introduction of the certificate-free solution greatly reduces the need for certificate management and maintenance, and reduces the operating cost and complexity of the system. Compared with the existing PKI-based system, the present invention is more economical and operational.

[0064] 4. Improve system credibility and compliance: The national secret algorithm adopted by the present invention complies with the relevant standards and regulations of national password management, ensuring the compliance of the system. This makes it easier for the telemedicine information system to be recognized and promoted in the domestic market.

[0065] 5. Efficiency and scalability: The technical solution designed in the present invention has efficient computing performance and good scalability, can adapt to the needs of large-scale telemedicine systems, and provides technical support for the popularization and development of telemedicine services.

[0066] 6. Anti-quantum computing threats: The national secret algorithm took into account the potential threats of quantum computing when it was designed, and has a certain ability to resist quantum computing attacks, providing forward-looking protection for future information security.

[0067] The invention is not only innovative and groundbreaking in theory, but also has significant economic benefits and social value in practical applications, injecting new impetus and direction into the development of telemedicine information systems at home and abroad. Through the promotion and application of the invention, telemedicine services will be safer, more efficient and reliable, further improving the quality and coverage of medical services.

[0068] Fourth, the present invention proposes a certificateless linkable ring signcryption method and system based on the SM2 algorithm, which is mainly used in the field of medical information security to ensure the privacy, integrity and traceability of patient information. Through the certificateless linkable ring signature technology, efficient encryption and signing of medical data is achieved, while ensuring the verifiability and linkability of the data, which is convenient for doctors to trace and review the patient's historical medical records while protecting the patient's privacy.

[0069] The technical solution of the present invention not only solves the security risks existing in traditional medical information systems, but also improves the processing efficiency and security of medical data through certificateless linkable ring signcryption technology. In addition, the system consists of five main entities: KGC, MS, patient, doctor and LS. The entities communicate with each other through a secure encryption and signature mechanism, ensuring the reliability and robustness of the entire medical information system.

[0070] In summary, the present invention realizes the secure transmission, storage and retrieval of medical data through a certificateless linkable ring signcryption method based on the SM2 algorithm, providing an efficient and secure solution for modern medical information systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 It is a flow chart of a certificateless linkable ring signcryption method based on the SM2 algorithm provided by an embodiment of the present invention;

[0072] Figure 2It is a structure diagram of a certificateless linkable ring signcryption system based on the SM2 algorithm provided by an embodiment of the present invention;

[0073] Figure 3 This is a time comparison effect diagram of the Ring Signcryption algorithm based on the SM2 algorithm provided in an embodiment of the present invention;

[0074] Figure 4 It is a time comparison effect diagram of the Unigncryption algorithm based on the SM2 algorithm provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0075] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0076] The certificateless linkable ring signcryption method based on the SM2 algorithm has significant advantages and application potential in multiple industrial applications. The following are two specific industrial application examples:

[0077] Example 1: Telemedicine System

[0078] In telemedicine systems, patients communicate and diagnose with doctors through the Internet. This method greatly facilitates patients, especially those who live in remote areas or have limited mobility. However, how to ensure the secure transmission and storage of patients' medical records and personal privacy is an urgent problem to be solved.

[0079] Application Process:

[0080] 1. Patient identity registration and key generation: Patients interact with the key generation center KGC through visiting patients. KGC generates system parameters and discloses them to patients. Patients run the SetSV algorithm to generate partial private keys and partial public keys, and disclose partial public keys.

[0081] 2. Partial public key extraction and public key generation: KGC runs the ExtractPPK algorithm to extract the patient's partial public key and generate a partial private key, which is then sent to the patient through a public channel. After the patient verifies the validity of the key, the GeneratePK algorithm is run to generate a complete public-private key pair.

[0082] 3. Data encryption and transmission: The patient selects a designated doctor and uses a signature encryption algorithm to sign the medical record data, generate ciphertext and send it to the medical server MS. MS forwards the ciphertext to the designated doctor.

[0083] 4. Data verification and decryption: After receiving the ciphertext, the doctor runs the verification and decryption algorithm to verify the validity of the ciphertext and decrypt the medical record data. If the verification is successful, the doctor saves the data in the local server LS and uses the signature tag to retrieve the patient's past medical record information for association analysis.

[0084] 5. Return of diagnosis results: After the doctor completes the diagnosis, the results will be returned to the medical server MS for the patient to review.

[0085] Advantages: Ensure the security and privacy of patient medical records during transmission and storage. Improve the system's anti-attack capabilities and prevent data tampering and identity forgery. Achieve secure association of medical record data, making it easier for doctors to conduct comprehensive analysis of historical medical records.

[0086] Example 2: Intelligent medical equipment interconnection system

[0087] In the interconnected system of smart medical devices, various smart medical devices (such as electrocardiographs, blood pressure monitors, thermometers, etc.) need to collect patient data in real time and transmit it to the central server for storage and analysis. How to ensure the security of data during transmission and prevent the device identity from being forged is an important challenge.

[0088] Application Process:

[0089] 1. Device registration and key generation: Smart medical devices interact with the key generation center KGC, which generates system parameters and makes them public to the device. The device runs the SetSV algorithm to generate partial private keys and partial public keys, and makes partial public keys public.

[0090] 2. Extraction of partial public keys and generation of public keys: KGC runs the ExtractPPK algorithm to extract part of the device's public key and generate part of the private key, which is then sent to the device through a public channel. After the device verifies the validity of the key, it runs the GeneratePK algorithm to generate a complete public-private key pair.

[0091] 3. Data encryption and transmission: After collecting patient data, the device uses a signature encryption algorithm to sign the data, generate ciphertext and send it to the central medical server MS.

[0092] 4. Data verification and decryption: After receiving the ciphertext, the central medical server runs the verification and decryption algorithm to verify the validity of the ciphertext and decrypt the device data. If the verification is successful, the server stores and analyzes the data and generates a patient health report.

[0093] 5. Device data association: The central server uses signature tags to perform association analysis on device data to ensure the legitimacy of the data source, and returns the analysis results to the relevant medical devices and doctors for further diagnosis.

[0094] Advantages: Ensure the security and privacy of smart medical device data during transmission and storage. Prevent device identity forgery and ensure the credibility of data sources. Achieve secure association of multi-device data for comprehensive analysis and diagnosis.

[0095] Through the above two embodiments, it can be seen that the certificateless linkable ring signcryption method based on the SM2 algorithm has significant advantages in ensuring data security and privacy, improving the system's anti-attack capabilities, and realizing data security association. It can be widely used in the fields of telemedicine and intelligent medical device interconnection.

[0096] like Figure 1 As shown, the certificateless linkable ring signcryption method based on the SM2 algorithm provided in an embodiment of the present invention includes the following steps:

[0097] Step 1: The visiting patient interacts with KGC, KGC runs the setup algorithm, and discloses system information to the patient;

[0098] Step 2: The patient runs the SetSV algorithm to generate the user's partial private key and partial public key, and discloses the user's partial public key;

[0099] Step 3: After receiving the user's partial public key, KGC runs the ExtractPPK algorithm to find the partial public key and secret key value, and sends them to the patient through a public channel;

[0100] Step 4: The patient runs the generated PK algorithm, which first verifies the validity of the ciphertext value. If it is valid, it generates a public key and selects a designated doctor to run the signature encryption algorithm to generate the ciphertext and send it to the MS.

[0101] Step 5: MS sends the ciphertext to the designated doctor. After receiving the ciphertext, the doctor runs the verification and encryption algorithm to verify and decrypt the patient's medical information. If the ciphertext is valid, the doctor can save the medical data on the LS and use the signature tag in the ciphertext to run the link algorithm to retrieve the patient's past medical records locally. Finally, the diagnosis information will be returned to the MS for the patient to review.

[0102] The certificateless linkable ring signcryption method based on the SM2 algorithm consists of the following eight algorithms and is implemented by the following three entities: KGC, ID s ,ID r .

[0103] (1)Setup(1 k )→(params,m sk ,P KGC ): KGC performs the setup process. The algorithm inputs the security parameter k and returns the system parameter params and the master public key P KGC .

[0104] (2) Set-SV(ID i )→(u i ,U i ): User input identifier ID i , and then output the user's U i and the secret value u i .

[0105] (3) Extract-PPK(params,U i )→(d i ,X i ): KGC passes input params and U i Run this algorithm and then for ID i Generate partial private key d i and X i .

[0106] (4)Generate-PK(d i ,X i )→(sk i ,PK i ): First verify d i The user ID i By d i and u i Generate a pair of public and private keys and publish the public key PK i .

[0107] (5)RSigncryption(params,sk s ,PK r ,L,m)→(σ): User ID s Use parameters params,sk s ,PK r and L to sign the message m, and output the signature tag O s The ciphertext σ.

[0108] (6) Verification(params,L,σ)→(0,1): The verifier runs the verification algorithm. It takes the parameter params, the ring list L, and the ciphertext σ as input. If σ is valid, the algorithm outputs 1, otherwise it outputs 0.

[0109] (7)Unsigncryption(params,L,σ)→(m): If the verification algorithm outputs 1, the verifier takes the parameters params, L and the ciphertext σ as input, runs the designcryption algorithm and outputs the message m.

[0110] Otherwise, the algorithm returns ⊥ and terminates.

[0111] (8) Linking(σ)→(0,1): If the verification algorithm outputs 1, the verifier extracts the signature label O from the ciphertext σ s And compare with the local list to see if O exists s =O' s , if it exists, output 1, otherwise output 0.

[0112] The certificateless linkable ring signcryption method based on the SM2 algorithm provided in the embodiment of the present invention is specifically as follows:

[0113] 1. Setup: Enter a security parameter k, and KGC runs the following algorithm:

[0114] (a) KGC s selects two large prime numbers p, q>2 k ,F p is a finite field. Elliptic curve function E:y 2 =x 3 +ax+bmodp is defined in F p on. The points satisfying the equation form an Abelian groupG1 of order q,G is the generator of G1.

[0115] (b) KGC randomly selects s Setting m sk =π and calculate the system master public key P KGC =[π]·G.

[0116] (c) KGC sets five secure hash functions H0, H1, H2, H3, H4, H2=G1×G1→{0,1} l , l is the length of the message.

[0117] (d) KGC sets the system parameters params = {p, q, E / F P ,G1,P KGC ,G,H0,H1,H2,H3,H4} are open to all users.

[0118] 2.SetSV:UserID i Random Selection And calculate U i =[u i ] G is the user's partial public key and publishes U i .

[0119] 3.ExtractPPK: When receiving U i After that, KGC randomly selects And calculate X i =[x i ]·G,w i =H1(ID i ,X i ,U i ,P KGC ), d i =(x i +w i ·π+H0(πU i ))mod q,d i is a partial private key. Subsequently, KGC will (d i ,X i ) using the public channel to send to ID i .

[0120] 4.GeneratePK: When the user receives (d i ,X i ), first calculate k i =d i -H0(u i P KGC ) mod q, then calculate ω i =H1(ID i ,X i ,U i ,P KGC ) and verify whether d i G = X i +w i ·P KGC .

[0121] If the verification result passes, generate the private key sk i =(u i +d i )=(u i +x i +w i π) mod q and public key PK i =sk i G=U i +X i +w i ·P KGC .

[0122] Otherwise, the user ID i Send a private key query to KGC again.

[0123] 5.Signcryption: Assume {ID1,ID2,...,ID n} is a set of ring memberships, L = {PK1,PK2...,PK n} is the ring public key. ID s is a real signer, running the following algorithm:

[0124] (a) Calculate the signature tag O s :R=H4(L),O s =sk s ·R.

[0125] (b) Random selection Then calculate C1 = [θ]·G, Q = [θ]·PK r , in It is an XOR operation.

[0126] (c) Random selection Calculate v s+1 =H3(L,O s ,m,k s (G+R)), for i=s+1,...n,1,...,s-1, perform the following operations: randomly generate Calculate Z i =a i ·(G+R)+(a i +v i )·(RK i +O s ), and v i+1 =H3(L,O s ,m,Z i )When v1=v n+1 hour.

[0127] (d) When i = s, calculate a s =((1+sk s ) -1 ·(k s -v s ·sk s ))mod q.

[0128] (e) Add the timestamp TS to the ciphertext and send the ciphertext σ = (a1, a2, ..., a n ,C1,C2,v1,L,O s ,TS).

[0129] 6.Verification and Usigncryption: When ID r After receiving the ciphertext σ, first use the formula |TS'-TS cur |<Δ TSConfirm whether the timestamp TS is valid, Δ TS is the maximum valid time interval set by the system. If it is invalid, the ciphertext will be discarded. Otherwise, run the following steps:

[0130] (a) Verify whether If yes, run the following steps, otherwise the verification fails.

[0131] (b) ID r Calculate Q' = sk r ·C'1,

[0132] (c) First calculate R = H5(L), then calculate Z' for i = 1, 2, ..., n i =a' i ·(G+R)+(a' i +v' i )·(PK i +O' s ),v' i =H4(L,O' s ,m',Z' i ).

[0133] (d) Recipient ID r Check v'1 = v' n+1 Is it true? If yes, ID r Confirm that the ciphertext σ is valid and accept it. Otherwise, discard the ciphertext.

[0134] 7.Linking: Given a ciphertext (a'1,...,a' n ,C'1,...,O' s ,TS'), input the ciphertext into the verification algorithm, if it passes the verification and outputs the plaintext, we get O' s , and then compare it with the local data to see if O" s =O' s , thereby obtaining the patient's past medical records data stored on the local server.

[0135] like Figure 2 As shown, the certificateless linkable ring signcryption method based on the SM2 algorithm and the certificateless linkable ring signcryption system based on the SM2 algorithm provided by an embodiment of the present invention are composed of five main entities: a key generation center KGC, a medical server MS, a patient, a doctor and a local server LS.

[0136] (1) Key Generation Center KGC: KGC is a trusted third party. It is responsible for generating system parameters and master key pairs, and generating signature private keys for patients.

[0137] (2) Medical Servers: Medical servers are computer servers used to store, manage, and process medical data and applications. They play a core role in the information systems of medical institutions, supporting applications such as electronic health records (EHR), hospital information systems (HIS), and picture archiving and communication systems (PACS).

[0138] (3) Local server LS: The local server is used to store patient medical record information.

[0139] The embodiment of the present invention selects existing excellent literature that solves similar problems, and compares them mainly from the two aspects of security and computational cost. The simulation experiment configuration: window11 and 64-bit operating system, Ryzen75800H processor CPU3.20GHz, 32G memory. In addition, in order to analyze the efficiency of the scheme, we called the JPBC cryptographic library in the JDK8 operating environment under Widnows11 to operate the scheme. Table 2 lists the time consumption of the four main operations. In order to facilitate the comparison of different algorithms and provide more convincing results, we set the security level to 80 bytes.

[0140] To simplify the comparison process, we only selected the signature encryption and non-signature encryption algorithms with the highest computational cost among these schemes. Figure 3 and Figure 4 The trends of computational costs of signature encryption and non-signature encryption algorithms as a function of n are shown respectively. Then, we compare them in terms of scheme characteristics such as indistinguishability, unforgeability, unconditional anonymity, and linkability, as shown in Table 5. From the various charts above, we can clearly see that CLLRSC has the lowest computational cost in these two key stages, while our scheme provides more functionality and security.

[0141] Table 5 Comparison of security features of various solutions

[0142]

[0143] Literature

[32] S. Zhang, J. Rong, B. Wang, "A privacy protection scheme of smartmeter for decentralized smart home environment based on consortium blockchain", International Journal of Electrical Power and Energy Systems, vol. 121, p. 106140, 2020.

[0144] Literature

[33] VKYadav, N.Andola, S.Verma, et al, "Anonymous and linkablelocationbased services", IEEE Transactions on Vehicular Technology, vol.71, no.9, pp.93979409, 2022.

[0145] Literature

[34] H. Yu, J. Liu, Z. Wang, et al, "Certificateless ring signcryption for multisource network coding", Computer Standards and Interfaces, vol.81, p.103602, 2022.

[0146] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. A person of ordinary skill in the art will appreciate that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVDROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0147] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A certificateless linkable ring signcryption method based on SM2 algorithm, characterized in that: The following steps are involved: Step 1: The visiting patient interacts with the key generation center KGC, which runs the setup algorithm and discloses system information to the patient; Step 2: The patient runs the SetSV algorithm to generate the user's partial private key and partial public key, and discloses the user's partial public key; Step 3: After receiving the user's partial public key, KGC runs the ExtractPPK algorithm to find the partial public key and secret key value, and sends them to the patient through a public channel; Step 4: The patient runs the generated PK algorithm, which first verifies the validity of the ciphertext value. If it is valid, it generates a public key and selects a designated doctor to run the signature encryption algorithm to generate the ciphertext and send it to the medical server MS. Step 5: MS sends the ciphertext to the designated doctor; after receiving the ciphertext, the doctor runs the verification and encryption algorithm to verify and decrypt the patient's medical information; If the ciphertext is valid, the doctor can save the medical data on the local server LS and use the signature tag in the ciphertext to run the link algorithm to retrieve the patient's past medical records locally; finally, the diagnosis information will be returned to MS for the patient to review.

2. The certificateless linkable ring signcryption method based on the SM2 algorithm as claimed in claim 1, characterized in that: In step 1, Setup(1 k )→(params, m sk , P KGC ): KGC performs the setup process; the algorithm inputs the security parameter k and returns the system parameter params and the master public key P KGC .

3. The certificateless linkable ring signcryption method based on the SM2 algorithm as claimed in claim 1, characterized in that: In step 2, Set-SV(ID i )→(u i , U i ): User input identifier ID i , and then output the user's U i and the secret value u i .

4. The certificateless linkable ring signcryption method based on the SM2 algorithm as claimed in claim 1, characterized in that: In step 3, Extract-PPK(params, U i )→(d i , X i ): KGC passes input params and U i Run this algorithm and then for ID i Generate partial private key d i and X i .

5. The certificateless linkable ring signcryption method based on the SM2 algorithm as claimed in claim 1, characterized in that: In step 4, Generate-PK(d i , X i )→(Sk i , PK i ): First verify d i Validity; then the user ID i By d i and u i Generate a pair of public and private keys and publish the public key PK i ; RSigncryption(params, sk s , PK r , L, m)→(σ): User ID s Use the parameters params, sk s , PK r and L to sign the message m, and output the signature tag O s The ciphertext σ.

6. The certificateless linkable ring signcryption method based on the SM2 algorithm as claimed in claim 1, characterized in that: In step 5, Verification(params, L, σ)→(0, 1): the verifier runs the verification algorithm. It takes the parameter params, the ring list L, and the ciphertext σ as input; if σ is valid, the algorithm outputs 1, otherwise it outputs 0; Unsigncryption(params, L, σ)→(m): If the verification algorithm outputs 1, the verifier takes the parameters params, L and the ciphertext σ as input, runs the decryption algorithm and outputs the message m; otherwise, the algorithm returns ⊥ and terminates. Linking(σ)→(0, 1): If the verification algorithm outputs 1, the verifier extracts the signature label O from the ciphertext σ s And compare with the local list to see if O exists s =O′ s , if it exists, output 1, otherwise output 0.

7. The certificateless linkable ring signcryption system based on the SM2 algorithm and the certificateless linkable ring signcryption method based on the SM2 algorithm according to any one of claims 1 to 6, characterized in that: It consists of five main entities: key generation center KGC, medical server MS, patients, doctors and local server LS; The key generation center KGC is used to generate system parameters and master key pairs, and generate signature private keys for patients; Medical server MS, a computer server used to store, manage and process medical data and applications, supporting electronic health records EHR, hospital information system HIS, and image archiving and communication system PACS; The local server LS is used to store patient medical record information.

8. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the certificateless linkable ring signcryption method based on the SM2 algorithm as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the certificateless linkable ring signcryption method based on the SM2 algorithm as claimed in any one of claims 1 to 6.

10. An information data processing terminal, characterized in that: The information data processing terminal includes the certificateless linkable ring signcryption system based on the SM2 algorithm as described in claim 7.

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