Blockchain-based electronic immunity passport supervision method

Abstract

The present invention provides a blockchain-based electronic immunization passport supervision method, which generates and distributes public and private key pairs through a certificate authority CA; hospital h generates an immunization passport m for vaccine recipient i and assigns a passport number PUID i ; Hospital h for immunity passport m and passport number PUID i Encryption; Hospital h generates transaction T C And upload it to the national alliance chain node; the national alliance chain node generates transaction T W And upload it to the World Alliance Chain; when the vaccine recipient i is asked to view the immunity passport m, he / she provides the passport number PUID i , generating a trapdoor T Q And upload to the World Alliance Chain; the World Alliance Chain receives the trapdoor T Q After that, the ciphertext C of the immunity passport m is 1 Sent to vaccine recipient i; vaccine recipient i receives ciphertext C 1 After that, the immune passport document data m is obtained by decryption; the alliance chain nodes are regularly maintained by using smart contracts; the present invention can ensure the publicity, traceability and non-tamperability of the data, can realize effective supervision of the immune passport data, can provide reliable immune passport data, and can realize the search and regular maintenance of the immune passport.

Description

Technical Field

[0001] The present invention proposes a blockchain-based electronic immunity passport supervision method, which involves technical fields such as blockchain, consensus algorithm, and data security protection. Background Art

[0002] In order to restore and develop the economy, ease people's living pressure, and resume normal production, life, and international exchanges, countries and regions have proposed issuing immunity passports.

[0003] However, there are some problems with immunity passports. Due to the differences between different types of vaccines, different vaccination methods in different countries, the time intervals between multiple doses of vaccines and other factors, different countries have disagreements on the reliability of immunity passports, which increases the difficulty of unified management.

[0004] On the other hand, it is also necessary to determine the minimum length of immunity after vaccination and monitor its duration to understand whether and when passport holders need to reassess their immunity status and renew their passports. At the same time, immunity passports also have the problem of forgery and privacy leakage of personal information data.

[0005] The above issues are those that should be considered and addressed in the design and use of immunity passports. Summary of the invention

[0006] The present invention proposes a blockchain-based electronic immunity passport supervision method, which uses blockchain technology and searchable encryption technology to solve problems such as the non-sharing of immunity passport data and the need to ensure reliability, and realizes the mutual recognition and interoperability of immunity passports of various countries, so as to promote the gradual resumption of international exchanges and international economic and trade activities.

[0007] A blockchain-based electronic immunity passport supervision method includes the following steps:

[0008] S1. The certificate authority CA initializes the public parameter CP according to the security parameters, generates and distributes the public and private key pairs for each member in the blockchain system, including the vaccine recipient i, the hospital h, the national alliance chain node c and the world alliance chain node w;

[0009] S2. After the vaccine recipient i is vaccinated in hospital h, hospital h generates an immunity passport m for the vaccine recipient i and assigns a passport number PUID i ;

[0010] S3, hospital h for immunity passport m and passport number PUID i Encryption is performed, and a hash value H1(C1) of the ciphertext C1 of the immunity passport m is generated, and the ciphertext C1 of the immunity passport m is uploaded to the hospital server for storage;

[0011] S4, hospital h uses the ciphertext hash value H1(C1), keyword index I K Generate transaction T with the validity period T of the immunity passport C , and trade T C Upload to the national alliance chain node;

[0012] S5. National alliance chain nodes use searchable encryption technology to build a secure index I S , using the security index I S and validity period T to generate transaction T W And trade T W Upload to the World Alliance Chain;

[0013] S6. When the vaccine recipient i is asked to view the immunity passport m, the vaccine recipient i uses searchable encryption technology to find the passport number PUID. i Generate Trapdoor T Q , and the trapdoor T Q Uploaded to the World Alliance Chain as a transaction;

[0014] S7, World Alliance Link receives Trapdoor T Q After that, the smart contract is used to search for the ciphertext C1 of the corresponding immunity passport m. After finding it, the ciphertext C1 of the immunity passport m is sent to the vaccine recipient i;

[0015] S8, after receiving the immunization passport ciphertext C1, the vaccine recipient i decrypts it and obtains the immunization passport ciphertext data m for viewing;

[0016] S9. Alliance chain nodes, including national alliance chain nodes and world alliance chain nodes, use smart contracts for regular maintenance to check whether the immunity passport m is expired and update the expired immunity passport m.

[0017] Further, step S1 is specifically,

[0018] S11. According to the input security parameter λ, the certificate authority CA selects two multiplicative cyclic groups G1 and G2 with order p as prime number, generates element g∈G1, defines bilinear mapping e: G1×G1→G2, and takes three anti-collision hash functions H2: {0, 1} * →G1,H3:G2→{0,1} * , publish public parameters CP = {p, g, e, H1, H2, H3};

[0019] S12. Random selection of certificate authority CA As the private key sk of vaccine recipient i i , calculate its public key Random Selection As the private key sk of hospital h h, calculate its public key Random Selection As the private key sk of the national alliance chain node c c , calculate its public key Random Selection As the private key sk of the world alliance chain node w w , calculate its public key

[0020] S13. The certificate authority CA distributes the public and private key pairs obtained in step S12 to each member of the blockchain system including the vaccine recipient i, hospital h, national alliance chain node c and world alliance chain node w through a secure channel.

[0021] Furthermore, in step S2, the immunity passport m includes the user's personal information and vaccination information, and the vaccination information includes the vaccination time, vaccination location and vaccine information.

[0022] Further, in step S3, hospital h compares the immunity passport m and the passport number PUID i Encryption is performed, specifically, hospital h randomly selects a secret value in, is the remainder class of integers modulo p, that is calculate k=e(g θ , H2(PUID i )), B = k × m, F = H3 (k), where pk i is the public key of vaccine recipient i, e is the bilinear mapping defined in step S11, g is the generator of G1, G1 is a multiplicative cyclic group whose order is a prime number p, H2 and H3 are two collision-resistant hash functions, m is the plaintext data of the immunity passport, and C1 = (A, B) is the ciphertext of the immunity passport m, and C2 = (A, F) is the immunity passport number PUID i The ciphertext.

[0023] Further, in step S4, hospital h uses the ciphertext hash value H1(C1) and the keyword index I K Generate transaction T with the validity period T of the immunity passport C , and trade T C Upload to the national alliance chain node, specifically,

[0024] S41, hospital h uses searchable encryption technology to identify the PUID of the immune passport i The ciphertext C2 constructs the keyword index I K = <c2>;

[0025] S42, hospital h uses the hash value H1(C1) of the ciphertext of the immunity passport m, the validity period T of the immunity passport and the keyword index I K Generate transaction T C ;

[0026] S43, Hospital h will trade T C The package is uploaded to the national alliance chain node, and the national alliance chain node runs the PBFT consensus mechanism to check the transaction T C Verify, and after successful verification, the national alliance chain node generates a new block C .

[0027] Furthermore, in step S5, the national alliance chain node uses searchable encryption technology to construct a security index I S , using the security index I S and validity period T to generate transaction T W And trade T W Upload to the World Alliance Chain, specifically,

[0028] S51. In each national alliance chain, the national alliance chain node extracts the keyword index I in each transaction in the block Blockc generated in step S43. K , validity period T and block identifier BID of the alliance chain of the country;

[0029] S52, using keyword index I K Construct security index I with national alliance chain block identifier BID S = <BID,I K >

[0030] S53, National Alliance Chain Node Utilization Security Index I S and validity period T to generate transaction T W ;

[0031] S54, the national alliance chain node will trade T W The package is uploaded to the World Alliance Chain. The World Alliance Chain nodes run the PBFT consensus mechanism to verify the transaction. After the verification is successful, the World Alliance Chain generates a new block. W .

[0032] Further, in step S6, when the vaccine recipient i is asked to view the immunity passport m, the vaccine recipient i uses searchable encryption technology to obtain the passport number PUID m. i Generate Trapdoor T Q , and the trapdoor T Q Uploaded to the World Alliance Chain as a transaction, specifically,

[0033] S61. When the vaccine recipient i is asked to view the immunity passport m, the vaccine recipient i randomly selects a secret value in, Use your passport number PUID i ,calculate τ2=g d , where sk i is the private key of vaccine recipient i, pk w is the public key of the world alliance chain node w, H2 is the hash function defined in step S11, and g is the generator of G1;

[0034] S62, Generate Trapdoor T Q = <τ1, τ2>, where τ1 and τ2 are the parameters calculated in step S61, and the trapdoor T Q Uploaded to the World Alliance Chain as a transaction.

[0035] Further, in step S7, the world alliance link receives the trapdoor T Q After that, the smart contract is used to search for the ciphertext C1 of the corresponding immunity passport m. After finding it, the ciphertext C1 of the immunity passport m is sent to the vaccine recipient i. Specifically,

[0036] S71, the world alliance chain node receives the trapdoor T Q = <τ1, τ2>, calculate Among them, sk w is the private key of the world alliance chain node w, and τ2 = g d is the parameter calculated in step S61;

[0037] S72, the block generated by the world alliance chain node in step S54 W Extract transaction T W Security Index I S = <BID,I K >, verify the equation Is it established? Where BID is the national alliance chain block identifier, I K = <c2>is the keyword index, C2=(A, F) is the immunity passport number PUID i The ciphertext, and F = H3(k) are the parameters calculated in step S3, k = e(g θ , H2(PUID i )),sk w is the private key of the world alliance chain node w, τ1 and τ2 are the parameters calculated in step S61, and e is the bilinear mapping defined in step S11; if it holds, then the transaction T is extracted W The national ID and national alliance chain block identifier BID;

[0038] S73. Find the corresponding national alliance chain according to the national ID;

[0039] S74. In the national alliance chain, access the corresponding block through the national alliance chain block identifier BID;

[0040] S75, extracting the hash value H1(C1) of the ciphertext C1 of the immunity passport m in the block and the hospital ID;

[0041] S76, using the hospital ID to find the corresponding hospital server, and after comparing the hash values, obtain the ciphertext C1=(A, B) of the immunity passport m;

[0042] S77, returning the ciphertext C1 of the immunity passport m to the alliance chain node;

[0043] S78. The alliance chain node sends the ciphertext C1 of the immunity passport m to the vaccine recipient.

[0044] Further, in step S8, the vaccine recipient i receives the immunization passport ciphertext C1 and decrypts it to obtain the immunization passport ciphertext data m, which is specifically,

[0045] S81. Vaccine recipient i receives the ciphertext C1=(A, B) of immunity passport m, where and B = k × m are the parameters calculated in step s3, k = e(g θ , H2(PUID i ));

[0046] S82. Calculate immune protection document data Among them, sk i is the private key of vaccinee i, and H2 is the hash function defined in step S11.

[0047] Further, in step S9, the alliance chain nodes including the national alliance chain nodes and the world alliance chain nodes use smart contracts for regular maintenance to check whether the immunity passport m is expired, and update the expired immunity passport m, specifically,

[0048] S91. The alliance chain node obtains the validity period T of the immunity passport m in the transaction;

[0049] S92, the alliance chain node obtains the timestamp t of the transaction;

[0050] S93. Alliance chain node obtains current time T cur ;

[0051] S94. Calculate T cur -t, if T cur -t≤T, it means that the current immunity passport m has not expired; if T cur -t>T, indicating that the current immunity passport m has expired. The relevant hospital is notified through the national alliance chain node to re-evaluate the immunity status of the vaccine recipient i and update the immunity passport for him.

[0052] The beneficial effects of the present invention are:

[0053] 1. This blockchain-based electronic immunity passport supervision method uses blockchain technology to save relevant data such as indexes and the validity period of immunity passports, ensuring the openness, traceability, and non-tamperability of data. It can effectively supervise immunity passport data, provide reliable immunity passport data for vaccine recipients, and facilitate the mutual recognition and interoperability of immunity passports in various countries, providing convenience for vaccine recipients. It avoids the problem of immunity passport data being forged and the privacy leakage of personal information data. The search and regular maintenance of immunity passports are completed using blockchain smart contracts.

[0054] 2. This blockchain-based electronic immunity passport supervision method ensures the confidentiality of data through searchable encryption technology, realizes the sharing of immunity passport data, and combines cryptography technology to solve the problems of privacy leakage and forgery of personal information data.

[0055] 3. To address the issue of the validity period of vaccines and immunity passports, the present invention utilizes technologies such as smart contracts and timestamps to supervise transactions on the alliance chain and detect the validity period of immunity passports in order to understand whether and when immunity passport holders need to re-evaluate their immunity status and update their passports.

[0056] 4. This blockchain-based electronic immunity passport supervision method records the user's personal information and vaccination information in the immunity passport. The immunity passport is conducive to the resumption of normal production and life, international exchanges and international economic and trade activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a flowchart of the blockchain-based electronic immunity passport supervision method of an embodiment of the present invention.

[0058] Figure 2 It is a schematic diagram for explaining the blockchain system in the embodiment.

[0059] Figure 3 Schematic diagram of the immunity passport in the embodiment.

[0060] Figure 4 In the embodiment, transaction T C Schematic diagram of the structure.

[0061] Figure 5 In the embodiment, transaction T W Schematic diagram of the structure. DETAILED DESCRIPTION

[0062] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0063] Example

[0064] A blockchain-based electronic immunity passport supervision method, such as Figure 1 and Figure 2 , including the following steps,

[0065] S1. The certificate authority CA initializes the public parameter CP according to the security parameter, generates and distributes the public and private key pairs for each member in the blockchain system, including the vaccine recipient i, the hospital h, the national alliance chain node c and the world alliance chain node w; Step S1, specifically,

[0066] S11. According to the input security parameter λ, the certificate authority CA selects two multiplicative cyclic groups G1 and G2 with order p as prime number, generates element g∈G1, defines bilinear mapping e: G1×G1→G2, and takes three anti-collision hash functions H2: {0, 1} * →G1,H3:G2→{0,1} * , publish public parameters CP = {p, g, e, H1, H2, H3};

[0067] S12. Random selection of certificate authority CA As the private key sk of vaccine recipient i i , calculate its public key Random Selection As the private key sk of hospital h h , calculate its public key Random Selection As the private key sk of the national alliance chain node c c , calculate its public key Random Selection As the private key sk of the world alliance chain node w w , calculate its public key

[0068] S13. The certificate authority CA distributes the public and private key pairs obtained in step S12 to each member of the blockchain system including the vaccine recipient i, hospital h, national alliance chain node c and world alliance chain node w through a secure channel.

[0069] S2. After the vaccine recipient i is vaccinated in hospital h, hospital h generates an immunity passport m for the vaccine recipient i and assigns a passport number PUID i ;

[0070] In step S2, Figure 3 As shown, the immunity passport m includes the user's personal information and vaccination information. The vaccination information includes the vaccination time, vaccination location and vaccine information. The vaccine information includes the manufacturer, type, validity period, number of completed doses, etc.

[0071] S3, hospital h for immunity passport m and passport number PUID i Encryption is performed, and a hash value H1(C1) of the ciphertext C1 of the immunity passport m is generated, and the ciphertext C1 of the immunity passport m is uploaded to the hospital server for storage;

[0072] In step S3, hospital h checks the immunity passport m and the passport number PUID i Encryption is performed, specifically, hospital h randomly selects a secret value in, is the remainder class of integers modulo p, that is calculate k=e(g θ , H2(PUID i )), B = k × m, F = H3 (k), where pk i is the public key of vaccine recipient i, e is the bilinear mapping defined in step S11, g is the generator of G1, G1 is a multiplicative cyclic group whose order is a prime number p, H2 and H3 are two collision-resistant hash functions, m is the plaintext data of the immunity passport, and C1 = (A, B) is the ciphertext of the immunity passport m, and C2 = (A, F) is the immunity passport number PUID i The ciphertext.

[0073] S4, hospital h uses the ciphertext hash value H1(C1), keyword index I K Generate transaction T with the validity period T of the immunity passport C , and trade T C Upload to the national alliance chain node; specifically,

[0074] S41, hospital h uses searchable encryption technology to identify the PUID of the immune passport i The ciphertext C2 constructs the keyword index I K = <c2>;

[0075] S42, hospital h uses the hash value H1(C1) of the ciphertext of the immunity passport m, the validity period T of the immunity passport and the keyword index I K Generate transaction T C ; Transaction T C The structure of Figure 3 shown.

[0076] S43, Hospital h will trade T C The package is uploaded to the national alliance chain node, and the national alliance chain node runs the PBFT consensus mechanism to check the transaction T C Verify, and after successful verification, the national alliance chain node generates a new block C .

[0077] S5. National alliance chain nodes use searchable encryption technology to build a secure index I S , using the security index I S and validity period T to generate transaction T W And trade T W Upload to the World Alliance Chain; specifically,

[0078] S51. In each national alliance chain, the national alliance chain node extracts the keyword index I in each transaction in the block Blockc generated in step S43. K , validity period T and block identifier BID of the alliance chain of the country;

[0079] S52, using keyword index I K Construct security index I with national alliance chain block identifier BID S = <BID,I K >

[0080] S53, National Alliance Chain Node Utilization Security Index I S and validity period T to generate transaction T W ; Transaction T W The structure is as Figure 4 shown.

[0081] S54, the national alliance chain node will trade T W The package is uploaded to the World Alliance Chain. The World Alliance Chain nodes run the PBFT consensus mechanism to verify the transaction. After the verification is successful, the World Alliance Chain generates a new block. W .

[0082] S6. When the vaccine recipient i is asked to check the immunity passport m, for example, when the vaccine recipient i needs to go abroad and is asked to check the immunity passport m, the vaccine recipient i uses searchable encryption technology to check the passport number PUID i Generate Trapdoor T Q , and the trapdoor T Q Uploaded to the World Alliance Chain as a transaction; specifically,

[0083] S61. When the vaccine recipient i is asked to view the immunity passport m, the vaccine recipient i randomly selects a secret value in, Use your passport number PUID i ,calculate τ2=g d , where sk i is the private key of vaccine recipient i, pk w is the public key of the world alliance chain node w, H2 is the hash function defined in step S11, and g is the generator of G1;

[0084] S62, Generate Trapdoor T Q = <τ1, τ2>, where τ1 and τ2 are the parameters calculated in step S61, and the trapdoor T Q Uploaded to the World Alliance Chain as a transaction.

[0085] S7, World Alliance Link receives Trapdoor T Q After that, the smart contract is used to search for the ciphertext C1 of the corresponding immunity passport m. After finding it, the ciphertext C1 of the immunity passport m is sent to the vaccine recipient i; specifically,

[0086] S71, the world alliance chain node receives the trapdoor T Q = <τ1, τ2>, calculate Among them, sk w is the private key of the world alliance chain node w, and τ2 = g a is the parameter calculated in step S61;

[0087] S72, the block generated by the world alliance chain node in step S54 W Extract transaction T W Security Index I S = <BID,I K >, verify the equation Is it established? Where BID is the national alliance chain block identifier, I K = <c2>is the keyword index, C2=(A, F) is the immunity passport number PUID i The ciphertext, and F = H3(k) are the parameters calculated in step S3, k = e(g θ , H2(PUID i )),sk w is the private key of the world alliance chain node w, τ1 and τ2 are the parameters calculated in step S61, and e is the bilinear mapping defined in step S11; if it holds, then the transaction T is extracted W The national ID and national alliance chain block identifier BID;

[0088] S73. Find the corresponding national alliance chain according to the national ID;

[0089] S74. In the national alliance chain, access the corresponding block through the national alliance chain block identifier BID;

[0090] S75, extracting the hash value H1(C1) of the ciphertext C1 of the immunity passport m in the block and the hospital ID;

[0091] S76, using the hospital ID to find the corresponding hospital server, and after comparing the hash values, obtain the ciphertext C1=(A, B) of the immunity passport m;

[0092] S77, returning the ciphertext C1 of the immunity passport m to the alliance chain node;

[0093] S78. The alliance chain node sends the ciphertext C1 of the immunity passport m to the vaccine recipient.

[0094] S8. After receiving the immunization passport ciphertext C1, the vaccine recipient i decrypts it and obtains the immunization passport ciphertext data m for the staff to check; specifically,

[0095] S81. Vaccine recipient i receives the ciphertext C1=(A, B) of immunity passport m, where and B = k × m are the parameters calculated in step S3, k = e(g θ , H2(PUID i ));

[0096] S82. Calculate immune protection document data Among them, sk i is the private key of vaccinee i, and H2 is the hash function defined in step S11.

[0097] S9. Alliance chain nodes, including national alliance chain nodes and world alliance chain nodes, use smart contracts for regular maintenance to check whether the immunity passport m has expired, and update the expired immunity passport m. Specifically,

[0098] S91. The alliance chain node obtains the validity period T of the immunity passport m in the transaction;

[0099] S92, the alliance chain node obtains the timestamp t of the transaction;

[0100] S93. Alliance chain node obtains current time T cur ;

[0101] S94. Calculate T cur -t, if T cur -t≤T, it means that the current immunity passport m has not expired; if T cur -t>T, indicating that the current immunity passport m has expired. The relevant hospital is notified through the national alliance chain node to re-evaluate the immunity status of the vaccine recipient i and update the immunity passport for him.

[0102] The blockchain-based electronic immunity passport supervision method of the embodiment includes the following six entities:

[0103] Vaccine recipients: After receiving vaccination in the hospital, the vaccine recipients will generate their own immunity passports and obtain their own immunity passport numbers through the user terminal. When the vaccine recipients intend to go abroad, they will provide their immunity passport numbers to the inspectors for query, obtain the immunity passport ciphertext and decrypt it.

[0104] Hospital: After vaccinating the vaccine recipient, an immunity passport is generated and encrypted for the recipient through the terminal device, and the encrypted immunity passport data is uploaded to the hospital server for storage.

[0105] Hospital server: The hospital server stores the encrypted data of the vaccine recipient’s immunity passport.

[0106] National Alliance Chain: Each country maintains a corresponding national alliance chain, led by the National Health Commission. Domestic hospitals serve as nodes of the national alliance chain and adopt the PBFT consensus mechanism.

[0107] World Alliance Chain: Countries around the world jointly maintain a world alliance chain, led by the World Health Organization, with national health commissions and international health organizations serving as nodes of the world alliance chain, using the PBFT consensus mechanism.

[0108] Certificate Authority (CA): As a trusted third party, it initializes public parameters and generates and distributes keys to each member in the scheme.

[0109] This blockchain-based electronic immunity passport supervision method uses blockchain technology to save relevant data such as the index and the validity period of the immunity passport, ensuring the openness, traceability, and non-tamperability of the data, and realizing the openness and transparency of relevant data such as the index and the validity period of the immunity passport. It can effectively supervise the immunity passport data, provide reliable immunity passport data for the vaccine recipients, and facilitate the mutual recognition and interoperability of immunity passports in various countries, providing convenience for the vaccine recipients. It avoids the problem of immunity passport data being forged and the privacy leakage of personal information data. The search and regular maintenance of immunity passports are completed using blockchain smart contracts.

[0110] This blockchain-based electronic immunity passport supervision method uses searchable encryption technology to ensure the confidentiality of data and realize the sharing of immunity passport data. At the same time, it combines cryptography technology to solve the problems of privacy leakage and forgery of personal information data. Regarding the validity period of vaccines and immunity passports, this method uses smart contracts and timestamps and other technologies to supervise transactions on the alliance chain and detect the validity period of immunity passports in order to understand whether and when immunity passport holders need to re-evaluate their immunity status and update their passports.

[0111] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A blockchain-based electronic immunity passport supervision method, characterized by: The following steps are included: S1. The certificate authority CA initializes the public parameter CP according to the security parameters, generates and distributes the public and private key pairs for each member in the blockchain system, including the vaccine recipient i, the hospital h, the national alliance chain node c and the world alliance chain node w; S11. According to the input security parameter λ, the certificate authority CA selects two multiplicative cyclic groups G1 and G2 with order p as prime number, generates element g∈G1, defines bilinear mapping e: G1╳G2→G2, and takes three collision-resistant hash functions H1: {0,1}*→Z p *, H2: {0,1}*→G1, H3: G2→{0,1}*, publish public parameters CP={p, g, e, H1, H2, H3}, where p is a prime number, g is the generator of the multiplicative cyclic group G1, e is a bilinear map, and H1, H2 and H3 are three collision-resistant hash functions; S12, the certificate authority CA randomly selects x i ∈Z p * As the private key sk of the vaccine recipient i i , calculate its public key Randomly select x h ∈Z p * As the private key sk of hospital h h , calculate its public key Randomly select x c ∈Z p * As the private key sk of the national alliance chain node c c , calculate its public key Randomly select x w ∈Z p * As the private key sk of the world alliance chain node w w , calculate its public key S13, the certificate authority CA distributes the public and private key pairs obtained in step S12 to each member of the blockchain system including the vaccine recipient i, hospital h, national alliance chain node c and world alliance chain node w through a secure channel; S2. After the vaccine recipient i is vaccinated in hospital h, hospital h generates an immunity passport m for the vaccine recipient i and assigns a passport number PUIDi; wherein the immunity passport m includes the user's personal information and vaccination information, and the vaccination information includes the vaccination time, vaccination location and vaccine information; S3. Hospital h encrypts the immunity passport m and the passport number PUIDi, and generates a hash value H1(C1) of the ciphertext C1 of the immunity passport m, and uploads the ciphertext C1 of the immunity passport m to the hospital server for storage; In step S3, hospital h encrypts the immunity passport m and the passport number PUIDi. Specifically, hospital h randomly selects a secret value, θ∈Z p * Among them, Z p * is the remainder class of integers modulo p, that is, Z p * = {1, 2, ..., p-1}, calculate k=e(g θ , H2(PUID i )), B = k × m, F = H3 (k), where pk i is the public key of vaccine recipient i, e is the bilinear mapping defined in step S11, g is the generator of G1, G1 is a multiplicative cyclic group whose order is a prime number p, H2 and H3 are two collision-resistant hash functions, m is the plaintext data of the immunity passport, C1 = (A, B) is the ciphertext of the immunity passport m, and C2 = (A, F) is the ciphertext of the immunity passport number PUIDi; S4, hospital h uses the ciphertext hash value H1(C1), keyword index I K Generate transaction Tc with the validity period T of the immunity passport, and upload transaction Tc to the national alliance chain node; S5. National alliance chain nodes use searchable encryption technology to build a secure index I S , using the security index I S and validity period T to generate transaction T W And trade T W Upload to the World Alliance Chain; S6. When the vaccine recipient i is asked to check the immunity passport m, the vaccine recipient i uses searchable encryption technology to generate a trapdoor T according to the passport number PUIDi. Q , and the trapdoor T Q Uploaded to the World Alliance Chain as a transaction; S7, World Alliance Link receives Trapdoor T Q After that, the smart contract is used to search for the ciphertext C1 of the corresponding immunity passport m. After finding it, the ciphertext C1 of the immunity passport m is sent to the vaccine recipient i; S8. After receiving the immunization passport ciphertext C1, the vaccine recipient i decrypts it and obtains the immunization passport ciphertext data m for viewing; specifically, S81. Vaccine recipient i receives the ciphertext C1=(A, B) of immunity passport m, where and B = k × m are the parameters calculated in step S3, k = e(g θ , H2(PUID i )); S82. Calculate immune protection document data Among them, sk i is the private key of vaccinee i, H2 is the hash function defined in step S11; S9. Alliance chain nodes, including national alliance chain nodes and world alliance chain nodes, use smart contracts for regular maintenance to check whether the immunity passport m is expired and update the expired immunity passport m.

2. The blockchain-based electronic immunity passport supervision method according to claim 1, characterized in that: In step S4, hospital h uses the ciphertext hash value H1(C1) and the keyword index I K The validity period T of the immunity passport generates a transaction Tc, and uploads the transaction Tc to the national alliance chain node, specifically, S41, hospital h uses searchable encryption technology to construct a keyword index I based on the ciphertext C2 of the immunity passport number PUIDi K = <c2> ；< / c2> S42, hospital h uses the hash value H1(C1) of the ciphertext of the immunity passport m, the validity period T of the immunity passport and the keyword index I K Generate transaction T C ; S43, Hospital h will trade T C The package is uploaded to the national alliance chain node, and the national alliance chain node runs the PBFT consensus mechanism to check the transaction T C Verify, and after successful verification, the national alliance chain node generates a new block C .

3. The blockchain-based electronic immunity passport supervision method according to claim 1, characterized in that: In step S5, the national alliance chain node uses searchable encryption technology to build a security index I S , using the security index I S and validity period T to generate transaction T W And trade T W Upload to the World Alliance Chain, specifically, S51. In each national alliance chain, the national alliance chain node extracts the block generated in step S43. C The keyword index in each transaction I K , validity period T and block identifier BID of the alliance chain of the country; S52, using keyword index I K Construct security index I with national alliance chain block identifier BID S = <BID,I K > S53, National Alliance Chain Node Utilization Security Index I S and validity period T to generate transaction T W ; S54, the national alliance chain node will trade T W The package is uploaded to the World Alliance Chain. The World Alliance Chain nodes run the PBFT consensus mechanism to verify the transaction. After the verification is successful, the World Alliance Chain generates a new block. W .

4. The blockchain-based electronic immunity passport supervision method according to claim 1, characterized in that: In step S6, when the vaccine recipient i is asked to check the immunity passport m, the vaccine recipient i uses searchable encryption technology to generate a trapdoor T according to the passport number PUIDi. Q , and the trapdoor T Q Uploaded to the World Alliance Chain as a transaction, specifically, S61. When the vaccine recipient i is asked to view the immunity passport m, the vaccine recipient i randomly selects a secret value in, Use your passport number PUID i ,calculate τ2=g d , where sk i is the private key of vaccine recipient i, pk w is the public key of the world alliance chain node w, H2 is the hash function defined in step S11, and g is the generator of G1; S62, Generate Trapdoor T Q = <τ1, τ2>, where τ1 and τ2 are the parameters calculated in step S61, and the trapdoor T Q Uploaded to the World Alliance Chain as a transaction.

5. The blockchain-based electronic immunity passport supervision method as claimed in claim 3 is characterized in that: In step S7, the world alliance link receives the trap door T Q After that, the smart contract is used to search for the ciphertext C1 of the corresponding immunity passport m. After finding it, the ciphertext C1 of the immunity passport m is sent to the vaccine recipient i. Specifically, S71, the world alliance chain node receives the trapdoor T Q = <τ1, τ2>, calculate Among them, sk w is the private key of the world alliance chain node w, and τ2 = g d is the parameter calculated in step S61; S72, the block generated by the world alliance chain node in step S54 W Extract transaction T W Security Index I S = <BID,I K >, verify the equation Is it established? Where BID is the national alliance chain block identifier, I K = <c2>is the keyword index, C2=(A, F) is the immunity passport number PUID i The ciphertext, and F = H3(k) are the parameters calculated in step S3, k = e(g θ , H2(PUID i )),sk w is the private key of the world alliance chain node w, τ and τ2 are the parameters calculated in step S61, and e is the bilinear mapping defined in step S11; if it holds, then the transaction T is extracted W The national ID and national alliance chain block identifier BID; S73. Find the corresponding national alliance chain according to the national ID; S74. In the national alliance chain, access the corresponding block through the national alliance chain block identifier BID; S75, extracting the hash value H1(C1) of the ciphertext C1 of the immunity passport m in the block and the hospital ID; S76, using the hospital ID to find the corresponding hospital server, and after comparing the hash values, obtain the ciphertext C1=(A, B) of the immunity passport m; S77, returning the ciphertext C1 of the immunity passport m to the alliance chain node; S78. The alliance chain node sends the ciphertext C1 of the immunity passport m to the vaccine recipient.

6. The blockchain-based electronic immunity passport supervision method according to any one of claims 1 to 4, characterized in that: In step S9, the alliance chain nodes including the national alliance chain nodes and the world alliance chain nodes use smart contracts for regular maintenance to check whether the immunity passport m is expired, and update the expired immunity passport m, specifically, S91. The alliance chain node obtains the validity period T of the immunity passport m in the transaction; S92, the alliance chain node obtains the timestamp t of the transaction; S93. Alliance chain node obtains current time T cur ; S94. Calculate T cur -t, if T cur -t≤T, it means that the current immunity passport m has not expired; if T cur -t>T, indicating that the current immunity passport m has expired. The relevant hospital is notified through the national alliance chain node to re-evaluate the immunity status of the vaccine recipient i and update the immunity passport for him.

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