Decentralization identity verification method based on password accumulator

Abstract

The invention provides a decentralized cross-chain user identity authentication method based on a password accumulator. The method comprises the steps that a representative node registers a cross-chain system identity for a user; the plurality of representative nodes jointly run a threshold signature protocol to generate an access voucher for the user; the relay chain verifies signature information and member certification information in the user cross-chain request based on the on-chain identity of the user and an accumulator, and if verification is passed, cross-chain transaction is allowed; and the representative node verifies the signature information and the member proof information in the user identity revocation request, if the verification is passed, the representative node and other representative nodes operate a threshold signature protocol together, and the proxy chain management node issues revocation elements and updates the accumulator. By utilizing the scheme of the invention, the user identity can be quickly verified in a decentralized cross-chain transaction scene, and credible access and identity revocation of the user are supported.

Description

Technical Field

[0001] The present invention relates to the technical field of blockchain, and in particular to a decentralized identity authentication method based on a password accumulator. Background Art

[0002] Blockchain is a decentralized distributed ledger technology that combines distributed storage, peer-to-peer transmission, consensus mechanism and cryptography to record transactions and information through a growing data block chain to ensure data security and transparency.

[0003] In recent years, blockchain technology has been developing continuously, and blockchain applications are increasing. However, due to the differences in consensus mechanisms and block structures of different blockchains, the resources and data in the blockchain cannot be shared between chains, forming data islands. However, in actual applications, a blockchain may need to share data with other blockchains to complete complex business, but for non-public architectures such as alliance chains, there is a strict access mechanism, and data sharing cannot be completed with other blockchains. Cross-chain technology can exchange and circulate information and value on independent blockchains. However, each blockchain has an independent identity management mechanism, and there is a lack of a unified identity management mechanism between blockchains. It is difficult for entities in different blockchains to trust each other's identities, and entities in different blockchains cannot determine each other's identities. Therefore, the cross-chain system requires a unified identity management architecture to provide trusted identity management for the entire cross-chain system and realize identity mutual recognition between users of different blockchains.

[0004] At present, the identity authentication methods in the prior art rely on centralized institutions, and the personal information of users is in the hands of third-party institutions. Users cannot master their identities independently, and there are problems such as single point failure and privacy leakage. If the identity authentication technology in the prior art is applied to the cross-chain system, the degree of decentralization and credibility of the entire blockchain network will be reduced. In addition, the centralized authentication method in the prior art cannot meet the efficient authentication conditions required for frequent transactions of a large number of entities in the cross-chain scenario. The existing distributed cross-chain identity authentication methods lack a privacy protection mechanism, which may lead to the leakage of cross-chain user identity information. In addition, how to manage and verify the trust issues in the issuance and update process of cross-chain identity credentials has not been clarified. If a centralized institution is responsible, it may lead to single point failure and single point of evil. The performance and delay issues of the cross-chain system in the process of large-scale user use, especially in the case of high-frequency cross-chain operations, have not been mentioned by the existing solutions. In addition, the existing cross-chain identity authentication schemes do not take into account the timely revocation of cross-chain identity credentials, which may cause security problems for the cross-chain system.

[0005] A multi-chain unified identity management method based on DID (Decentralized IDentity, DID) and relay chain in the prior art includes: the method includes multiple alliance chain CAs (Certificate Authority) forming a relay chain for maintaining the global identity of users in the multi-chain system; the user inputs the user registration information to the relay chain, and generates the user's global DID identity on the relay chain; the alliance chain CA obtains the user's global DID identity in the relay chain, and issues an identity binding certificate for the user of the alliance chain identity and the user's global DID identity binding relationship; then the alliance chain CA issues the user an on-chain data certificate for the alliance chain identity and the on-chain data binding relationship; the user applies for cross-chain access rights from other alliance chain CAs based on the user's global DID identity, identity binding certificate and on-chain data certificate. This method can effectively provide a unified user identity for a multi-chain system facing an alliance chain, and provide a cross-chain access authorization and permission authentication mechanism for cross-chain access operations of alliance chain users.

[0006] (2) Cross-chain system and distributed user identity authentication method for cross-chain system

[0007] The method includes a user identification registration module, a user identification update module and a user identification authentication module. The user identification registration module is used to issue a cross-chain system unified identity C-BUID to users on the blockchain connected to the cross-chain system. The user identification update module is used to update the identity information of users registered in the cross-chain system on each independent blockchain, so as to realize identity interconnection in the cross-chain system. Here, independent blockchains refer to different blockchain systems. During cross-chain interaction, the independent blockchain sends the user's information to the cross-chain system, and the system queries the cross-chain identity according to the information uploaded by the user, updates the relevant attribute information, and records the attribute mapping relationship. The user identification authentication module is used for user identity authentication on each independent blockchain in the cross-chain system, and the cross-chain identity authentication is designed based on digital signatures and interactive zero-knowledge proofs.

[0008] The disadvantages of the multi-chain unified identity management method based on DID and relay chain in the above-mentioned prior art include: (1) In the cross-chain entity identity management architecture, the validity period of the identity certificate is very important. This method does not mention the validity period management and certificate revocation mechanism of the cross-chain entity identity certificate. In addition, the above scheme does not mention the synchronization problem of identity update. When the user's identity information changes on a certain blockchain, it is not clear how to synchronize it to other blockchains in real time.

[0009] (2) As the number of cross-chain entities increases, the pressure on on-chain storage and network communication of the blockchain increases. The above scheme transfers all identity management functions of cross-chain users to the relay chain and relies on interactive zero-knowledge proof, which brings additional communication and computing overhead to the relay chain and reduces the robustness of the system in complex network environments. Summary of the invention

[0010] The present invention provides a decentralized identity authentication method based on a password accumulator to effectively ensure the security and credibility of a cross-chain system.

[0011] In order to achieve the above object, the present invention adopts the following technical scheme.

[0012] A decentralized identity authentication method based on a password accumulator, comprising:

[0013] The cross-chain system is initialized, and the cross-chain user sends a registration request to the representative node of the blockchain where the user is located. The registration request carries the identity information of the user. The representative node forwards the registration request to the proxy chain, and the proxy chain stores the identity information of the cross-chain user.

[0014] The cross-chain user sends an application access certificate to the representative node, and the representative node forwards the application access certificate to other representative nodes of the user proxy chain. The representative node generates an access certificate based on the signature returned by other representative nodes, and sends the certificate hash value to the proxy chain. After the proxy chain verifies the identity information of the cross-chain user, it adds the password accumulator to the certificate hash value to generate a member proof value, and sends the member proof value to the cross-chain user;

[0015] The proxy chain and the relay chain synchronize the cryptographic accumulator, the cross-chain user sends a cross-chain transaction request to the relay chain, and the cross-chain transaction request carries the member proof value and other cross-chain transaction information. After the relay chain successfully authenticates the member proof value in the cross-chain transaction request using the cryptographic accumulator, it returns an authentication success message to the cross-chain user.

[0016] Preferably, the cross-chain system is initialized, including:

[0017] During the initialization phase of the cross-chain system, each application chain elects a representative node as the authoritative node of the chain. All representative nodes together constitute a proxy chain. Each representative node registers its cross-chain identity with the proxy chain as a global trusted identity. The cross-chain system administrator sets security parameters, selects elliptic curves and bilinear pairings, generates a public-private key pair {PK, SK}, and divides the private key SK into n parts using the Shamir secret sharing algorithm. Each representative node CA i Get the public key share Pk i and private key share Ski , i represents the representative node of the i-th blockchain. There are n representative nodes participating in the cross-chain system. The threshold parameter of the threshold signature used for successfully issuing the access certificate is t. The proxy chain generates the initial value g of the cryptographic accumulator. For the set X = {x1, x2, …, x n The password accumulator of} is defined as Acc X =Sum(g,{x1,x2,…,x n}), where Sum and Revoke are the aggregation and revocation operations of the password accumulator, Acc old Represents the current password accumulator, Acc new Represents an updated cryptographic accumulator.

[0018] Preferably, the cross-chain user sends a registration request to the representative node of the blockchain where the user is located, and the registration request carries the identity information of the cross-chain user. The representative node forwards the registration request to the proxy chain, and the proxy chain stores the identity information of the cross-chain user, including:

[0019] S11: Cross-chain users independently generate cross-chain unified identity identifier DID and public-private key pair {Pk U ,Sk U}, using the private key Sk U For DID and public key Pk U , related attribute information Attr, timestamp T1 information signature, get Sig1 U , send a cross-chain identity registration request M1 = {Register, DID, Pk U ,Attr,T1,Sig1 U};

[0020] S12: Representative node CA i After verifying the cross-chain identity registration request, submit the cross-chain identity registration request to the proxy chain for registration, and the proxy chain stores the cross-chain unified identity identifier DID and DID document of the cross-chain user;

[0021] S13: After successful registration, the representative node returns registration success information to the cross-chain user. The cross-chain user has a legal identity in the cross-chain system, and other users can query the identity information of the cross-chain user on the proxy chain.

[0022] Preferably, the cross-chain user sends an application access certificate to the representative node, the representative node forwards the application access certificate to other representative nodes of the proxy chain, the representative node generates an access certificate according to the signature returned by other representative nodes, and sends the certificate hash value to the proxy chain. After the proxy chain verifies the identity information of the cross-chain user, it adds the password accumulator to the certificate hash value to generate a member proof value, and sends the member proof value to the cross-chain user, including:

[0023] S21: The cross-chain user uses the private key Sk U For DID and public key Pk U , the hash value signature of the relevant attribute information Attr and the timestamp T2 information, and obtains Sig2 U , the cross-chain user sends a i Apply for access credentials and send message M2 = {ApplyAccess, DID, Pk U ,Attr,T2,Sig2 U};

[0024] S22: Representative node CA i Verify the message M2, and after verification, forward the message M2 to other representative points CAs;

[0025] S23: Other representative nodes CAs read the DID document of the cross-chain user in the proxy chain for verification. After verification, use their own private key share Sk CAs Calculate partial signature And send it to the representative node CA i Send i and other relevant information required for the combined signature;

[0026] S24: Representative node CA i Collect at least t valid threshold signatures σ1,σ2,…,σ t , verify the collected signatures e(σ i ,g)=e(Hash(M2),Pk i ), if the equation holds, then it means that σ i If it is generated by a legitimate signer, keep the legitimate signature; otherwise, discard the signature and merge the legitimate signatures to generate a complete threshold signature. Where S represents the set of signing participants, λ i is the Lager-Ranger coefficient, λ i =∏ j∈S,j≠i j / (ji);

[0027] S25: Representative node CA iVerify that the signature is valid by calculating e(σ,g)=e(Hash(M2),PK);

[0028] S26: After verification, the representative node CA i Generate access certificate VC = {DID, Pk U ,Attr,σ}, represents the node CA i Hash the admission certificate VC to calculate Hash(VC), and upload Hash(VC) to the proxy chain;

[0029] S27: Representative node CA i Calculate the hash value x i = Hash(VC), using the dynamic password accumulator algorithm to convert the hash value x i Add to the password accumulator to generate a new password accumulator value Acc new =Sum(Acc old ,x i ), and let x i Membership certificate is

[0030] S28: Representative node CA i Set the new password accumulator value Acc new and the hash value x of the new user certificate i Publish to the proxy chain;

[0031] S29: The proxy chain sends a new element x to the relay chain i The credential set X = {x1, x2, ... x i ,…,x n}'s password accumulator Acc new ;

[0032] S30: Representative node CA i Return a message of successful admission to the cross-chain user, representing the node CA i Add the current timestamp T3 and use the private key pair The hash value is signed to get Sig CA , send a message M3 = {AcceptAccess, pf i ,VC,T3,Sig CA}.

[0033] Preferably, the proxy chain and the relay chain synchronize the cryptographic accumulator, the cross-chain user sends a cross-chain transaction request to the relay chain, the cross-chain transaction request carries the member proof value and cross-chain transaction information, and after the relay chain successfully authenticates the member proof value in the cross-chain transaction request using the cryptographic accumulator, it returns an authentication success message to the cross-chain user, including:

[0034] S31: The cross-chain user uses a private key pair The hash value Hash(M) is signed to get Sig3 U , the cross-chain user sends a cross-chain transaction message to the relay chain otherinfos is other relevant information required for this cross-chain transaction;

[0035] S32: After the relay chain receives the cross-chain transaction message M4, it uses the public key Pk provided by the cross-chain user U Verify the signature Sig3 with the cross-chain transaction information M4 U , if true, then the signature is made by Pk U The corresponding private key is generated, and step S33 is executed; otherwise, the verification fails and the cross-chain transaction message M4 is rejected;

[0036] S33: Relay Chain Verification x i = Hash (VC) is established, and through the judgment equation Is verification x established? i Is it Acc X If true, it means that the cross-chain user is the owner of the DID identity and has a legal cross-chain access certificate, allowing cross-chain transactions; otherwise, the cross-chain transaction is rejected.

[0037] Preferably, the method further comprises:

[0038] S41: Cross-chain users to proxy node CA i Send a withdrawal request Sig4 U For cross-chain users signature;

[0039] S42: Representative node CA i Verify the revocation request M5 based on the user public key and the password accumulator value. If the verification is successful, forward the revocation request M5 to other representative points CAs and proceed to the next step S43. Otherwise, reject the revocation request M5.

[0040] S43: After receiving the revocation request M5, other representative nodes authenticate the cross-chain user. After the identity verification is passed, if they agree to revoke the user's credentials, they will use their own private key share Sk CAs Calculate partial signature And send it to the representative node CA i Send revokei and other relevant information required for the combined signature;

[0041] S44: Representative node CA i Count the number of valid signatures. If the number of passed signatures reaches the preset threshold t, the verification is successful, and the representative node generates a complete threshold signature σ revoke , and generate the final revocation certificate Representative Node CA i Send the revocation certificate to the proxy chain management node;

[0042] S45: The proxy chain management node verifies the threshold signature σ revoke After the validity is verified, the password accumulator revocation algorithm is called to revoke the access credentials of the cross-chain user. The administrator uses the dynamic password accumulator revocation algorithm Acc new =Revoke(Acc old ,x i ) Update the value of the password accumulator, publish the new password accumulator value to the proxy chain and synchronize the updated password accumulator Acc to the relay chain new ;

[0043] S46: The management node publishes the revoked element xi to the proxy chain, and the remaining users x on the proxy chain j calculate It is the new witness value. Other users use the new witness value to authenticate cross-chain transactions.

[0044] S47: The management node sends the cross-chain user’s identity DID and revocation certificate VC revoke Publish to the proxy chain.

[0045] It can be seen from the technical solution provided by the above-mentioned embodiments of the present invention that the present invention records the access credentials of cross-chain users through a dynamic password accumulator, and combines it with a digital signature, introduces a proxy blockchain to design a decentralized and efficient cross-chain identity authentication scheme based on a password accumulator, thereby realizing efficient verification and revocation of user identities, reducing the storage pressure of the relay chain, and preventing replay attacks and identity forgery, thereby ensuring the security and credibility of the entire cross-chain system.

[0046] Additional aspects and advantages of the present invention will be given in part in the following description, which will become obvious from the following description, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0048] Figure 1 A model structure diagram of a cross-chain identity management system provided in an embodiment of the present invention.

[0049] Figure 2 A timing diagram of a cross-chain identity management system provided by an embodiment of the present invention.

[0050] Figure 3 A flowchart of a cross-chain identity management phase provided by an embodiment of the present invention.

[0051] Figure 4 A flow chart of entity interaction of steps S2 to S3 provided in an embodiment of the present invention;

[0052] Figure 5 A flow chart of entity interaction of step S4 is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0054] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items.

[0055] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0056] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each embodiment does not constitute a limitation on the embodiments of the present invention.

[0057] The model structure of a cross-chain identity management system provided by an embodiment of the present invention is as follows: Figure 1 As shown in Figure 1, the cross-chain identity management system includes cross-chain user identity registration, cross-chain access certificate issuance, cross-chain user identity authentication, and cross-chain user identity revocation. The model structure includes four roles: cross-chain user, relay chain, proxy chain, and representative node. The following are the definitions of the four roles.

[0058] Cross-chain users: Cross-chain users have a legal identity on a blockchain and want to conduct cross-chain transactions with other blockchains. They need to register a cross-chain unified identity with the proxy chain and apply for access credentials from the representative node to obtain access credentials and membership proof values. Users submit identity proof and membership proof to the relay chain, and after verification, they can use the cross-chain function provided by the relay chain to complete cross-chain transactions.

[0059] Relay chain: The relay chain maintains a password accumulator, deploys an identity verification contract, verifies the identity proof and membership proof submitted by the user, and after the verification is passed, subsequent operations can be performed. In the present invention, the relay chain maintains a password accumulator, which can quickly verify the identity of cross-chain users and reduce the storage pressure of the relay chain.

[0060] Representative node: Each blockchain elects a representative node as the trust node of the blockchain, and forms a proxy alliance with other representative nodes to issue access certificates based on threshold signatures. Representative nodes can periodically verify each other, making the proxy alliance highly credible.

[0061] Proxy chain: Each blockchain elects a representative node as the representative of the chain to jointly maintain the proxy chain with other representative nodes. As the distributed trust agency of the entire cross-chain system, it is responsible for the distributed digital identity management of the entire cross-chain system, including the storage and maintenance of cross-chain user identities, etc. It also deploys the identity registration contract to complete the user's identity registration, the password accumulator contract to complete the relevant operations on the password accumulator, and synchronizes the latest password accumulator to the relay chain.

[0062] A decentralized identity authentication method based on a cryptographic accumulator provided by an embodiment of the present invention includes a system initialization phase and a cross-chain identity management phase. The cross-chain identity management phase mainly includes cross-chain entity identity registration, access credential issuance, identity authentication, and identity revocation. In the system initialization phase, each application chain elects a representative node as the authoritative node of the chain to jointly form a proxy chain, and registers its own cross-chain identity with the proxy chain as a globally trusted identity. The cross-chain system administrator sets security parameters, selects elliptic curves and bilinear pairings, generates a public-private key pair {PK, SK}, and divides the private key SK into n parts using the Shamir secret sharing algorithm. Each representative node CA i Get the public key share Pk i and private key share Sk i , where i represents the representative node of the i-th blockchain, and there are n representative nodes participating in the cross-chain system. The threshold parameter of the threshold signature used for successfully issuing the access certificate is t. The proxy chain generates the initial value g of the cryptographic accumulator, and stipulates that for the set X = {x1, x2, …, x n The password accumulator of} is defined as Acc X =Sum(g,{x1,x2,…,x n}), where Sum and Revoke are the aggregation and revocation operations of the password accumulator. X In the following, Acc new or Acc old Replacement, Acc old Represents the current password accumulator, Acc new Represents the updated password accumulator. The system uses a unified hash algorithm Hash and assumes that there is a secure communication channel between the user and the representative node of the chain.

[0063] A timing diagram of a cross-chain identity management system provided by an embodiment of the present invention is as follows: Figure 2 As shown, a flowchart of a cross-chain identity management phase provided by an embodiment of the present invention is as follows Figure 3 As shown, the specific steps include:

[0064] Step S1: Cross-chain user unified identity registration, specifically including the following steps:

[0065] S11: Users independently generate cross-chain unified identity DID and public-private key pair {Pk U ,SK U}, using the private key SK U For DID and public key Pk U , relevant attribute information Attr, timestamp T1 and other information signatures to obtain Sig1 U , send a cross-chain identity registration request M1 = {Register, DID, PkU ,Attr,T1,Sig1 U}.

[0066] S12: Representative node CA i Verify the registration request and submit it to the proxy chain for registration to obtain the user's cross-chain unified identity DID and DID document.

[0067] S13: After successful registration, the representative node returns the registration success information to the user. The user has the legal identity of the cross-chain system and can perform subsequent cross-chain operations based on the DID. Other users can query the user's identity information on the proxy chain.

[0068] Step S2: issuing access credentials, Figure 4 A flow chart of entity interaction from step S2 to step S3 provided in an embodiment of the present invention.

[0069] S21: The user applies to the proxy chain to access the relay chain. Accessing the relay chain means that the user can use the relay chain for cross-chain operations. The user uses the private key Sk U For DID and public key Pk U , the hash value signature of the relevant attribute information Attr, timestamp T2 and other information, and obtain Sig2 U . The user sends a request to the CA representative node i Apply for access credentials and send message M2 = {ApplyAccess, DID, Pk U ,Attr,T2,Sig2 U}.

[0070] S22: Representative node CA i The message is verified and, after passing the verification, it is forwarded to other representative points CAs.

[0071] S23: Other representative nodes CAs can read the DID document of the user in the proxy chain for verification. After verification, use their own private key share Sk CAs Calculate partial signature And send it to the representative node CA i Send i and other relevant information required for the merge signature.

[0072] S24: Representative node CA i Collect at least t valid threshold signatures σ1,σ2,…,σ t , verify the collected signatures e(σ i ,g)=e(Hash(M2),Pk i ), if the equation holds, then σ iThe signature is generated by a legitimate signer, otherwise it is discarded. The signatures are merged to generate a complete threshold signature. Where S represents the set of signing participants, λ i is the Lager-Ranger coefficient, λ i =∏ j∈S,j≠i j / (ji).

[0073] S25: Representative node CA i The validity of the signature can be verified by calculating e(σ,g)=e(Hash(M2),PK).

[0074] S26: After verification, the representative node CA i Generate access credentials VC for the user = {DID, Pk U ,Attr,σ}. Represents the node CA i The certificate is hashed to Hash(VC) and uploaded to the proxy chain. Other representative nodes in the proxy chain can verify VC to prevent the representative node CA from i Do evil.

[0075] S27: Representative node CA i Calculate the hash value x i = Hash(VC), and use the dynamic password accumulator algorithm to add it to the password accumulator to generate a new password accumulator value Sum(Acc old ,x i ), and let x i Membership certificate is

[0076] S28: Representative node CA i Set the new password accumulator value Acc new and the hash value x of the new user certificate i Published to the proxy chain for other users to update the witness value. Other users can calculate the new witness value p

[0077] S29: The proxy chain sends a new element x to the relay chain i The credential set X = {x1, x2, ... x i ,…,x n}'s password accumulator Acc new .

[0078] S30: Representative node CA i Returns a successful admission message to the user. Representative node CA i Add the current timestamp T3 and use the private key pair The hash value is signed to get SigCA , send a message M3 = {AcceptAccess, pf i ,VC,T3,Sig CA}.

[0079] Step S3: Authentication of user's cross-chain identity, including the following steps:

[0080] S31: The user sends a cross-chain transaction to the relay chain. The user uses the private key pair The hash value Hash(M) is signed to get Sig3 U , send cross-chain transaction M4 = { otherinfos is other relevant information required for this cross-chain transaction.

[0081] S32: After receiving the cross-chain message, the relay chain verifies the request based on the user's public key and the password accumulator value. First, check the timestamp to prevent replay attacks and use the public key Pk provided by the user. U Verify the signature Sig3 with the cross-chain transaction information M4 U If true, it means that the signature is made by Pk U The corresponding private key is generated, and the next step S33 can be carried out to verify that the user is the owner of the DID and whether the user has a legal access certificate; otherwise, the verification fails and the message is rejected.

[0082] S33: Relay Chain Verification x i = Hash (VC) is established, and through the judgment equation Is verification x established? i Is it Acc X If true, it means that the user is the owner of the DID identity and has a legal cross-chain access certificate, allowing cross-chain transactions; otherwise, the cross-chain transaction is rejected.

[0083] Step S4: Revoke the access certificate. Figure 5 The entity interaction flow chart of step S4 provided in the embodiment of the present invention specifically includes the following steps:

[0084] S41: The user sends a revocation request to the proxy node CA i Send M5 = {ApplyRevoke, VC, T5, Sig4 U}. Among them, Sig4 U For users Signature.

[0085] S42: Representative Node CA iThe identity authentication method mentioned in S32 to S33 in step S3 is used to verify the request based on the user's public key and the password accumulator value to ensure the legitimacy of the user's identity. After the verification is passed, the message is forwarded to other representative points CAs and the next step S43 is performed, otherwise the request is rejected.

[0086] S43: After receiving the revocation request, other representative nodes will also authenticate the user. After the verification is passed, if the user's credentials are revoked, they will use their own private key share SK CAs Calculate partial signature And send it to the representative node CA i Send revokei and other relevant information required for the merge signature.

[0087] S44: Representative node CA i Count the number of valid signatures. If the number of signatures that pass reaches the preset threshold t, the verification is successful. The representative node generates a complete threshold signature σ revoke , and generate the final revocation certificate Representative Node CA i Send the revocation certificate to the proxy chain management node.

[0088] S45: The proxy chain management node verifies the validity of the signature. After the verification is passed, the password accumulator revocation algorithm is called to revoke the user's access credentials. The administrator uses the dynamic password accumulator revocation algorithm Acc new =Revoke(Acc old ,x i ) Update the value of the password accumulator, publish the new password accumulator value to the proxy chain and synchronize the updated password accumulator Acc to the relay chain new . Users whose credentials are revoked will not be able to pass the verification of the relay chain.

[0089] S46: The management node will revoke the element x i Published to the proxy chain, other users on the chain x j calculate The new witness value can be used by other users for cross-chain transaction identity authentication.

[0090] S47: The management node sends the user's identity DID and revocation certificate VC revoke Publish to the proxy chain. The query contract is deployed in the proxy chain, and other users can query the revocation record of the user's access certificate by providing the parameter DID to the contract.

[0091] In summary, in the embodiment of the present invention, the representative nodes elected by each application chain use threshold signatures to issue and revoke access credentials for cross-chain users, ensuring the decentralization of the access credential issuance and revocation process, and the hash value of the user's identity credential is stored in the proxy chain, which can be verified by other cross-chain entities. The registration, update, and revocation of user identities are all recorded on the proxy chain, which improves the security and credibility of the entire system.

[0092] The embodiment of the present invention optimizes the identity credential storage scheme, introduces a password accumulator, reduces the storage pressure of the relay chain, and combines the password accumulator with the digital signature technology to achieve efficient member verification, effectively preventing replay attacks and identity forgery, and ensuring that in the scenario of frequent cross-chain transactions by massive users in the cross-chain, the user's identity verification is completed quickly, thereby improving the performance of the entire cross-chain system. At the same time, the use of the password accumulator makes the identity credential more lightweight. In comparison, the present invention has more advantages in efficiency and security.

[0093] The embodiment of the present invention realizes the revocation of cross-chain entity identity based on dynamic password accumulator technology, and timely processes and updates the identities of expired users and malicious users. The revoked users will not be able to pass the identity authentication of the relay chain and cannot use the cross-chain system for cross-chain transactions, which improves the security and credibility of the system and helps to build a dynamic and secure cross-chain system.

[0094] The embodiment of the present invention optimizes the storage scheme of identity credentials, records the access credentials of cross-chain users through a dynamic password accumulator, and combines it with a digital signature to achieve efficient verification and revocation of user identities, reduce the storage and computing pressure of the relay chain, prevent replay attacks and identity forgery, and ensure the security and credibility of the entire cross-chain system.

[0095] The embodiment of the present invention introduces a proxy blockchain chain, and implements identity management functions such as issuance and revocation of cross-chain identity credentials based on threshold signature technology, thereby preventing single point evil or single point failure, and improving the decentralization and credibility of the entire system.

[0096] The embodiment of the present invention realizes the revocation of cross-chain user access credentials based on a dynamic password accumulator, revokes the identity of malicious entities in a timely manner, limits the malicious behavior of users, and enhances the security and credibility of the entire cross-chain system.

[0097] Those skilled in the art can understand that the accompanying drawings are only schematic diagrams of an embodiment, and the modules or processes in the accompanying drawings are not necessarily required to implement the present invention.

[0098] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present invention or certain parts of the embodiments.

[0099] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The device and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0100] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A decentralized identity authentication method based on a password accumulator, characterized in that: include: The cross-chain system is initialized, and the cross-chain user sends a registration request to the representative node of the blockchain where the user is located. The registration request carries the identity information of the user. The representative node forwards the registration request to the proxy chain, and the proxy chain stores the identity information of the cross-chain user. The cross-chain user sends an application access certificate to the representative node, and the representative node forwards the application access certificate to other representative nodes of the user proxy chain. The representative node generates an access certificate based on the signature returned by other representative nodes, and sends the certificate hash value to the proxy chain. After the proxy chain verifies the identity information of the cross-chain user, it adds the password accumulator to the certificate hash value to generate a member proof value, and sends the member proof value to the cross-chain user; The proxy chain and the relay chain synchronize the cryptographic accumulator, the cross-chain user sends a cross-chain transaction request to the relay chain, and the cross-chain transaction request carries the member proof value and other cross-chain transaction information. After the relay chain successfully authenticates the member proof value in the cross-chain transaction request using the cryptographic accumulator, it returns an authentication success message to the cross-chain user.

2. The method according to claim 1, characterized in that The cross-chain system is initialized, including: During the initialization phase of the cross-chain system, each application chain elects a representative node as the authoritative node of the chain. All representative nodes together constitute a proxy chain. Each representative node registers its cross-chain identity with the proxy chain as a global trusted identity. The cross-chain system administrator sets security parameters, selects elliptic curves and bilinear pairings, generates a public-private key pair {PK, SK}, and divides the private key SK into n parts using the Shamir secret sharing algorithm. Each representative node CA i Get the public key share Pk i and private key share Sk i , i represents the representative node of the i-th blockchain, and there are n representative nodes participating in the cross-chain system. The threshold parameter of the threshold signature used for successfully issuing the access certificate is t. The proxy chain generates the initial value g of the cryptographic accumulator. For the set X = {x1, x2, …, x n The password accumulator of} is defined as Acc X =Sum(g,{x1,x2,...,x n }), where Sum and Revoke are the aggregation and revocation operations of the password accumulator, Acc old Represents the current password accumulator, Acc new Represents an updated cryptographic accumulator.

3. The method according to claim 1, characterized in that The cross-chain user sends a registration request to the representative node of the blockchain where the user is located. The registration request carries the identity information of the cross-chain user. The representative node forwards the registration request to the proxy chain, and the proxy chain stores the identity information of the cross-chain user, including: S11: Cross-chain users independently generate cross-chain unified identity identifier DID and public-private key pair {Pk U , Sk U }, using the private key Sk U For DID and public key Pk U , related attribute information Attr, timestamp T1 information signature, get Sig1 U , send a cross-chain identity registration request M1 = {Register, DID, Pk U ,Attr,T1,Sig1 U }; S12: Representative node CA i After verifying the cross-chain identity registration request, submit the cross-chain identity registration request to the proxy chain for registration, and the proxy chain stores the cross-chain unified identity identifier DID and DID document of the cross-chain user; S13: After successful registration, the representative node returns registration success information to the cross-chain user. The cross-chain user has a legal identity in the cross-chain system, and other users can query the identity information of the cross-chain user on the proxy chain.

4. The method according to claim 3, characterized in that The cross-chain user sends an application access certificate to the representative node, the representative node forwards the application access certificate to other representative nodes of the proxy chain, the representative node generates an access certificate based on the signature returned by other representative nodes, and sends the certificate hash value to the proxy chain. After the proxy chain verifies the identity information of the cross-chain user, it adds the password accumulator to the certificate hash value to generate a member proof value, and sends the member proof value to the cross-chain user, including: S21: The cross-chain user uses the private key Sk U For DID and public key Pk U , the hash value signature of the relevant attribute information Attr and the timestamp T2 information, and obtains Sig2 U , the cross-chain user sends a i Apply for access credentials and send message M2 = {ApplyAccess, DID, Pk U ,Attr,T2,Sig2 U }; S22: Representative node CA i Verify the message M2, and after verification, forward the message M2 to other representative points CAs; S23: Other representative nodes CAs read the DID document of the cross-chain user in the proxy chain for verification. After verification, use their own private key share Sk CAs Calculate partial signature And send it to the representative node CA i Send i and other relevant information required for the combined signature; S24: Representative node CA i Collect at least t valid threshold signatures σ1,σ2,…,σ t , verify the collected signatures e(σ i , g) = e(Hash(M2), Pk i ), if the equation holds, then it means that σ i If it is generated by a legitimate signer, keep the legitimate signature; otherwise, discard the signature and merge the legitimate signatures to generate a complete threshold signature. Where S represents the set of signing participants, λ i is the Lager-Ranger coefficient, λ i =Π j∈S，j≠i j / (j_i); S25: Representative node CA i Verify that the signature is valid by calculating e(σ, g) = e(Hash(M2), PK); S26: After verification, the representative node CA i Generate access credentials VC = {DID, Pk U ,Attr,σ}, represents the node CA i Hash the admission certificate VC to calculate Hash(VC), and upload Hash(VC) to the proxy chain; S27: Representative node CA i Calculate the hash value x i = Hash(VC), using the dynamic password accumulator algorithm to convert the hash value x i Add to the password accumulator to generate a new password accumulator value Acc new =Sum(Acc old , x i ), and let x i Membership certificate is S28: Representative node CA i Set the new password accumulator value Acc new and the hash value x of the new user certificate i Publish to the proxy chain; S29: The proxy chain sends a new element x to the relay chain i The credential set X = {x1, x2, ... x i , …, x n }'s password accumulator Acc new ; S30: Representative node CA i Return a message of successful admission to the cross-chain user, representing the node CA i Add the current timestamp T3 and use the private key pair The hash value is signed to get Sig CA , send a message M3 = {AcceptAccess, pfi, VC, T3, Sig CA }.

5. The method according to claim 4, characterized in that The proxy chain and the relay chain synchronize the password accumulator, the cross-chain user sends a cross-chain transaction request to the relay chain, and the cross-chain transaction request carries the member proof value and cross-chain transaction information. After the relay chain successfully authenticates the member proof value in the cross-chain transaction request using the password accumulator, it returns an identity authentication success message to the cross-chain user, including: S31: The cross-chain user uses a private key pair The hash value Hash(M) is signed to get Sig3 U , the cross-chain user sends a cross-chain transaction message to the relay chain otherinfos is other relevant information required for this cross-chain transaction; S32: After the relay chain receives the cross-chain transaction message M4, it uses the public key Pk provided by the cross-chain user U Verify the signature Sig3 with the cross-chain transaction information M4 U , if true, then the signature is made by Pk U The corresponding private key is generated, and step S33 is executed; otherwise, the verification fails and the cross-chain transaction message M4 is rejected; S33: Relay Chain Verification x i = Hash (VC) is established, and through the judgment equation Is verification x established? i Is it Acc X If true, it means that the cross-chain user is the owner of the DID identity and has a legal cross-chain access certificate, allowing cross-chain transactions; otherwise, the cross-chain transaction is rejected.

6. The method according to claim 5, characterized in that The method further comprises: S41: Cross-chain users to proxy node CA i Send a withdrawal request Sig4 U For cross-chain users signature; S42: Representative node CA i Verify the revocation request M5 based on the user public key and the password accumulator value. If the verification is successful, forward the revocation request M5 to other representative points CAs and proceed to the next step S43. Otherwise, reject the revocation request M5. S43: After receiving the revocation request M5, other representative nodes authenticate the cross-chain user. After the identity verification is passed, if they agree to revoke the user's credentials, they will use their own private key share Sk CAs Calculate partial signature And send it to the representative node CA i Send revokei and other relevant information required for the combined signature; S44: Representative node CA i Count the number of valid signatures. If the number of passed signatures reaches the preset threshold t, the verification is successful, and the representative node generates a complete threshold signature σ revoke , and generate the final revocation certificate Representative Node CA i Send the revocation certificate to the proxy chain management node; S45: The proxy chain management node verifies the threshold signature σ revoke After the validity is verified, the password accumulator revocation algorithm is called to revoke the access credentials of the cross-chain user. The administrator uses the dynamic password accumulator revocation algorithm Acc new =Revoke(Acc old , x i ) Update the value of the password accumulator, publish the new password accumulator value to the proxy chain and synchronize the updated password accumulator Acc to the relay chain new ; S46: The management node will revoke the element x i Published to the proxy chain, other users on the proxy chain x j calculate It is the new witness value. Other users use the new witness value to authenticate cross-chain transactions. S47: The management node sends the cross-chain user’s identity DID and revocation certificate VC revoke Publish to the proxy chain.

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