Abstract: This disclosure relates to blockchain smart contract-based data processing. In one aspect, a method includes obtaining, by a node in a blockchain network in which a service smart contract is deployed, a service initiation transaction. The service initiation transaction is broadcast to other nodes. While executing the service initiation transaction, the service smart contract is invoked using a blockchain virtual machine that includes a first instruction set comprising a data exchange instruction and processing logic corresponding to the data exchange instruction. The node triggers execution of the processing logic based on the data exchange instruction in the service smart contract using the blockchain virtual machine, thereby performing a data exchange processing operation on data to be processed. A second instruction set of a smart contract compiler includes the data exchange instruction. The service smart contract is compiled using the smart contract compiler and includes the data exchange instruction.

Abstract: One embodiment provides a method and system for identity verification. During operation, a digital identity client executing on a computer receives an identity-verification request comprising an identifier of a user, sends a query for available identity-verification services to identity-verification-service-publishing blockchain, determines an identity-verification server based on a result of the query, interacts with the determined identity-verification server to complete identity verification of the user, generates a public-private key pair comprising a public key and a private key corresponding to the identifier of the user, and stores, in identity-verification blockchain, identity-verification information associated with the user. The identity-verification information comprises at least a hash value of the public key, thereby facilitating subsequent identity verification of the user based on the identity-verification information stored in the identity-verification blockchain.

Abstract: A method, a system, and a computer-readable storage medium for blockchain-based data processing are provided. The method comprises: by a node device of a service acceptance platform, receiving service processing application data of a target user; generating a first shared service processing result and a first private service processing result with respect to a target service data processing entity; sending a first transaction to a blockchain for the first transaction to be recorded in a distributed database of the blockchain upon verification of the first transaction by a plurality of node devices associated with the blockchain according to a consensus mechanism; and sending the first private service processing result to the node device of the target service data processing entity, for the node device of the target service data processing entity to generate a second service processing result.

Abstract: Implementations of the present specification disclose a blockchain data processing method, apparatus, device, and system. A request for transitioning a state of a contract stored at a blockchain system is received at a plurality of blockchain nodes of the blockchain system. The request includes signature data of at least one state participant of the contract. The contract is associated with a pre-determined number of participants. The signature data is verified at a blockchain node. The verification is based on at least one public key corresponding to the at least one state participant. A determination is made whether the signature data of the at least one state participant is verified. In response to determining that the signature data of the at least one state participant is verified, a new contract state defined in the request is confirmed. The pre-determined number of participants is pre-determined in the contract.

Abstract: A preset alert trigger event associated with a wealth management application operated on an electronic device is detected. In response to detecting the preset alert trigger event, the electronic device obtains a physiological characteristic parameter characterizing an emotion of a target user. The electronic device determines that a preset normal emotion fluctuation condition is not satisfied according to the physiological characteristic parameter. In response to determining that the normal emotion fluctuation condition is not satisfied, a risk alert on a wealth management action of the target user performed in the wealth management application is output.

Abstract: Methods, systems, and devices, including computer programs encoded on computer storage media, for data processing are provided. One of the methods includes: receiving a query parameter; obtaining query result data from each of one or more predetermined data sources according to the query parameter; converting the query result data into target reliable data conforming to a predetermined data reliability protocol; and sending the target reliable data to a blockchain node.

Abstract: This specification discloses an information presentation method and device. The method includes: determining at least one display object on a display page; obtaining information related to the at least one display object; and presenting the information related to the display object. At least part of a presentation area of the information overlaps with a display area of the related display object.

Abstract: Disclosed methods, systems, and apparatus, include computer programs encoded on computer storage media, for performing allocation of M resources among N users into K pools by solving a knapsack problem (KP) using a distributed computing system. The method includes: receiving data representing K global constraints and L local constraints of the KP; transforming the KP into a dual problem using K dual multipliers; decomposing the dual problem into N sub-problems; performing two or more iterations in solving the dual problem, wherein in one iteration, for each dual multiplier corresponding to a global constraint corresponding to a pool: determining an updated dual multiplier for the global constraint corresponding to the pool to be a non-negative threshold; and computing M decision variables of each of the N users corresponding to the updated dual multiplier in solving each of the N sub-problems corresponding to the each of the N users.

Abstract: A blockchain-based data processing system may comprise: a transaction-side blockchain node and a server-side blockchain node on a blockchain network maintaining a blockchain. The transaction-side blockchain node may be configured to: create a transaction data structure based on an Unspent Transaction Output (UTXO) model, consolidate transaction data of a transaction according to the transaction data structure to generate shared transaction data, execute a smart contract of the transaction-side blockchain node to automatically determine a to-be-settled commission amount, update the shared transaction data according to the to-be-settled commission amount, collect the updated shared transaction data according to a preset condition, and send a to-be-settled transaction processing request comprising the updated shared transaction data to the server-side blockchain node.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for verifiable-claim issuance. One of the methods includes: receiving, from a first entity, a request for creating a verifiable claim (VC) for a decentralized identifier (DID) associated with a second entity; obtaining, in response to receiving the request, a digital signature associated with the first entity; and generating the VC based on the received request and the obtained digital signature.

Abstract: A method for displaying a digital object identifier (DOI) is provided. The method includes receiving, by a server, a display instruction sent by a first device, wherein the display instruction is sent to the server after the first device receives a scan instruction to scan the DOI; determining a second device associated with the first device; and sending the display instruction to the second device, wherein the second device displays the DOI after receiving the display instruction.

Abstract: Disclosed herein are methods, devices, and apparatuses, including computer programs stored on computer-readable media, for testing signature verification for a blockchain system. One of the methods includes: obtaining a testing configuration from a configuration file, wherein the testing configuration specifies a cryptography algorithm used in the blockchain system, a group of one or more private keys corresponding to the cryptography algorithm, and a predetermined execution result based on the cryptography algorithm and the group of one or more private keys; signing a transaction, by encrypting data representing the transaction based on the cryptography algorithm and the group of one or more private keys, to generate one or more signed transactions; sending the one or more signed transactions to the blockchain system and receiving an execution result from the blockchain system; and determining whether the predetermined execution result is satisfied based on the execution result.

Abstract: During operation, a first node coupled to the blockchain sends a transaction confirmation request for a target transaction to a second node, the transaction confirmation request comprising transaction data associated with the target transaction. The first node receives a transaction confirmation response from the second node, the transaction confirmation response comprising a first data block comprising at least an identifier of the second node, first encoded transaction data generated based on a predetermined encoding scheme, and a first confirmation result. The first node generates a second data block comprising at least an identifier of the first node, second encoded transaction data generated based on the predetermined encoding scheme, and a second confirmation result; and in response to determining that each of the first confirmation result and the second confirmation result indicates that the target transaction is confirmed, stores the first data block and the second data block in the blockchain.

Abstract: The present specification discloses a service authorization method, apparatus and device.

Abstract: In an implementation, processing blockchain-based data is described. Data to be stored in a blockchain network is received at one or more processing devices of a blockchain node. A determination is made that an attribute of the data is of a particular type. In response to determining that the attribute of the data is of the particular type, a digest representing the data is generated. The digest is smaller in size than the data. The data is stored at a storage location in accordance with a mapping relationship between the digest and a first identifier of the data. An encrypted version of the digest is generated, by the one or more processing devices for storage on the blockchain network, using a private key of a public-private key pair corresponding to a second identifier of the data.

Abstract: Disclosed herein are methods, devices, and apparatuses, including computer programs stored on computer-readable media, for establishing communication between a first node and a second node in a blockchain system. One of the methods includes: the first node providing a node identifier of the first node to the second node and receiving a node identifier of the second node from the second node, to cause a first communication session to be established between the first node and the second node; the first node determining whether a second communication session exists between the first node and the second node; and in response to a determination that the second communication session exists between the first node and the second node, terminating one of the first communication session and the second communication session based on the node identifier of the first node and the node identifier of the second node.

Abstract: Implementations of the present specification provide a method for deploying a smart contract. According to one implementation the method includes: receiving a transaction request for invoking a first contract; obtaining a first instruction code and a function index table, wherein the function index table is used to indicate a memory address of an instruction code corresponding to each of import and export functions in the first contract; determining a first memory address corresponding to the invocation function based on the function index table; and executing the first instruction code in the first memory address based on the determined first memory address.

Abstract: One or more implementations of the present specification provide a blockchain-based data authorization method and apparatus. The method can include receiving, by a blockchain node, an authentication transaction submitted by a privacy computing platform, where the authentication transaction queries whether a data user has obtained authorization of target data possessed by a data owner, and in response to determining that the data user has obtained authorization of the target data, executing, by the blockchain node, a smart contract invoked by the authentication transaction to provide an authorization token to the privacy computing platform that instructs the privacy computing platform to obtain the target data, and send a computational result of one or more predetermined computational operations based on the target data to the data user.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for parallel-processing blockchain transactions are provided. One of the methods includes: obtaining a plurality of candidate transactions for adding to a blockchain; grouping the candidate transactions into one or more transaction groups; creating one or more copies of at least a portion of a data structure of a latest block of the blockchain; associating the one or more transaction groups respectively with the one or more copies of the data structure; executing the candidate transactions in each of the transaction groups and updating the associated copies of the data structure; and merging the updated copies of the data structure to obtain at least a portion of a new data structure of a new block to add to the blockchain.

Abstract: Implementations of the present specification provide article damage evaluation methods and apparatuses. In one aspect, the method includes: determining, by a terminal device, that a photographing device is in an active state; responsive to determining that the photographing device is in the active state, identifying, from a field of view of the photographing device, a particular surface region of the article that encompasses the damage to the article; obtaining an image of the particular surface region using the photographing device; determining surface structure information and surface material information of the surface region of the article using one or more infrared emitters and one or more infrared receivers; and generating, from the image, the surface structure information, and the surface material information, and based on a predetermined damage evaluation model, an output specifying a degree of the damage to the article.