Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing data element stored in a blockchain network. One of the methods includes receiving a request from a client computing device to store a data element into the blockchain network by a blockchain data element processing server. The blockchain data element processing server determines whether the client computing device is authorized to store the data element into the blockchain network and whether the data element is a sensitive data element. If the client computing device is authorized to store the data element into the blockchain network and the data element is not a sensitive data element, the blockchain data element processing server stores the data element that is encrypted using an encryption algorithm into the blockchain network.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing housing scores of residents using a smart contract executing within a blockchain network. The method includes: receiving, by a node of the blockchain network, a smart contract that defines operations for managing housing scores of residents, the operations including: a score inquiry operation, a score addition operation, a score deduction operation, a score redemption operation, and a score transfer operation; executing, by the node, one of the operations defined in the smart contract for managing a housing score of a specified resident; determining, by the node, if a current housing score of the specified resident triggers a reporting event; and in response to determining that the current housing score of the specified resident triggers the reporting event, reporting, by the node to the specified resident, the current housing score of the specified resident.

Abstract: This disclosure relates to storing and executing a smart contract in a blockchain. In one aspect, a method includes receiving a transaction request to conduct a transaction for storing a target smart contract in the blockchain. The target smart contract includes multiple logical methods. A query is made whether the target smart contract includes a first logical method that is the same as a second logical method in a stored smart contract that is stored in the blockchain. In response to determining that the target smart contract includes the first logical method that is the same as the second logical method in the stored smart contract, each logical method of the multiple logical methods that is not the same as a logical method previously stored in the blockchain and a mapping relationship between the first logical method and the second logical method is stored in the blockchain.

Abstract: Implementations of the present specification include storing a data item in a consortium blockchain; generating a first data digest based on the stored data item; sending the first data digest to verification nodes to cryptographically signs it and stores the signed first data digest in a public blockchain; receiving a request to retrieve the stored data item; retrieving the requested data item from the consortium blockchain; generating a second data digest based on the retrieved data item; sending the second data digest to verification nodes so that each verification node signs the second data digest; receiving the signed second data digests from the plurality of verification nodes; retrieving the signed first data digests from the public blockchain; determining that the signed first data digests match the signed second data digests; and sending a response indicating the stored data item is unchanged to the request to retrieve the stored data item.

Abstract: Implementations of the present specification include storing a data item in a consortium blockchain; generating a first data digest based on the stored data item; sending the first data digest to verification nodes to cryptographically signs it and stores the signed first data digest in a public blockchain; receiving a request to retrieve the stored data item; retrieving the requested data item from the consortium blockchain; generating a second data digest based on the retrieved data item; sending the second data digest to verification nodes so that each verification node signs the second data digest; receiving the signed second data digests from the plurality of verification nodes; retrieving the signed first data digests from the public blockchain; determining that the signed first data digests match the signed second data digests; and sending a response indicating the stored data item is unchanged to the request to retrieve the stored data item.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for product promotion using a smart contract in a blockchain network. The method includes: receiving, by a node of a blockchain network, a creation request to create a promotion event, wherein: the promotion event is associated with multiple promotion codes and a pair of a private key and a public key, and the creation request includes the public key and a digital signature generated using the private key; determining, by the node and based on the public key and the digital signature, validity of the creation request; and in response to determining that the creation request is valid, registering, by the node, the promotion event in the blockchain network using a smart contract without storing the multiple promotion codes in the blockchain network.

Abstract: Implementations of the present specification include storing a data item in a consortium blockchain; generating a first data digest based on the stored data item; sending the first data digest to verification nodes to cryptographically signs it and stores the signed first data digest in a public blockchain; receiving a request to retrieve the stored data item; retrieving the requested data item from the consortium blockchain; generating a second data digest based on the retrieved data item; sending the second data digest to verification nodes so that each verification node signs the second data digest; receiving the signed second data digests from the plurality of verification nodes; retrieving the signed first data digests from the public blockchain; determining that the signed first data digests match the signed second data digests; and sending a response indicating the stored data item is unchanged to the request to retrieve the stored data item.

Abstract: Implementations of the present specification include storing a data item in a consortium blockchain; generating a first data digest based on the stored data item; sending the first data digest to verification nodes to cryptographically signs it and stores the signed first data digest in a public blockchain; receiving a request to retrieve the stored data item; retrieving the requested data item from the consortium blockchain; generating a second data digest based on the retrieved data item; sending the second data digest to verification nodes so that each verification node signs the second data digest; receiving the signed second data digests from the plurality of verification nodes; retrieving the signed first data digests from the public blockchain; determining that the signed first data digests match the signed second data digests; and sending a response indicating the stored data item is unchanged to the request to retrieve the stored data item.