A method for data exchange on a communication network, operating according to a protocol, and including a transmission bus, a first node and a second node. The first node carries out the steps of: constructing a first and a second data frame which transport first and second information data; calculating a first message authentication code as a function of the first and the second information data; constructing a third data frame which transports the first message authentication code; transmitting all of the data frames thus constructed. The second node carries out the steps of: receiving the first, the second and the third data frames; extracting the first and the second information data and the first message authentication code; calculating a second message authentication code as a function of the first and the second information data extracted; comparing the message authentication code extracted with the message authentication code calculated in order to verify the identity thereof.

A method for supporting sharing of travel history of travelers in airports includes receiving, by a trusted entity of the distributed ledger system, a registration request from a traveler via a traveler application. The registration request provides personal information of the traveler to the trusted entity. The method further includes generating, by the trusted entity, a public key for the traveler using an identity-based encryption mechanism and sending, from the trusted entity to the global identity blockchain, a registration transaction with respect to the traveler. The registration transaction comprises the public key of the traveler. The method further includes recording a travel history that includes all travel tickets of the traveler, wherein a Merkle tree of all the travel tickets of the traveler is generated. The Merkle tree has a Merkle root, and the Merkle root of the Merkle tree is stored in the global identity blockchain.

Disclosed are a method and a system for cross-chain data access of blockchain. According to the technical solution, an adapter is added between a service blockchain and a witness blockchain, a cross-chain initiation event and a cross-chain response event on a local service blockchain are registered to the witness blockchain by using the adapter, so as to provide query and push services of cross-chain events to other nodes on the local service blockchain, and trigger related operations on the local service blockchain according to the cross-chain events of the witness blockchain.

A data processing method and apparatus based on a blockchain network, and a computer device. The method includes acquiring a transaction request, the transaction request carrying transaction data and reference signature data corresponding to the transaction data; validating the transaction data and the reference signature data; determining a matching node device from a target node device if the transaction data and the reference signature data are validated, and acquiring a signing key of the matching node device; determining data to be signed according to the transaction data, and signing on the data to be signed using the signing key of the matching node device to obtain endorsement signature data; and transmitting the endorsement signature data to the management device, wherein the management device generates a transaction block according to the endorsement signature data and the transaction data.

A data processing method and apparatus based on a blockchain network, and a computer device. The method includes acquiring a transaction request, the transaction request carrying transaction data and reference signature data corresponding to the transaction data; validating the transaction data and the reference signature data; determining a matching node device from a target node device if the transaction data and the reference signature data are validated, and acquiring a signing key of the matching node device; determining data to be signed according to the transaction data, and signing on the data to be signed using the signing key of the matching node device to obtain endorsement signature data; and transmitting the endorsement signature data to the management device, wherein the management device generates a transaction block according to the endorsement signature data and the transaction data.

A method, an apparatus, a computer device, a storage medium, and a program product for processing data are provided, which belong to the technical field of artificial intelligence. The method includes: acquiring model training information transmitted by each of at least two edge node devices, the model training information being transmitted in a form of plaintext, and being obtained by the edge node device by training sub-models through differential privacy; acquiring, based on the model training information transmitted by each of the at least two edge node devices, the sub-models trained by each of the at least two edge node devices; and performing, based on a target model ensemble policy, model ensemble on the sub-models trained by the at least two edge node devices, to obtain a global model. This solution expands the manner of model ensemble while ensuring the data security, thereby improving the model ensemble effect.

The present invention realizes an electronic signature system with high security level in which abuse of a signature key by a system administrator is prevented. A user sets an authentication information conceived by the user himself to his/her own signature key stored in the tamper resistant device (5) via the terminal device (2). When digitally signing an electronic document, the user transmits his/her own encrypted authentication information to the tamper resistant device (5) through the terminal device (2) and asks for permission to use his/her signature key. The tamper resistant device (5) decodes the inputted authentication information, verifies the decoded authentication information, and allows the digital signing only if the correct authentication information is entered. As a result, the electronic signature system in which only a user having valid use authority for the signature key can digitally sign is built.

A cross-chain collaborative governance system is configured to perform collaborative service and control governance on cross-chain interoperation between application subchains in a cross-chain alliance. The cross-chain collaborative governance system includes: a cross-chain access application layer configured to make a first application subchain and a second application subchain access the cross-chain collaborative governance system; a credible cross-chain collaborative layer configured to provide collaborative service for cross-chain interoperation between the first application subchain and the second application subchain; and a credible cross-chain governance layer configured to perform control governance on the cross-chain interoperation between the first application subchain and the second application subchain.

A secure guest generates an updated image for the secure guest, and computes one or more measurements for the updated image. The secure guest provides the one or more measurements to a trusted execution environment and obtains from the trusted execution environment metadata for the updated image. The metadata is generated based on metadata of the secure guest and obtaining the one or more measurements.

A secure guest generates an updated image for the secure guest, and computes one or more measurements for the updated image. The secure guest provides the one or more measurements to a trusted execution environment and obtains from the trusted execution environment metadata for the updated image. The metadata is generated based on metadata of the secure guest and obtaining the one or more measurements.