Abstract: A system for enabling escrow-free, secure, and convenient atomic asset swaps between blockchains are provided. In detail, when any group of users reach an agreement on the content of cross-chain asset swap transactions, each participant creates an individual signature on the content of each transaction, employs a reversible signature aggregate function to produce an aggregate signature from all his/her individual signatures, and optionally generates a proof to prove the relationship between the aggregated signature and the transaction contents. Sequentially, all the participants exchange these aggregated signatures and optional proofs. Once a participant publishes one of his/her individual signature, the other parties can use both signatures—one from the sender and the other from the recipient—to construct a complete transaction. Once a transaction is broadcast, its corresponding transactions are constructed, and broadcast.

Abstract: A fault-tolerant asset transferring method is provided to prevent financial losses caused by human errors, specifically unintentional mistakes made by the payer. The system introduces a new definition for blockchain transaction parameters, allowing for multi-input transactions. Each payment transaction includes the payee's signature for confirmation and the payer's signature. In addition, a system is designed to handle multi-input asset transfer transactions which incorporate the payer's confirmation. Upon reaching an agreement on the transaction content, each participant generates an independent off-chain signature on the transaction's content. In the event that participants generate a signature on the erroneous content of a transaction, the transaction will be accepted in the blockchain with very low probability due to transaction validation.

Abstract: Method, device and system for building blockchain-based secure aggregation in federated learning with data removal are provided. The method includes: selecting a first quantity of client nodes, to participate in an i-th iteration; sending a list of the selected client nodes to each of the first quantity of client nodes; acquiring model training information transmitted by each of a second quantity of client nodes, the model training information being transmitted in a form of cypher text, where the cypher text is generated by performing homomorphic encryption on the model training information based on pairwise seeds computed for each of the first quantity of client nodes from a symmetric bivariate polynomial and a private seed computed from asymmetric bivariate polynomial; aggregating the cypher text to obtain an aggregate result; and broadcasting a list of the second quantity of client nodes and the aggregate result via a blockchain.

Abstract: A method and system for atomic, consistent and accountable cross-chain rewriting are provided. The method is applicable for a blockchain network comprising a set of correlative blockchains. The method includes: in response to a user redaction proposal for any of the correlative blockchains, generating a set of correlative redaction proposals that involve all related transactions depending on a target transaction to be redacted by the user redaction proposal, based on a transaction dependency graph representing a dependency relationship of transactions, wherein at least one of the transactions in the transactions is to be redacted by the user redaction proposal; validating the user redaction proposal and the correlative redaction proposals, according to a predefined cross-chain redaction policy; calling the correlative blockchains for executing the validated redaction proposals; and updating the transaction dependency graph in response to execution of the validated redaction proposals.

Abstract: The application provides a structured light module and an autonomous mobile device. The structured light module includes a first camera and line laser emitters for collecting a first environmental image containing laser stripes generated when the line laser encounters an object. The structured light module can also capture a visible light image through a second environmental image that does not contain laser stripes. Both the first and second environmental images can help to detect more accurate and richer environmental information, expanding the application range of laser sensors.

Abstract: Disclosed are a neural network model update method and device, and a computer storage medium. The method includes: randomly generating a preset number of sub-neural network models as nodes in a blockchain; using a ring signature to share a local data set in the blockchain, and uniformly dividing a data set in the blockchain to generate a training set and a test set; training each node through the training set to generate a trained model, packaging the trained model as a model transaction and sharing the model transaction in the blockchain; using the test set selected by voting to test the model transaction and generating a test result; when the test result is greater than a benchmark evaluation, taking the sub-neural network model corresponding to the test result as a valid vote; and voting a previous block corresponding to the valid vote, selecting a consistent block, and updating all nodes.

Abstract: Disclosed are a data file distribution method and equipment, a smart device and a computer storage medium. The method includes the following operations: sorting data files according to an access frequency of each data file, a sorting mode including an ascending order or a descending order; dividing the data files into at least two data blocks according to a sorted order, numbers of data files in the at least two data blocks being equal; merging the data files in each of the at least two data blocks in pairs to update the data files; sorting the updated data files according to the access frequency of each data file until the numbers of the data files are equal to numbers of distributed nodes; and placing the data files on corresponding distributed nodes.

Abstract: Disclosed are a neural network model update method and device, and a computer storage medium. The method includes: randomly generating a preset number of sub-neural network models as nodes in a blockchain; using a ring signature to share a local data set in the blockchain, and uniformly dividing a data set in the blockchain to generate a training set and a test set; training each node through the training set to generate a trained model, packaging the trained model as a model transaction and sharing the model transaction in the blockchain; using the test set selected by voting to test the model transaction and generating a test result; when the test result is greater than a benchmark evaluation, taking the sub-neural network model corresponding to the test result as a valid vote; and voting a previous block corresponding to the valid vote, selecting a consistent block, and updating all nodes.

Abstract: A method for pairing a plurality of devices in the context of internet of things (IoT), including: connecting power supplies of the plurality of devices to a same power source, wherein the plurality of devices includes an initiator device and a responder device; synchronizing clocks of the initiator device and the responder device; switching the power source off and on for a plurality of times n; recording time stamps S(T)={T1, T2, T3, . . . Tn} corresponding to time stamps when the initiator device and the responder device switch off in response to switching off of the power source; and performing the pairing of the initiator device and the responder device if each of the initiator device time stamps is within a predefined delay tolerance of a corresponding time stamp of the responder device time stamps, otherwise rejecting the pairing of the initiator device and the responder device.

Abstract: A method for pairing a plurality of devices in the context of internet of things (IoT), including: connecting power supplies of the plurality of devices to a same power source, wherein the plurality of devices includes an initiator device and a responder device; synchronizing clocks of the initiator device and the responder device; switching the power source off and on for a plurality of times n; recording time stamps S(T)={T1, T2, T3, . . . Tn} corresponding to time stamps when the initiator device and the responder device switch off in response to switching off of the power source; and performing the pairing of the initiator device and the responder device if each of the initiator device time stamps is within a predefined delay tolerance of a corresponding time stamp of the responder device time stamps, otherwise rejecting the pairing of the initiator device and the responder device.

Abstract: A method for processing a data request is performed by an access device, and includes receiving, from a user terminal, the data request including data information of target data, obtaining the data information from the data request, searching for a storage device identifier and first authentication information, based on the data information, and sending the first authentication information and the data information, to a storage device corresponding to the storage device identifier, to enable the storage device to perform authentication on the first authentication information, and to enable the storage device to, in response to the authentication succeeding, obtain the target data indicated by the data information. The method further includes receiving, from the storage device, the target data, and sending the target data to the user terminal, to respond to the data request.

Abstract: A method, an apparatus, and a computer program product for remote authentication are disclosed. The methods are based on exchanging of signals representing remote party's biometrics information (such as acoustic waveforms) and have application in secure telephony or video-conferencing communications over open networks. The apparatus includes a speech encoding/decoding module (632), a control module (636), an encryption/decryption module (640), a key generator (650), a Diffie Hellman key exchange system (660), a timer module (670) for measuring time between a challenged statement and a corresponding response statement, an input/output (I/O) module (680) for transmitting and receiving data via a communications channel 610.