Abstract: Computer-implemented methods, apparatuses and systems for obtaining data authorization are described. In an example method, a first computing node in a trusted computing center receives an authentication request from a first provider. Authentication information is returned to the first provider, where the authentication information comprises a first code hash of a first computing logic running in the first computing node. A channel establishment request sent by the first provider is received after determining that the first computing node passes trusted authentication and the first code hash passes correctness verification. A first trusted channel is established between the first provider and the first computing node according to the channel establishment request. A target encryption key is received through the first trusted channel, thereby authorization to perform computation on a target encrypted shard corresponding to the target encryption key based on the first computing logic is obtained.

Abstract: Embodiments of this specification provide methods and apparatuses for data privacy protection. An embodiment of the methods comprises receiving, by a first party from a second party, an encrypted integrated vector, determining an encrypted result vector based on the original matrix and the encrypted integrated vector, determining a data processing result based on the encrypted result vector, and sending the data processing result to the second party for the second party to obtain a multiplication calculation result of the original matrix and the n original vectors based on the data processing result.

Abstract: In accordance with the present invention, the rheology of an aqueous fluid is modified by a method which comprises adding to said aqueous fluid an amount of a viscoelastic composition sufficient to form a viscoelastic fluid. The viscoelastic composition of the invention comprises a combination of i) at least one alkyl amido quaternary amine, and ii) at least one coadditive that comprises a C8-24 linear alkyl and/or alpha-olefin sulfate and/or sulphonate.