RESUMEN
The development of information technology has brought great convenience to our lives, but at the same time, the unfairness and privacy issues brought about by traditional centralized systems cannot be ignored. Blockchain is a peer-to-peer and decentralized ledger technology that has the characteristics of transparency, consistency, traceability and fairness, but it reveals private information in some scenarios. Secure multi-party computation (MPC) guarantees enhanced privacy and correctness, so many researchers have been trying to combine secure MPC with blockchain to deal with privacy and trust issues. In this paper, we used homomorphic encryption, secret sharing and zero-knowledge proofs to construct a publicly verifiable secure MPC protocol consisting of two parts-an on-chain computation phase and an off-chain preprocessing phase-and we integrated the protocol as part of the chaincode in Hyperledger Fabric to protect the privacy of transaction data. Experiments showed that our solution performed well on a permissioned blockchain. Most of the time taken to complete the protocol was spent on communication, so the performance has a great deal of room to grow.
RESUMEN
A polyhedral oligomeric silsesquioxane (POSS)-based hybrid triblock copolymer - methyl methacrylate-b-perfluoroalkylethyl methacrylate-b-methacrylisobutyl polyhedral oligomeric silsesquioxane (PMMA-b-PFMA-b-PMAPOSS) was synthesized via an atom transfer radical polymerization (ATRP) method. The self-assembly behavior of triblock copolymers in selective solvents of tetrahydrofuran (THF) and trichlorotrifluoroethane (F113) was studied using dissipative particle dynamics (DPD) simulation. The effects of the block sequence and volume ratio of F113/THF were discussed. The aggregate morphology and size were also characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The simulation results showed that the spherical micelle with core-shell-corona or core-mixed shell structure could be formed and the micelle size increased with the F113 content, which was in qualitative agreement with the experimental results. The DPD simulation revealed the dynamic process of the formation of aggregates at the mesoscopic scale, which can be considered as an adjunct to experiments and provides other valuable information for the experiments.