A lightweight framework of Internet of Things (IoT) information sharing security based on blockchain technology was proposed to solve the problems of IoT's information sharing, such as source data susceptible to tampering, lack of credit guarantee mechanism and islands of information. The framework used double-chain pattern including data blockchain and transaction blockchain. Distributed storage and tamper-proof were realized on the data blockchain, and the registration efficiency was improved through a modified Practical Byzantine Fault Tolerance (PBFT). Resource and data transactions were realized on the transaction blockchain, the transaction efficiency was improved and privacy protection was realized through the improved algorithm based on partial blind signature algorithm. The simulation experiments were carried out to analyse, test and verify anti-attack capability, double-chain processing capacity and time delay. Simulation results show that the proposed framework has security, effectiveness and feasibility, which can be applied to most situations of the real IoT.

Influence maximization problem in micro-blog cannot be solved by simple user rank algorithm. To solve this problem, a greedy algorithm based on Extended Linear Threshold Model (ELTM) was proposed to solve Top-K problem in microblog. A concept of influence rate and a WIR (Weibo Influence Rank) algorithm were established to determine the user's influence by summarizing the key factors. Then, based on WIR values, an influence propagation model was proposed. After using greedy algorithm, the Top-K nodes were excavated. A simulation test based on Sina micro-blog was performed to validate the effectiveness of the proposed method. The result shows that the method outperforms the traditional algorithm.