Aimed at the problem that existing RFID (Radio Frequency Identification) group proof protocols are inefficient and easily encounter many attacks like replay, tracking and so on, this paper proposed a new group proof protocol based on secret key-sharing tree. This protocol designed a new secret group-proofing key construction based on secret key sharing scheme. The group-proofing key was divided many times into many sub-keys to creat a key tree. This method increased the complexity of the construction of the secret key, increased the difficulty of that attackers attempt to recover the group key and increased the security of tag's group proof. The reader interacts with each tag only once to authenticate its validity and collect the group-proof information. This protocol enormously increases the proof efficiency. Compared to the existing protocols such as Yoking-Proofs, ECC-based and Tree-based, this protocol has better security and higher efficiency.
Due to individual differences in the ability, learning objectives and learning time of the learners,a learning resource recommendation method based on Particle Swarm Optimization (PSO) algorithm was proposed to provide the learner with a personalized digital curriculum. The knowledge structure chart was constructed applying concept map and knowledge structure. The learning objectives and the ability of the learner were analyzed based on item response theory. The PSO algorithm was adopted to select the appropriate e-learning materials from a mass of candidate materials and the adaptive e-course was composed and recommended. The learning time limit was considered while initializing particles, and some unnecessary particles were filtered out to improve the efficiency of the algorithm. When determining the optimal solution, the Sigmoid function was used to fix the particle update velocity to ensure it effective. The experimental results show that with the increase of the number of iterations, the difference between the recommended content and the learner goal is 0. The difference between the recommended curriculum and the learner ability is 0.6, and the overall difference is 0.25.It shows that the convergency and efficiency of the proposed method and the selected learning materials can meet the demands of different learners.