Abstract: At present, the opacity of big data interaction and the unreasonable access form of data files lead to the problems of long storage delay and poor security in big data storage. We propose a dynamic secure storage technology of unstructured big data based on block chain. The multi-user rule scheduling model is constructed, the independent row vector and n-order matrix are generated by using the stored data packet, and the storage algorithm is designed based on the probability of column dissatisfaction rank. The public and private keys of block chain asymmetric encryption technology is used to realize transparent and complete data interaction and record the secondary information and data access forms. The distributed file system is introduced, which is effectively combined with Mongo DB non-relational database, and the unstructured big data can be stored safely.The simulation results show that the proposed method has an ideal storage rate, and ensures the integrity of big data. It is effective and practical.

Key words: blockchain, unstructured big data, dynamic secure storage, distributed file system, non-relational database