Research On Data Traceability Technology Based On Blockchain And Digital Watermark

With the increasing demand for data sharing,the security requirements of the data sharing are also constantly improving.Data may suffer leakage problems during the sharing process.The traceability of data leakage has become one of the research hot topic.Blockchain and digital watermark are commonly used technologies for data traceability.The work of the thesis focuses on the scenarios of data sharing within the system and data distribution outside the system.In view of the shortcomings of the existing traceability methods,the thesis research the methods based on watermark and blockchain technology to support the accountability of data leakage traceability in data distribution and sharing.The main work of the thesis includes:(1)Existing provenance based on blockchain lack of verification of node permission.Most methods treat transactions as independent records and fail to associate them as a whole which increases the cost of traceability of leaks.Aiming at above issues,a blockchain-based data recording and provenance structure is proposed.The file permission list is designed to manage node permission.Standardize the data sharing process and recording form within the system,and traceability process in case of data leakage is proposed.Modifying the transaction structure to link each other by adding pre-transaction hash value field to reduce the traceability cost in case of data leakage.(2)Existing digital watermark traceability methods are difficult to balance the availability of data classification and watermark security.To solve problem above,a range projection-based watermark traceability algorithm is proposed.The concept of interval mapping is introduced.Mapping attribute values to intervals and floating select value within the interval to realize watermark embedding.By embedding a watermark into each attribute value,achieving the maintenance of the availability of data classification and the security of the watermark,supporting effective traceability when part of the data is leaked.Theoretical analysis and experimental results verify the effectiveness of proposed methods.