Research On File Attribute-aware Data Security Deduplication Strategy

Secure deduplication technology can not only ensure the confidentiality of data,but also eliminate a large amount of duplicated data in massive data,thus effectively reducing the cost of data storage and transmission.However,secure deduplication technology is vulnerable to brute-force-attack because of the certainty of encryption process and key.Existing secure deduplication methods mainly focus on data security,but failed to improve the overall performance including high deduplication rate and low computing overhead.To overcome the shortcomings of existing methods,this paper proposes C-Dep,a file attribute-aware secure deduplication strategy.C-Dep adopts different secure deduplication methods for files of different sizes and types.For small files that prefer security,an optimized Dup LESS-Multi method based on the server-aided,chunk-level secure deduplication method(Dup LESS-Chunk)is proposed.Dupless-Multi combines file and block-level deduplication to provide the highest security guarantees without sacrificing the system performance or deduplication rate significantly.For large files,a convergent encryption method based on random key,RDep,is proposed to maximize the deduplication rate while reducing the cost of encryption and transmission by performing encryption-afterdeduplication.For medium-sized files,the user-aided method Sec Dep is adopted to ensure high security and deduplication rate with low computing overhead.The boundaries of classifying different files can be set manually to better fit specific application scenarios.Besides,C-Dep can fine-tune the boundaries dyanmically according to file type and realtime deduplication rate to further improve overall performance.In the experiment of emulating backing up data to the cloud,the results show that CDep can improve the overall performance while ensuring data security in deduplication.Specifically,compared to the Dup LESS-Chunk method,the Dup LESS-Multi method of CDep proposed for small files can shorten the time of backing up 50 64KB-files by an average od 87.77% while preserving the same deduplication rate.Compared with Sec Dep,the RDep method of C-Dep proposed for large files improves the deduplication rate by an average of1.21 x and decrease backup time by an average of 12.56%.The complete C-Dep strategy improves the deduplication rate by an average of 35.7% while only incuring 1.23% of extra backup time when compared to Sec Dep,and decreasing the backup time by 99% with only a loss of 2.9% deduplication rate when compared to Dup LESS-Chunk.