BL-MLE: Block-level message-locked encryption for secure large file deduplication

• Main Authors: CHEN, Rongmao, MU, Yi, YANG, Guomin, GUO, Fuchun
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2015
• Subjects: deduplication; Message-locked encryption; proof of ownership; proof of storage; Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/7358; https://ink.library.smu.edu.sg/context/sis_research/article/8361/viewcontent/BL_MLE_Block_Level_Message_Locked_Encryption_for_Secure_Large_File_Deduplication.pdf
• Institution: Singapore Management University

Deduplication is a popular technique widely used to save storage spaces in the cloud. To achieve secure deduplication of encrypted files, Bellare et al. formalized a new cryptographic primitive named message-locked encryption (MLE) in Eurocrypt 2013. Although an MLE scheme can be extended to obtain secure deduplication for large files, it requires a lot of metadata maintained by the end user and the cloud server. In this paper, we propose a new approach to achieve more efficient deduplication for (encrypted) large files. Our approach, named block-level message-locked encryption (BL-MLE), can achieve file-level and block-level deduplication, block key management, and proof of ownership simultaneously using a small set of metadata. We also show that our BL-MLE scheme can be easily extended to support proof of storage, which makes it multi-purpose for secure cloud storage.