Device-enhanced secure cloud storage with keyword searchable encryption and deduplication

• Main Authors: JIANG, Changsong, XU, Chunxiang, YANG, Guomin
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2024
• Subjects: Private key recovery mechanism; Public-key cryptosystems; DULCET; PEKS; Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/9796
• Institution: Singapore Management University

We observe that server-aided message-locked encryption (MLE) and server-aided public key encryption with keyword search (PEKS) can be integrated into one cloud storage system to support both deduplication and keyword search over encrypted outsourced data. However, the system is confronted with a potential key management problem: a user has to store her/his private key in all potential clients for data access, thereby leading to security concerns about key migration among different clients and key storage in multiple clients. To alleviate the problem, we present a device-aided private key recovery mechanism for public-key cryptosystems, which enables a user holding a personal device and a password to recover her/his private key in any client. Such recovery is accomplished with the combination of an oblivious protocol and short-authentication-string message authentication, which does not require any secure link between the device and a client while guaranteeing the security of the password and the private key. Based on the presented mechanism, we propose a device-enhanced secure cloud storage system with keyword searchable encryption and deduplication, dubbed DULCET. We analyze the security of DULCET and conduct a comprehensive performance evaluation, which shows that DULCET is secure and efficient.