Space efficient revocable IBE for mobile devices in cloud computing

• Main Authors: QIN, Baodong, LIU, Ximeng, WEI, Zhuo, ZHENG, Dong
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2020
• Subjects: Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/5121; https://ink.library.smu.edu.sg/context/sis_research/article/6124/viewcontent/s11432_018_9455_5__1_.pdf
• Institution: Singapore Management University

Revocation capacity is one of the main properties for an identity-based encryption (IBE), as in practice users’ private keys are possibly leaked or expired. However, existing revocable IBE schemes usually lack of short keys. Recently, Lin et al. proposed a method to design space efficient revocable IBE scheme from non-monotonic key-policy attribute-based encryption scheme. But, it requires too many pairings (linear to the number of revoked users) to decrypt an IBE ciphertext. In this study, we overcome this problem by adopting the technique of server-aided revocation, recently proposed by Qin et al. in ESORICS 2015. The main contribution is a new server-aided revocable IBE scheme, which can largely shift decryption overhead from local users to an untrusted cloud computing server, and significantly reduce the complexities of PKG’s (Private-Key Generator) key update information and server’s long-term identity-based public information (also called long-term transformation keys) with the comparison of previous (server-aided) revocable IBE scheme.