Privacy-aware and Security-enhanced efficient Matchmaking Encryption

Abstract

Data sharing technologies enable users to outsource data and privately share information with arbitrary recipients without geographic barriers. However, existing efforts for secure data sharing are either inflexible, insufficiently-secure or inefficient. In this paper, we invent PS-ME, the first Privacy-aware and Security-enhanced efficient Matchmaking Encryption (ME) for flexible data sharing. To be more specific, we first formulate an identity-based broadcast matchmaking encryption (IB-BME) for one-to-many data sharing, which enables both participants to specify respective access policies to the encrypted data, such that the data can be revealed by multiple recipients in the case that both access policies are satisfied. In IB-BME, a general matchmaking transformation solution realizing one-to-many sharing is initialized. We also formulate the PS-ME with the general matchmaking transformation solution of IB-BME as the underlying approach, which in addition to featuring IB-BME's all desirable properties, enables efficient decryption, identity anonymity and CCA-security, where we address the open problem of ME regarding CCA-security (raised in CRYPTO'2019). Finally, the comprehensively rigorous security proofs indicate the security of the suggested methodologies. The experimental results are also shown to demonstrate their practicability and effectiveness.