V-EPTD: A Verifiable and Efficient Scheme for Privacy-Preserving Truth Discovery

Privacy-preserving truth discovery has been researched from many perspectives in the past few years. However, the complex iterative computation and multi-user feature makes it challenging to design a verifiable algorithm for it. In this paper, we propose a novel scheme named V-EPTD that not only protects the privacy information but also verifies the computing in truth discovery. The proposed technique adopts a threshold paillier cryptosystem to solve the multi-user problem so that all parties encrypt the data with the same public key while being unable to decrypt the ciphertext if there are not enough parties. V-EPTD also transforms complex iterative computation into polynomials, uses linear homomorphic hash, and commitment complete verification. The experimentation and analysis show that V-EPTD has good performances for users, verifiers, and the server, both in communication overhead and computation overhead.