Decentralized solutions are emerging as promising candidates to overcome the privacy risks associated with centralized data services. Such solutions suffer however from their own range of privacy vulnerabilities, arising from untrusted and malicious peers. In this paper, we consider the emblematic problem of privacy-preserving decentralized averaging, and propose a novel gossip protocol that exchanges noise for several rounds before starting to exchange actual data. This makes it hard for an honest but curious attacker to know whether a user is transmitting noise or actual data. Our protocol and analysis do not assume a lock-step execution, and demonstrate improved resilience to colluding attackers. We prove the correctness of this protocol as well as several privacy results. Finally, we provide simulation results about the efficiency of our averaging protocol.
complete documentdoi: http://doi.org/10.1007/978-3-030-34992-9_4 (publisher's link)
Copies / Update: Please contact me by email if you wish to obtain a copy of a paper that is not available on line.