1. Shared-Dining: Broadcasting Secret Shares Using Dining-Cryptographers Groups
- Author
-
Juri Dispan, David Mödinger, Franz J. Hauck, Institute of Distributed Systems, Universität Ulm - Ulm University [Ulm, Allemagne], Miguel Matos, Fabíola Greve, TC 6, and WG 6.1
- Subjects
FOS: Computer and information sciences ,050101 languages & linguistics ,Security analysis ,Dining cryptographers problem ,Computer Science - Cryptography and Security ,Computer science ,Throughput ,02 engineering and technology ,Broadcasting ,Computer security ,computer.software_genre ,Secret sharing ,Computer Science - Networking and Internet Architecture ,[INFO.INFO-NI]Computer Science [cs]/Networking and Internet Architecture [cs.NI] ,Privacy protocol ,0202 electrical engineering, electronic engineering, information engineering ,0501 psychology and cognitive sciences ,[INFO]Computer Science [cs] ,Communication source ,Network protocol ,Peer-to-Peer networking ,Networking and Internet Architecture (cs.NI) ,business.industry ,05 social sciences ,Flooding (computer networking) ,Dining cryptographers ,020201 artificial intelligence & image processing ,business ,computer ,Cryptography and Security (cs.CR) ,Anonymity - Abstract
A k-anonymous broadcast can be implemented using a small group of dining cryptographers to first share the message, followed by a flooding phase started by group members. Members have little incentive to forward the message in a timely manner, as forwarding incurs costs, or they may even profit from keeping the message. In worst case, this leaves the true originator as the only sender, rendering the dining-cryptographers phase useless and compromising their privacy. We present a novel approach using a modified dining-cryptographers protocol to distributed shares of an (n,k)-Shamir's secret sharing scheme. Finally, all group members broadcast their received share through the network, allowing any recipient of k shares to reconstruct the message, enforcing anonymity. If less than k group members broadcast their shares, the message cannot be decoded thus preventing privacy breaches for the originator. Our system provides (n-|attackers|)-anonymity for up to k-1 attackers and has little performance impact on dissemination. We show these results in a security analysis and performance evaluation based on a proof-of-concept prototype. Throughput rates between 10 and 100 kB/s are enough for many real applications with high privacy requirements, e.g., financial blockchain system., 16 pages, 5 figures
- Published
- 2021