Conceitos Básicos
A novel multi-party Private Set Intersection (PSI) protocol, called "Anesidora", that rewards parties who contribute their private input sets to the protocol.
Resumo
The key highlights and insights of the content are:
Private Set Intersection (PSI) protocols always reveal something about the private input sets of the participating parties, and in various PSI variants, not all parties receive or are interested in the result. However, the literature has assumed that parties who do not receive or are not interested in the result still contribute their private input sets to the PSI for free, although doing so would cost them their privacy.
The authors propose a novel multi-party PSI protocol called "Anesidora" that rewards parties who contribute their private input sets to the protocol. Anesidora is efficient, relying on symmetric key primitives, and its computation and communication complexities are linear with the number of parties and set cardinality.
Anesidora remains secure even if the majority of parties are corrupted by active colluding adversaries. The authors develop Anesidora in a modular fashion, first proposing the notion of "PSI with Fair Compensation" (PSI^FC) and devising the first construction called "Justitia" that realizes this notion.
PSI^FC ensures that either all parties get the result or, if the protocol aborts in an unfair manner (where only dishonest parties learn the result), then honest parties will receive financial compensation. Justitia is the first fair multi-party PSI protocol.
The authors then enhance PSI^FC to the notion of "PSI with Fair Compensation and Reward" (PSI^FCR) and develop Anesidora that realizes this notion. PSI^FCR ensures that honest parties are rewarded regardless of whether all parties are honest, or a set of them aborts in an unfair manner, and are compensated in the case of an unfair abort.
The authors also propose a new primitive called "unforgeable polynomial" that is used in the construction of Justitia and Anesidora.
Estatísticas
Anesidora's computation and communication complexities are linear with the number of parties and set cardinality.
Justitia is the first fair multi-party PSI protocol.
Citações
"Anesidora is in Greek and Roman mythology an epithet of several goddesses. It means sender of gifts. We call our protocol which sends rewards (or gifts) to honest parties Anesidora."
"To date, the literature has not answered the above question. The literature has assumed that all parties will participate in a PSI for free and bear the privacy cost (in addition to computation and computation overheads imposed by the PSI)."