Private Set Intersection Protocol that Rewards Participants

Core Concepts

A novel multi-party Private Set Intersection (PSI) protocol, called "Anesidora", that rewards parties who contribute their private input sets to the protocol.

Abstract

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.

Stats

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.

Quotes

"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)."

Key Insights Distilled From

Earn While You Reveal: Private Set Intersection that Rewards Participants

by Aydin Abadi at arxiv.org 04-29-2024

https://arxiv.org/pdf/2301.03889.pdf

Deeper Inquiries

How can the reward mechanism proposed in Anesidora be extended to other types of multi-party computation beyond PSI

The reward mechanism proposed in Anesidora can be extended to other types of multi-party computation beyond PSI by incorporating similar incentive structures in different protocols. For example, in secure multiparty computation scenarios where parties collaborate to perform computations on sensitive data without revealing individual inputs, a reward system can be implemented to encourage active participation. This could involve compensating parties for contributing their computational resources, sharing data, or maintaining the security of the protocol. By introducing incentives, parties are motivated to engage in the protocol, leading to increased participation and collaboration.

What are the potential drawbacks or limitations of the Anesidora protocol, and how can they be addressed

While the Anesidora protocol introduces a novel approach to incentivizing participation in Private Set Intersection protocols, there are potential drawbacks and limitations that need to be considered. One limitation is the complexity of implementing and managing the reward system, including determining fair compensation levels and ensuring that rewards are distributed accurately. Additionally, there may be concerns about the privacy and security implications of introducing a payment mechanism into secure computation protocols. To address these limitations, robust security measures, transparent reward mechanisms, and thorough auditing processes can be implemented to safeguard the integrity and privacy of the protocol. Furthermore, continuous monitoring and evaluation of the reward system can help identify and mitigate any potential issues or vulnerabilities.

What are the broader implications of incentivizing participation in secure multi-party computation protocols, and how might this impact the adoption and real-world use of such protocols

The incentivization of participation in secure multi-party computation protocols has broader implications for the adoption and real-world use of such protocols. By introducing reward mechanisms, parties are encouraged to actively engage in collaborative computations, leading to increased trust, cooperation, and efficiency in secure multiparty settings. Incentives can also attract a wider range of participants, including individuals and organizations, to contribute their resources and expertise to secure computation tasks. This can result in the development of more robust and diverse applications of secure multi-party computation in various domains, such as healthcare, finance, and data analytics. Overall, incentivizing participation can accelerate the adoption of secure multi-party computation protocols, driving innovation and enhancing the practicality and scalability of secure collaborative computing solutions.