Paper 2025/1108
Laconic PSI on Authenticated Inputs and Applications
Abstract
A common issue with using secure computation in practice is that its security does not place any restrictions on what an adversary can use as input in the protocol. In this work, we focus on the practically-motivated setting of (two-message, labeled) private set intersection (PSI), and advocate for a clean and versatile solution to this problem: PSI on authenticated inputs. Our central contributions are summarized as follows. - We formulate a novel definition of PSI on authenticated inputs that has the potential for use in several applications, from content moderation in end-to-end encrypted systems to watchlists in anonymous e-cash systems. - We design a concretely-efficient and laconic (i.e., the size of the receiver's message is independent of its set size) protocol for PSI on authenticated inputs. - We build on our PSI protocol to obtain the first laconic set pre-constrained group signature scheme, improving on that of Bartusek et al. (Eurocrypt 23). We also explore various optimizations to our basic protocol, including reducing the receiver's concrete run time, and a tradeoff between crs size and message size.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint.
- Contact author(s)
-
bartusek james @ gmail com
sanjamg @ berkeley edu
abhishek @ cs jhu edu
guruvamsi policharla @ gmail com - History
- 2025-06-13: approved
- 2025-06-12: received
- See all versions
- Short URL
- https://ia.cr/2025/1108
- License
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CC0
BibTeX
@misc{cryptoeprint:2025/1108, author = {James Bartusek and Sanjam Garg and Abhishek Jain and Guru-Vamsi Policharla}, title = {Laconic {PSI} on Authenticated Inputs and Applications}, howpublished = {Cryptology {ePrint} Archive, Paper 2025/1108}, year = {2025}, url = {https://eprint.iacr.org/2025/1108} }