DL-Extractable UC-Commitment Schemes

Behzad Abdolmaleki, Karim Baghery, Helger Lipmaa, Janno Siim, Michał Zajac

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We define a new UC functionality (DL-extractable commitment scheme) that allows committer to open a commitment to a group element g^x; however, the simulator will be able to extract its discrete logarithm x. Such functionality is useful in situations where the secrecy of x is important since the knowledge of x enables to break privacy while the simulator needs to know x to be able to simulate the corrupted committer. Based on Fujisaki's UC-secure commitment scheme and the Damgård-Fujisaki integer commitment scheme, we propose an efficient commitment scheme that realizes the new functionality. As another novelty, we construct the new scheme in the weaker RPK (registered public key) model instead of the CRS model used by Fujisaki.
Original languageEnglish
Title of host publicationApplied Cryptography and Network Security
EditorsRobert H. Deng, Valérie Gauthier-Umaña, Martín Ochoa, Moti Yung
Place of PublicationCham
PublisherSpringer International Publishing
Number of pages21
ISBN (Electronic)978-3-030-21568-2
ISBN (Print)978-3-030-21567-5
Publication statusPublished - 29 May 2019
Event17th International Conference on Applied Cryptography and Network Security - Bogotá, Colombia
Duration: 5 Jun 20197 Jun 2019

Publication series

NameLecture Notes in Computer Science
PublisherSpringer, Cham
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference17th International Conference on Applied Cryptography and Network Security
Abbreviated titleACNS 2019
Internet address

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