Concurrent Blind Signatures Without Random Oracles

Aggelos Kiayias, Hong-Sheng Zhou

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


We present a blind signature scheme that is efficient and provably secure without random oracles under concurrent attacks utilizing only four moves of short communication. The scheme is based on elliptic curve groups for which a bilinear map exists and on extractable and equivocal commitments. The unforgeability of the employed signature scheme is guaranteed by the LRSW assumption while the blindness property of our scheme is guaranteed by the Decisional Linear Diffie-Hellman assumption. We prove our construction secure under the above assumptions as well as Paillier’s DCR assumption in the concurrent attack model of Juels, Luby and Ostrovsky from Crypto ’97 using a common reference string. Our construction is the first efficient construction for blind signatures in such a concurrent model without random oracles. We present two variants of our basic protocol: first, a blind signature scheme where blindness still holds even if the public-key generation is maliciously controlled; second, a blind signature scheme that incorporates a “public-tagging” mechanism. This latter variant of our scheme gives rise to a partially blind signature with essentially the same efficiency and security properties as our basic scheme.
Original languageEnglish
Title of host publicationSecurity and Cryptography for Networks
Subtitle of host publication5th International Conference, SCN 2006, Maiori, Italy, September 6-8, 2006. Proceedings
EditorsRoberto De Prisco, Moti Yung
Place of PublicationBerlin, Heidelberg
PublisherSpringer Berlin Heidelberg
Number of pages14
ISBN (Electronic)978-3-540-38081-8
ISBN (Print)978-3-540-38080-1
Publication statusPublished - 2006

Publication series

NameLecture Notes in Computer Science
PublisherSpringer Berlin Heidelberg
ISSN (Print)0302-9743

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