Practical compact E-cash

Man Ho Allen Au, Willy Susilo, Yi Mu

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

33 Citations (Scopus)


Compact e-cash schemes allow a user to withdraw a wallet containing k coins in a single operation, each of which the user can spend unlinkably. One big open problem for compact e-cash is to allow multiple denominations of coins to be spent efficiently without executing the spend protocol a number of times. In this paper, we give a (partial) solution to this open problem by introducing two additional protocols, namely, compact spending and batch spending. Compact spending allows spending all the k coins in one operation while batch spending allows spending any number of coins in the wallet in a single execution. We modify the security model of compact e-cash to accommodate these added protocols and present a generic construction. While the spending and compact spending protocol are of constant time and space complexities, complexities of batch spending is linear in the number of coins to be spent together. Thus, we regard our solution to the open problem as partial. We provide two instantiations under the q-SDH assumption and the LRSW assumption respectively and present security arguments for both instantiations in the random oracle model.
Original languageEnglish
Title of host publicationInformation Security and Privacy - 12th Australasian Conference, ACISP 2007, Proceedings
Number of pages15
Publication statusPublished - 1 Dec 2007
Externally publishedYes
Event12th Australasian Conference on Information Security and Privacy, ACISP2007 - Townsville, Australia
Duration: 2 Jul 20074 Jul 2007

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume4586 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference12th Australasian Conference on Information Security and Privacy, ACISP2007


  • Bilinear pairings
  • Compact
  • Constant-size
  • E-cash

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)


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