To this end, we propose a unified formal model for (randomized) cryptographic accumulators which covers static and dynamic accumulators, their universal features and includes the notions of undeniability and indistinguishability. Additionally, we provide an exhaustive classification of all existing schemes. In doing so, it turns out that most accumulators are distinguishable. Fortunately, a simple, light-weight generic transformation allows to make many existing dynamic accumulator schemes indistinguishable. As this transformation, however, comes at the cost of reduced collision freeness, we additionally propose the first indistinguishable scheme that does not suffer from this shortcoming. Finally, we employ our unified model for presenting a black-box construction of commitments from indistinguishable accumulators as well as a black-box construction of indistinguishable, undeniable universal accumulators from zero-knowledge sets. Latter yields the first universal accumulator construction that provides indistinguishability.
Category / Keywords: static, dynamic, universal cryptographic accumulators, unified model, indistinguishability, undeniability, black-box constructions Original Publication (with major differences): CT-RSA 2015 Date: received 5 Feb 2015, last revised 5 Feb 2015 Contact author: david derler at iaik tugraz at Available format(s): PDF | BibTeX Citation Version: 20150214:085122 (All versions of this report) Short URL: ia.cr/2015/087 Discussion forum: Show discussion | Start new discussion