Cryptology ePrint Archive: Report 2017/112

Zero-Knowledge Proxy Re-Identification Revisited

Xavier Bultel and Pascal Lafourcade

Abstract: Zero-knowledge proxy re-identification (ZK-PRI) has been introduced by Blaze et al. in 1998 together with two other well known primitives of recryptography, namely proxy re-encryption (PRE) and proxy re-signature (PRS). A ZK-PRI allows a proxy to transform an identification protocol for Alice into an identification protocol for Bob using a re-proof key. PRE and PRS have been largely studied in the last decade, but surprisingly, no results about ZK-PRI have been published since the pioneer paper of Blaze et al.. We first show the insecurity of this scheme: just by observing the communications Alice can deduce Bobís secret key. Then we give (i) definitions of the different families of ZK-PRI(bidirectional/unidirectional and interactive/non-interactive)(ii) a formal security model for these primitives and (iii) a concrete construction for each family. Moreover, we show that ZK-PRI can be used to manage the acces policy to several services that require a public key authentication.

Category / Keywords: cryptographic protocols /

Date: received 11 Feb 2017

Contact author: xavier bultel at yahoo fr

Available format(s): PDF | BibTeX Citation

Version: 20170214:183417 (All versions of this report)

Short URL: ia.cr/2017/112

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