Efficient unlinkable sanitizable signatures from signatures with re-randomizable keys

Buch (Autor)
(Band aus einer Reihe)

Details zur Publikation

Autorinnen und Autoren: Fleischhacker N, Krupp J, Malavolta G, Schneider J, Schröder D, Simkin M, Malavolta G
Verlag: Springer Verlag
Jahr der Veröffentlichung: 2016
Titel der Reihe: Public-Key Cryptography - PKC 2016
Band: 9614
Seitenbereich: 301-330
ISBN: 9783662493830
Sprache: Englisch


In a sanitizable signature scheme the signer allows a designated third party, called the sanitizer, to modify certain parts of the message and adapt the signature accordingly. Ateniese et al. (ESORICS 2005) introduced this primitive and proposed five security properties which were formalized by Brzuska et al. (PKC 2009). Subsequently, Brzuska et al. (PKC 2010) suggested an additional security notion, called unlinkability which says that one cannot link sanitized message-signature pairs of the same document. Moreover, the authors gave a generic construction based on group signatures that have a certain structure. However, the special structure required from the group signature scheme only allows for inefficient instantiations. Here, we present the first efficient instantiation of unlinkable sanitizable signatures. Our construction is based on a novel type of signature schemes with re-randomizable keys. Intuitively, this property allows to re-randomize both the signing and the verification key separately but consistently. This allows us to sign the message with a re-randomized key and to prove in zero-knowledge that the derived key originates from either the signer or the sanitizer. We instantiate this generic idea with Schnorr signatures and efficient Σ-protocols, which we convert into noninteractive zero-knowledge proofs via the Fiat-Shamir transformation. Our construction is at least one order of magnitude faster than instantiating the generic scheme of Brzuska et al. with the most efficient group signature schemes.

FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Malavolta, Giulio
Lehrstuhl für Informatik 13 (Angewandte Kryptographie)
Schröder, Dominique Prof. Dr.
Lehrstuhl für Informatik 13 (Angewandte Kryptographie)


Fleischhacker, N., Krupp, J., Malavolta, G., Schneider, J., Schröder, D., Simkin, M., & Malavolta, G. (2016). Efficient unlinkable sanitizable signatures from signatures with re-randomizable keys. Springer Verlag.

Fleischhacker, Nils, et al. Efficient unlinkable sanitizable signatures from signatures with re-randomizable keys. Springer Verlag, 2016.


Zuletzt aktualisiert 2018-13-11 um 13:50