Efficient Invisible and Unlinkable Sanitizable Signatures

Bultel X, Lafourcade P, Lai RWF, Malavolta G, Schröder D, Thyagarajan SAK (2019)

Publication Type: Book chapter / Article in edited volumes

Publication year: 2019

Journal

Publisher: Springer Verlag

Edited Volumes: Public-Key Cryptography – PKC 2019 - 22nd IACR International Conference on Practice and Theory of Public-Key Cryptography, Proceedings

Series: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Book Volume: 11442 LNCS

Pages Range: 159-189

DOI: 10.1007/978-3-030-17253-4_6

Abstract

Sanitizable signatures allow designated parties (the sanitizers) to apply arbitrary modifications to some restricted parts of signed messages. A secure scheme should not only be unforgeable, but also protect privacy and hold both the signer and the sanitizer accountable. Two important security properties that are seemingly difficult to achieve simultaneously and efficiently are invisibility and unlinkability. While invisibility ensures that the admissible modifications are hidden from external parties, unlinkability says that sanitized signatures cannot be linked to their sources. Achieving both properties simultaneously is crucial for applications where sensitive personal data is signed with respect to data-dependent admissible modifications. The existence of an efficient construction achieving both properties was recently posed as an open question by Camenisch et al. (PKC’17). In this work, we propose a solution to this problem with a two-step construction. First, we construct (non-accountable) invisible and unlinkable sanitizable signatures from signatures on equivalence classes and other basic primitives. Second, we put forth a generic transformation using verifiable ring signatures to turn any non-accountable sanitizable signature into an accountable one while preserving all other properties. When instantiating in the generic group and random oracle model, the efficiency of our construction is comparable to that of prior constructions, while providing stronger security guarantees.

Authors with CRIS profile

Involved external institutions

University of Clermont Auvergne France (FR) Université Toulouse III - Paul Sabatier France (FR)

How to cite

APA:

Bultel, X., Lafourcade, P., Lai, R.W.F., Malavolta, G., Schröder, D., & Thyagarajan, S.A.K. (2019). Efficient Invisible and Unlinkable Sanitizable Signatures. In Dongdai Lin, Kazue Sako (Eds.), Public-Key Cryptography – PKC 2019 - 22nd IACR International Conference on Practice and Theory of Public-Key Cryptography, Proceedings. (pp. 159-189). Springer Verlag.

MLA:

Bultel, Xavier, et al. "Efficient Invisible and Unlinkable Sanitizable Signatures." Public-Key Cryptography – PKC 2019 - 22nd IACR International Conference on Practice and Theory of Public-Key Cryptography, Proceedings. Ed. Dongdai Lin, Kazue Sako, Springer Verlag, 2019. 159-189.

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