Authors

David Derler (IAIK, Graz University of Technology), Henrich C. Pöhls (Chair of IT-Security - Institute of IT-Security and Security Law, University of Passau ), Kai Samelin (IBM Zurich & TU Darmstadt) and Daniel Slamanig (IAIK, Graz University of Technology)

Abstract

A redactable signature scheme (RSS) allows removing parts of a signed message by any party without invalidating the respective signature. State-of-the-art constructions thereby focus on messages represented by one specific data-structure, e.g., lists, sets or trees, and adjust the security model accordingly. To overcome the necessity for this myriad of models, we present a general framework covering arbitrary data-structures and even more sophisticated possibilities. For example, we cover fixed elements which must not be redactable and dependencies between elements. Moreover, we introduce the notion of designated redactors, i.e., the signer can give some extra information to selected entities which become redactors. In practice, this often allows to obtain more efficient schemes. We then present two RSS; one for sets and one for lists, both constructed from any EUF-CMA secure signature scheme and indistinguishable cryptographic accumulators in a black-box way and show how the concept of designated redactors can be used to increase the efficiency of these schemes. Finally, we present a black-box construction of a designated redactor RSS by combining an RSS for sets with non-interactive zero-knowledge proof systems. All the three constructions presented in this paper provide transparency, which is an important property, but quite hard to achieve, as we also conceal the length of the original message and the positions of the redactions.

Venue

18th International Conference on Information Security and Cryptology (ICISC 2015)  (http://www.icisc.org/icisc15/asp/index.html)

Place and Date

Seoul, Korea, November 25th-27th 2015

Publication Reference

David Derler, Henrich C. Pöhls, Kai Samelin, Daniel Slamanig. "A General Framework for Redactable Signatures and New Constructions", Information Security and Cryptology - ICISC 2015 - 18th International Conference, Seoul, Korea, November 25-27, 2015.

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Bibtex

@inproceedings{dpss15,
 Author     = {David Derler, Henrich C. P{\"{o}}hls, Kai Samelin, Daniel Slamanig},
 Title      = {{A General Framework for Redactable Signatures and New Constructions}},
 Booktitle  = {Information Security and Cryptology - ICISC 2015 - 18th International Conference, Seoul, Korea, November 25-27.},
 Year       = {2015},
 Publisher  = {Springer}
 }