Paper 2019/250
Function-Dependent Commitments from Homomorphic Authenticators
Lucas Schabhüser, Denis Butin, and Johannes Buchmann
Abstract
In cloud computing, delegated computing raises the security issue of guaranteeing data authenticity during a remote computation. In this context, the recently introduced function-dependent commitments (FDCs) are the only approach providing both fast correctness verification, information-theoretic input-output privacy, and strong unforgeability. Homomorphic authenticators--- the established approach to this problem ---do not provide information-theoretic privacy and always reveal the computation's result upon verification, thus violating output privacy. Since many homomorphic authenticator schemes already exist, we investigate the relation between them and FDCs to clarify how existing schemes can be supplemented with information-theoretic output privacy. Specifically, we present a generic transformation turning any structure-preserving homomorphic authenticator scheme into an FDC scheme. This facilitates the design of multi-party computation schemes with full information-theoretic privacy. We also introduce a new structure-preserving, linearly homomorphic authenticator scheme suitable for our transformation. It is the first both context hiding and structure-preserving homomorphic authenticator scheme. Our scheme is also the first structure-preserving homomorphic authenticator scheme to achieve efficient verification.
Metadata
- Available format(s)
- Category
- Public-key cryptography
- Publication info
- Preprint. MINOR revision.
- Keywords
- Homomorphic AuthenticatorsCommitmentsDelegated Computation
- Contact author(s)
-
lschabhueser @ cdc tu-darmstadt de
dbutin @ cdc tu-darmstadt de - History
- 2019-02-28: received
- Short URL
- https://ia.cr/2019/250
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2019/250, author = {Lucas Schabhüser and Denis Butin and Johannes Buchmann}, title = {Function-Dependent Commitments from Homomorphic Authenticators}, howpublished = {Cryptology {ePrint} Archive, Paper 2019/250}, year = {2019}, url = {https://eprint.iacr.org/2019/250} }