Paper 2021/165
Composition with Knowledge Assumptions
Thomas Kerber, Aggelos Kiayias, and Markulf Kohlweiss
Abstract
Zero-knowledge succinct non-interactive arguments (zk-SNARKs) rely on knowledge assumptions for their security. Meanwhile, as the complexity and scale of cryptographic systems continues to grow, the composition of secure protocols is of vital importance. The current gold standards of composable security, the Universal Composability and Constructive Cryptography frameworks cannot capture knowledge assumptions, as their core proofs of composition prohibit white-box extraction. In this paper, we present a formal model allowing the composition of knowledge assumptions. Despite showing impossibility for the general case, we demonstrate the model’s usefulness when limiting knowledge assumptions to few instances of protocols at a time. We finish by providing the first instance of a simultaneously succinct and composable zk-SNARK, by using existing results within our framework.
Metadata
- Available format(s)
-
PDF
- Category
- Foundations
- Publication info
- Preprint. MINOR revision.
- Keywords
- zero knowledgecompositionknowledge assumptions
- Contact author(s)
- papers @ tkerber org
- History
- 2021-02-17: received
- Short URL
- https://ia.cr/2021/165
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2021/165,
author = {Thomas Kerber and Aggelos Kiayias and Markulf Kohlweiss},
title = {Composition with Knowledge Assumptions},
howpublished = {Cryptology ePrint Archive, Paper 2021/165},
year = {2021},
note = {\url{https://eprint.iacr.org/2021/165}},
url = {https://eprint.iacr.org/2021/165}
}
