Paper 2024/264 Original: eprint.iacr.org/2024/264 ↗
Extractable Witness Encryption for KZG Commitments and Efficient Laconic OT
Abstract
We present a concretely efficient and simple extractable witness encryption scheme for KZG polynomial commitments. It allows to encrypt a message towards a triple $(\mathsf{com}, \alpha, \beta)$, where $\mathsf{com}$ is a KZG commitment for some polynomial $f$. Anyone with an opening for the commitment attesting $f(\alpha) = \beta$ can decrypt, but without knowledge of a valid opening the message is computationally hidden. Our construction is simple and highly efficient. The ciphertext is only a single group element. Encryption and decryption both require a single pairing evaluation and a constant number of group operations. Using our witness encryption scheme, we construct a simple and highly efficient laconic OT protocol, which significantly outperforms the state of the art in most important metrics.
Metadata
- Available format(s)
PDF- Category
- Cryptographic protocols
- Publication info
- Preprint.
- History
- 2024-03-13: last updated
- 2024-02-16: published
- Short URL
- https://ia.cr/2024/264
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2024/264,
author = {Nils Fleischhacker and Mathias Hall-Andersen and Mark Simkin},
title = {Extractable Witness Encryption for KZG Commitments and Efficient Laconic OT},
howpublished = {Cryptology {ePrint} Archive, Paper 2024/264},
year = {2024},
url = {https://eprint.iacr.org/2024/264}
}