Paper 2017/1168 Original: eprint.iacr.org/2017/1168 ↗
Itsuku: a Memory-Hardened Proof-of-Work Scheme
Abstract
Proof-of-Work (PoW) schemes allow to limit access to resources or to share rewards for crypto-currency mining. The MTP-Argon2 PoW by Biryukov and Khovratovich is loosely based on the Argon2 memory-hard password hashing function. Several attacks have been published. We introduce a new transposed parallel implementation attack which achieves higher performance by circumventing apparent bandwidth requirements. We then present Itsuku, a new scheme that fixes known issues by changing MTP-Argon2 parameters and adds new operations to improve memory hardness. Our scheme is built on a simple security criterion: any implementation which requires half the memory or less should induce at least a times-64 computation cost for difficulty d <= 100. The Itsuku proof size is typically 1/16 th of the initial scheme, while providing better memory hardness. We also describe high-end hardware designs for MTP-Argon2 and Itsuku.
Metadata
- Available format(s)
PDF- Category
- Cryptographic protocols
- Publication info
- Preprint.
- History
- 2017-12-01: last updated
- 2017-12-01: published
- Short URL
- https://ia.cr/2017/1168
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2017/1168,
author = {Fabien Coelho and Arnaud Larroche and Baptiste Colin},
title = {Itsuku: a Memory-Hardened Proof-of-Work Scheme},
howpublished = {Cryptology {ePrint} Archive, Paper 2017/1168},
year = {2017},
url = {https://eprint.iacr.org/2017/1168}
}