[Resource Topic] 2020/504: Storing and Retrieving Secrets on a Blockchain

Welcome to the resource topic for 2020/504

Title:
Storing and Retrieving Secrets on a Blockchain

Authors: Vipul Goyal, Abhiram Kothapalli, Elisaweta Masserova, Bryan Parno, Yifan Song

Abstract:

Multiple protocols implementing exciting cryptographic functionalities using blockchains such as time-lock encryption, one-time programs and fair multi-party computation assume the existence of a cryptographic primitive called extractable witness encryption. Unfortunately, there are no known efficient constructions (or even constructions based on any well studied assumptions) of extractable witness encryption. In this work, we propose a protocol that uses a blockchain itself to provide a functionality that is effectively the same as extractable witness encryption. By making small adjustments to the blockchain code, it is possible to easily implement applications that rely on extractable witness encryption and existed only as theoretical designs until now. There is also potential for new applications. As a key building block, our protocol uses a new and highly efficient batched dynamic proactive secret sharing scheme which may be of independent interest. We provide a proof-of-concept implementation of the extractable witness encryption construction and the underlying dynamic proactive secret sharing protocol.

ePrint: https://eprint.iacr.org/2020/504

Talk: https://www.youtube.com/watch?v=fO13sdxkxxM

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .